https://wiki.cosmos.esa.int/planck-legacy-archive/api.php?action=feedcontributions&user=Azacchei&feedformat=atomPlanck Legacy Archive Wiki - User contributions [en-gb]2024-03-28T22:42:30ZUser contributionsMediaWiki 1.31.6https://wiki.cosmos.esa.int/planck-legacy-archive/index.php?title=Map-making_LFI&diff=14134Map-making LFI2018-07-06T16:04:34Z<p>Azacchei: /* Low-resolution maps and noise covariance matrices */</p>
<hr />
<div>==Mapmaking==<br />
The inputs to the mapmaking procedure consist of the calibrated timelines, along with the corresponding pointing information.<br />
The main output consists of temperature and polarization maps. <br />
An important part of the mapmaking step is the removal of correlated 1/<i>f</i> noise.<br />
<br />
LFI maps were constructed with the MADAM mapmaking code, version 3.7.4.<br />
The code is based on a generalized destriping technique, where the correlated noise component is modelled as a sequence of constant offset "baselines". <br />
The baseline solution is constrained by a noise filter.<br />
As auxiliary information, the code produces a hit-count map and a white noise covariance matrix.<br />
No beam information is used, with the signal being simply assigned to the pixel where the centre of the beam falls.<br />
<br />
The chosen baseline length was 1s for the 44GHz and 70GHz maps, 0.25s for the 30GHz map. This gives good noise removal,<br />
without being computationally burdensome.<br />
The noise filter was built according to the noise parameters (see noise section).<br />
Flagged samples were excluded from the analysis. The Galaxy region was masked out in the destriping phase, to reduce errors arising from strong signal gradients. Radiometers were combined according to the horn-uniform weighting scheme to minimize systematics. The polarization component was included in the analysis and is part of this release.<br />
A detailed description of the mapmaking procedure is given in {{PlanckPapers|planck2013-p02}}, {{PlanckPapers|planck2014-a03}}, {{PlanckPapers|planck2014-a07}} no relevant changes has been applyed in the 2018 release. See also the section on [[Frequency Maps]].<br />
<br />
The maps are in HEALPix format, at resolution <i>N</i><sub>side</sub>=1024 for all frequencies with an additional map at <i>N</i><sub>side</sub>=2048 for the LFI 70GHz channel, in the nested pixelization scheme.<br />
Unobserved pixels are marked by a special value.<br />
<br />
The released maps are in Galactic coordinates.<br />
The conversion between ecliptic and Galactic coordinates is described by the rotation matrix<br />
<math><br />
\newcommand{\Re}{\mathrm{Re}\,}<br />
\newcommand{\pFq}[5]{{}_{#1}\mathrm{F}_{#2} \left( \genfrac{}{}{0pt}{}{#3}{#4} \bigg| {#5} \right)}<br />
</math><br />
<br />
:<math> <br />
\begin{align}<br />
\label{def:Rot_matrix}<br />
\left (\begin{matrix}<br />
-0.054882486 & 0.494116468 & -0.867661702\\ <br />
-0.993821033 & -0.110993846 & -0.000346354\\ <br />
-0.096476249 & 0.86228144 & 0.497154957 <br />
\end{matrix} \right).<br />
\end{align} <br />
</math> <br />
The conversion was applied to the input pointing data, prior to the construction of the map.<br />
<br />
==Low-resolution maps and noise covariance matrices==<br />
<br />
To fully exploit the information contained in the large-scale structure of the microwave sky, pixel-pixel covariances are needed in the maximum likelihood estimation of the CMB power spectrum. However, full covariance matrices are impossible to employ at the native map resolution due to resource limitations. A low-resolution data set is therefore required for the low-&#8467; analysis. This data set has been packed into three different files, one per frequency, called "LFI_NoiseCovMat_0??_0016_R3.00.tgz", that can be downloaded from the Cosmology section of the Planck Legacy Archive. <br />
They consist of low-resolution maps, and descriptions of residual noise present in those maps given by pixel-pixel noise covariance matrices (NCVMs).<br />
Note the in the 2018 release the Low-resolution maps full mission coverage, excluding Surveys 2 and 4 has not been used. We release them for crosschecking purposes with respect 2015 release.<br />
<br />
{| border="1" cellpadding="3" cellspacing="0" align="center" style="text-align:left" width=800px<br />
|+ Contents of '''LFI_NoiseCovMat_0??_0016_R3.20.tgz'''<br />
|- bgcolor="ffdead"<br />
! Filenames || Comment<br />
|- <br />
| LFI_SkyMap_0??_0016_coswin_DX12_full_regnoise.fits || Low-resolution maps. Full mission coverage.<br />
|- <br />
| LFI_SkyMap_0??_0016_coswin_DX12_Corrected_full_regnoise.fits || Low-resolution maps BandPass Corrected. Full mission coverage. Corrected for the BandPass.<br />
|- <br />
| LFI_SkyMap_0??_0016_coswin_DX12_s1-s3-s5-s6-s7-s8_regnoise.fits || Low-resolution maps. Full mission coverage, excluding Surveys 2 and 4. <br />
|- <br />
| LFI_SkyMap_0??_0016_coswin_DX12_Corrected_s1-s3-s5-s6-s7-s8_regnoise.fits || Low-resolution maps. Full mission coverage, excluding Surveys 2 and 4. Corrected for the BandPass.<br />
|- <br />
| offset_covmat_toast_nside64T16_coswin_025sec_??GHz_DX12_full_bin.dat || Low-resolution noise covariance matrices. Regularization noise added. Format: C unformatted.<br />
|- <br />
| offset_covmat_toast_nside64T16_coswin_025sec_??GHz_DX12_s1-s3-s5-s6-s7-s8_bin.dat || Low-resolution noise covariance matrices. Regularization noise added. Format: C unformatted.<br />
|- <br />
| covmat_toast_nside64T16_coswin_025sec_??GHz_DX12_full_bin.dat || Low-resolution noise covariance matrices. No regularization noise added. Format: C unformatted.<br />
|- <br />
| covmat_toast_nside64T16_coswin_025sec_??GHz_DX12_s1-s3-s5-s6-s7-s8_bin.dat || Low-resolution noise covariance matrices. No regularization noise added. Format: C unformatted.<br />
|- <br />
| mask_comm17Tv2_pol_R2.2x_ns16_nest.fits || Low-resolution Mask 2.2.<br />
|- <br />
| mask_comm17Tv2_pol_R1.8x_ns16_nest.fits || Low-resolution Mask 1.8.<br />
|- <br />
| offset_RESCALED_base_bestfit_cov_IQU.da || Rescaled noise ONLY for 70 GHz. C unformatted.<br />
|- <br />
|}<br />
<br />
<br />
<br />
The low-resolution data set can currently be utilized efficiently only at resolution <i>N</i><sub>side</sub> = 16, or lower. All the low-resolution data products are produced at this target resolution.<br />
===Low-resolution maps===<br />
A number of different schemes to obtain the low-resolution maps are discussed in {{BibCite|keskitalo2013}}. We chose to downgrade the maps using the inverse noise weighting, no changes on the procedure has been applyed to the 2018 release. This is discussed further in {{PlanckPapers|planck2013-p02}} {{PlanckPapers|planck2014-a07}}.<br />
====Inputs====<br />
We took the high-resolution maps described in [[Map-making LFI#Map-making|Map-making]] and [[Frequency Maps]], and the corresponding 3&times;3 matrices as an input for this analysis step.<br />
<br />
====Production====<br />
The high-resolution maps were downgraded to <i>N</i><sub>side</sub> = 16 using inverse noise weights (given by the 3&times;3 matrices), and subsequently the temperature part was smoothed with a symmetric Gaussian beam with FWHM = 440arcmin.<br />
<br />
===Noise covariance matrices===<br />
<br />
The statistical description of the residual noise in the maps is given in the form of a pixel-to-pixel noise covariance matrix (NCVM), as described in {{BibCite|keskitalo2013}}. <br />
<br />
====Inputs====<br />
<br />
The noise model was determined by three noise parameters: the white noise level &sigma;; slope; and knee frequency <i>f</i><sub>knee</sub>. We actually used three sets of noise parameters, one for the entire mission (noise parameters are listed in Table 1), and one for each sky survey (SS1 and SS2).<br />
<br />
We used the same pointing as in the noise Monte Carlo simulations. See the description in [[Map-making LFI#Noise Monte Carlo Simulation#Inputs|Noise Monte Carlo Simulation Inputs]].<br />
<br />
We used the gap files produced during the making of the flight maps to leave out samples that were flagged as bad for various reasons.<br />
<br />
====Production====<br />
<br />
The output of the NCVM module of MADAM mapmaker are inverse NCVMs. Since the inverse matrices are additive, we divided the computations into a number of small chunks to save computational resources. We first calculated one inverse NCVM per radiometer per survey at resolution <i>N</i><sub>side</sub>=32, and then combined these individual inverse matrices to form the actual inverse matrices. The mapmaking parameters were almost identical to the standard mapmaking runs. The differing parameter values are listed below:<br />
* baseline lengths were 0.25s for 30GHzand 1.0s for 44GHz, and 70GHz;<br />
* the calculations were performed at resolution <i>N</i><sub>side</sub> = 64;<br />
* no destriping mask was applied;<br />
* the horns were weighted optimally.<br />
<br />
To obtain the noise covariance from its inverse, the matrices are inverted using the eigen decomposition of a matrix. The monopole of the temperature map cannot be resolved by the mapmaker, and thus the matrix becomes singular. This ill-determined mode is left out of the analysis.<br />
<br />
Having calculated the eigen decomposition in the previous step, we can apply the same linear operators to modify the eigenvectors as were applied to the high-resolution maps while downgrading them. The eigenvectors are downgraded to <i>N</i><sub>side</sub> = 16 using inverse noise weights, and subsequently the temperature part is smoothed with a symmetric Gaussian beam with FWHM = 440arcmin.<br />
<br />
The final matrices are then recomposed from the original eigenvalues and modified eigenvectors.<br />
<br />
The low-resolution noise covariance matrices:<br />
* are C binary format files;<br />
* are organized in block form,<br />
<math><br />
\newcommand{\Re}{\mathrm{Re}\,}<br />
\newcommand{\pFq}[5]{{}_{#1}\mathrm{F}_{#2} \left( \genfrac{}{}{0pt}{}{#3}{#4} \bigg| {#5} \right)}<br />
</math><br />
<math><br />
\begin{align}<br />
\label{def:Block_form}<br />
\left (\begin{matrix}<br />
II & IQ & IU \\<br />
QI & QQ & QU \\<br />
UI & UQ & UU<br />
\end{matrix} \right);<br />
\end{align} <br />
</math><br />
<br />
* are in the HEALPix nested pixelisation scheme (with resolution is <i>N</i><sub>side</sub> = 16, and thus there are <i>N</i><sub>pix</sub> = 3072 pixels);<br />
* are in Galactic coordinates;<br />
* have K<sub>CMB</sub> units.<br />
<br />
==Half-ring jackknife noise maps==<br />
<br />
===Overview===<br />
In the 2018 release we follow the same procedure as in {{PlanckPapers|planck2014-a03||Planck-2015-A03}} in order to estimate the noise directly at the map level and in the angular power spectra.<br />
<br />
Briefly, instead of using the full time-ordered data as described above, we produced two sets of maps using either only the first half of each pointing period (map named <b>j</b><sub>1</sub> below) or only the second half of each pointing period (map named <b>j</b><sub>2</sub>). At each pixel <i>p</i>, these half-ring jackknife maps <b>j</b><sub>1</sub> and <b>j</b><sub>2</sub> contain the same sky signal, since they result from the same scanning pattern on the sky. However, because of instrumental noise, the maps <b>j</b><sub>1</sub> and <b>j</b><sub>2</sub> are not identical.<br />
<br />
We estimated the noise level in each map <b>m</b> made using the full (ring) data, by constructing a half-ring difference map<br />
<br />
<math>\mathbf{n_{m}}(p) = [ \mathbf{j_1}(p) - \mathbf{j_2}(p)] \ / \ \mathbf{w_{\rm hit}}(p)\,,</math><br />
<br />
with weights<br />
<br />
<math>\mathbf{w_{hit}}(p) = \sqrt{ \mathbf{hit_{full}}(p) \left[ \frac{1}{\mathbf{hit_1}(p)} +<br />
\frac{1}{\mathbf{hit_2}(p)} \right]}\,</math>.<br />
<br />
Here <b>hit</b><sub>full</sub>(<i>p</i>) = <b>hit</b><sub>1</sub>(<i>p</i>) + <b>hit</b><sub>2</sub>(<i>p</i>)<br />
is the hit count at pixel <i>p</i> in the full map <b>m</b>, while <b>hit</b><sub>1</sub> and <b>hit</b><sub>2</sub> are the hit counts of <b>j</b><sub>1</sub> and <b>j</b><sub>2</sub>, respectively. The weight factor <b>w</b><sub>hit</sub>(<i>p</i>) is equal to 2 only in those pixels where <b>hit</b><sub>1</sub>(<i>p</i>) = <b>hit</b><sub>2</sub>(<i>p</i>) . In a typical pixel, <b>hit</b><sub>1</sub>(<i>p</i>) will differ slightly from<br />
<b>hit</b><sub>2</sub>(<i>p</i>) and hence the weight factor is <b>w</b><sub>hit</sub>(<i>p</i>)>2.<br />
<br />
The half-ring difference maps <b>n</b><sub>m</sub> are the most direct measure of the noise in the actual maps. The other noise estimates (NCVM and noise Monte Carlo) rely on specific modelling of the noise and this modelling can be validated by comparing to the half-ring difference maps. However, the half-ring difference maps can only capture the noise that varies faster than half of the duration of the pointing period, i.e., the noise whose frequency is approximately <i>f</i> > 1/20min = 0.85mHz.<br />
<br />
We calculated the noise maps <b>n</b><sub>m</sub>, from half-ring "jackknife" maps for temperature (<i>I</i>) and polarization (<i>Q</i> and <i>U</i>) and as a first quality check of the maps (and as one of the tests of the whole data processing pipeline up to the map level) tested both numerically and visually that these noise maps divided pixel-by-pixel by the square root of the white noise covariance maps were approximately Gaussian with variance near to unity. Temperature noise maps for the nominal survey and for the first and second sky surveys are shown in the next subsection. Furthermore we calculated from the noise maps the temperature and polarization (E and B mode) auto-correlation and cross-correlation noise angular power spectra using HEALPix anafast and compared to these the results from the white noise covariance matrices and from the noise Monte Carlo simulations. A similar comparison was made between downgraded half-ring noise maps, downgraded noise Monte Carlo maps, and the low-resolution noise covariance maps. Detailed results are presented in {{PlanckPapers|planck2016-l02}}.<br />
<br />
===Comparison of noise estimates using Half-Ring===<br />
<br />
Here we compare noise angular power spectra estimated from half-ring difference maps (red), white noise covariance maps (black dash-dotted lines), and 100 full noise Monte Carlo simulations (grey band showing range for 16th and 84th quantiles of noise simulations, and the black solid lines giving the median, i.e., 50th quantile, of distributions). See the next section for details of noise Monte Carlo simulations. From top to botto we show ''TT'', ''EE'' and ''BB'' power spectra for 30 GHz (left), 44 GHz (centre), and 70 GHz (right). Half-ring spectra are binned with <math>\mathbf{\Delta}l = 25 </math> for <math> l \mathbf{\geq} 75 </math>.<br />
<br />
[[File:test_ffp10.png|thumb|800px|center|<b>Consistency Check</b>]]<br />
<br />
Below the null-tests comparing power spectra from survey differences to those from teh half-ring maps are showed. Difefrences are: left, Survey 1 - Survey 2; Middle , Survey 1- Survey 3; and right, Survey 1 - Survey4. these are for 30 GHz (top), 44 GHz (middle), and 70 GHz (bottom), for both ''TT'' and ''EE'' power spectra. There is a significant improvement in Surve1 - Survey 2 and Survey 1 - Survey 4 at 30 GHz, especially in ''EE''. See {{PlanckPapers|planck2016-l02}} for further details.<br />
<br />
[[File:nullhr1517.png|thumb|800px|center|<b>Null Test</b>]]<br />
<br />
<br />
====High-ell average noise relative to white noise estimate====<br />
<br />
The figure below is the same as the previous figures, but here the noise comparison is made from the high &#8467; tails of the angular power spectra, where the white noise dominates. We have taken the average of <i>C</i><sub>&#8467;</sub> from multipoles between 1150 and 1800 for both temperature and polarization and tehn comparing with the WNCVM. As already shown in previous releases, there is still an excess of 1/f noise, meaning tha both the real data and the noise MCs predict slightly larger noise than the WNCVM. It is important to note that such noise excess is reduced considerably with respect to the 2015 release.<br />
<br />
[[File:high.png|thumb|800px|center|<b>Ratio at high multipoles</b>]]<br />
<br />
==Noise Monte Carlo simulations==<br />
<br />
===Overview===<br />
Calculating and handling full pixel-to-pixel noise covariance matrices for Planck maps if feasible only at low resolution.<br />
To support the analysis of high-resolution maps, a Monte Carlo set of noise maps were produced. These maps were produced from noise timelines using the same map-making procedure as for the flight data. In the noise Monte Carlo it was possible to follow exactly the mapmaking procedure used for the flight maps, whereas for the calculation of noise covariance matrices some approximations had to be made.<br />
Such noise Monte Carlos were produced at two levels of the analysis: (1) LFI Monte Carlo (MC) as part of the LFI data processing procedure; and (2) Full Focal Plane (FFP) Monte Carlos as part of the joint HFI/LFI data processing. This page describes the LFI noise MCs. For the FFP MC, see [[HL-sims]] and [[Simulation data]].<br />
<br />
===Inputs===<br />
The noise MC uses a three-parameter noise model, consisting of white noise level (&sigma;), slope, and knee frequency (<i>f</i><sub>knee</sub>)). Here the noise consists of white noise and correlated 1/<i>f</i> noise, with a power spectrum<br />
<br />
:<math> P(f) = \frac{2\sigma^2}{f_\mathrm{sample}}\left(\frac{f}{f_\mathrm{knee}}\right)^\mathrm{slope} </math>,<br />
<br />
where <i>f</i><sub>sample</sub> is the sampling frequency of the instrument. The noise parameters were determined separately for each radiometer, as described in the section [[TOI processing LFI#Noise| Noise]] above, assuming they stayed constant over the mission. <br />
<br />
The detector pointing was reconstructed from satellite pointing information, focal-plane geometry, pointing correction (tilt angle), and sample timing, using Level-S simulation software. The same pointing solution (two focal planes) was used as for the LFI flight maps. Due to numerical accuracy, the detector pointing in the noise MC was not exactly the same as for the flight maps, so some data samples (of the order of one in a thousand) whose pointing was near the pixel boundary ended up assigned to the neighbouring pixel. During mapmaking from the flight data, a "gap file" was produced to represent the samples that were omitted from mapmaking due to various flags. This gap file was used in the noise MC instead of the full set of flags. The flight mapmaking procedure used destriping masks to prevent regions of strong signal gradients from contributing to the noise baseline solution. These same destriping masks (one for each frequency channel) were used for the noise MC.<br />
<br />
===Production===<br />
The noise was generated internally in the Madam mapmaking code using a stochastic differential equation (SDE) method, to avoid time-consuming writing and reading of noise timelines to and from disk. Noise for each pointing period was generated separately, using a double-precision random number seed constructed from the realization number, radiometer number, and the pointing period number; this allowed for regeneration of the same noise realization when needed. White noise and 1/<i>f</i> noise were generated separately. <br />
<br />
The same mapmaking code (Madam) with the same parameter settings was used for the noise MC as for the flight maps.<br />
In addition to the destriped maps from the full noise (output maps), binned maps from just the white noise (binned white noise maps) were produced; they represent the white noise part of the output maps. The difference between these two maps represents the residual correlated noise in the output map. The maps were made at HEALPix resolution <i>N</i><sub>side</sub> = 1024 for all LFI frequency channels and also at HEALPix resolution <i>N</i><sub>side</sub> = 2048 for the 70 GHz channel.<br />
For low-resolution analysis, these maps were downgraded (and the temperature part was smoothed) to <i>N</i><sub>side</sub> = 32 and <i>N</i><sub>side</sub> = 16.<br />
<br />
In addition to frequency maps for the nominal survey, also single-survey and 70 GHz horn-pair maps were produced in the noise MC. For each case 102-1026 realizations were produced.<br />
<br />
===Usage===<br />
<br />
These noise Monte Carlo maps were used for a number of purposes in LFI data analysis. They were compared to the low-resolution noise covariance matrices, generated for the same noise model, in order to reveal the impact of the approximations in the noise covariance matrix calculation. They were compared to the half-ring noise maps to see how well the noise model matches the noise in the flight maps (noting, however, that the half-ring noise maps misrepresent the lowest noise frequencies in the flight maps, and contain some effects from the sky signal). They were also used in power spectrum estimation and non-Gaussianity estimation.<br />
<br />
===Examples===<br />
<br />
As an example, we show below images of the first realization of the 70GHz frequency map noise for the nominal survey. The images are in the order: destriped full noise; binned white noise; and residual correlated noise. Note that it is difficult to see any difference between the first two images, since the residual correlated noise is more than an order of magnitude below the white noise level. The units here are K<sub>CMB</sub>. <br />
<br />
<br />
<br />
[[File:LFI_4_5_5_4_madam_mask_1sec_DB10_1_noise_70GHz_all_DX9delta_nom_1024outmap.00000.gif|thumb|800px|center|<b>Destriped full noise.</b>]]<br />
[[File:LFI_4_5_5_4_madam_mask_1sec_DB10_1_white_70GHz_all_DX9delta_nom_1024binmap.00000.gif|thumb|800px|center|<b>Binned white noise.</b>]]<br />
[[File:LFI_4_5_5_4_madam_mask_1sec_DB10_1_rcnoise_70GHz_all_DX9delta_nom_1024map.00000.gif|thumb|800px|center|<b>Residual correlated noise.</b>]]<br />
<br />
<br />
The following two images show the statistics of the angular power spectra of 101 realizations of the 70 GHz frequency map noise for the nominal survey. The thick black line shows the median <i>C</i><sub>&#8467;</sub>, while the green line the mean <i>C</i><sub>&#8467;</sub>. Thin black lines show the minimum, 16th percentile, 84th percentile, and the maximum <i>C</i><sub>&#8467;</sub>. The red line is the 102nd realization. The first plot is for the full noise in the output map, while the second plot is for the residual correlated noise.<br />
<br />
[[File:LFI_4_5_5_4_cl_TT_stat_noisemc101_1sec_70GHz_all_DX9delta_nom.png|thumb|800px|center|<b>Full noise.</b>]]<br />
[[File:LFI_4_5_5_4_cl_TT_stat_rcnoisemc101_1sec_70GHz_all_DX9delta_nom.png|thumb|800px|center|<b>Residual correlated noise.</b>]]<br />
<br />
==References==<br />
<br />
<br />
<References /><br />
<br />
<br />
<br />
<br />
[[Category:LFI data processing|004]]</div>Azaccheihttps://wiki.cosmos.esa.int/planck-legacy-archive/index.php?title=Map-making_LFI&diff=14126Map-making LFI2018-07-06T15:23:37Z<p>Azacchei: /* Low-resolution maps and noise covariance matrices */</p>
<hr />
<div>==Mapmaking==<br />
The inputs to the mapmaking procedure consist of the calibrated timelines, along with the corresponding pointing information.<br />
The main output consists of temperature and polarization maps. <br />
An important part of the mapmaking step is the removal of correlated 1/<i>f</i> noise.<br />
<br />
LFI maps were constructed with the MADAM mapmaking code, version 3.7.4.<br />
The code is based on a generalized destriping technique, where the correlated noise component is modelled as a sequence of constant offset "baselines". <br />
The baseline solution is constrained by a noise filter.<br />
As auxiliary information, the code produces a hit-count map and a white noise covariance matrix.<br />
No beam information is used, with the signal being simply assigned to the pixel where the centre of the beam falls.<br />
<br />
The chosen baseline length was 1s for the 44GHz and 70GHz maps, 0.25s for the 30GHz map. This gives good noise removal,<br />
without being computationally burdensome.<br />
The noise filter was built according to the noise parameters (see noise section).<br />
Flagged samples were excluded from the analysis. The Galaxy region was masked out in the destriping phase, to reduce errors arising from strong signal gradients. Radiometers were combined according to the horn-uniform weighting scheme to minimize systematics. The polarization component was included in the analysis and is part of this release.<br />
A detailed description of the mapmaking procedure is given in {{PlanckPapers|planck2013-p02}}, {{PlanckPapers|planck2014-a03}}, {{PlanckPapers|planck2014-a07}} no relevant changes has been applyed in the 2018 release. See also the section on [[Frequency Maps]].<br />
<br />
The maps are in HEALPix format, at resolution <i>N</i><sub>side</sub>=1024 for all frequencies with an additional map at <i>N</i><sub>side</sub>=2048 for the LFI 70GHz channel, in the nested pixelization scheme.<br />
Unobserved pixels are marked by a special value.<br />
<br />
The released maps are in Galactic coordinates.<br />
The conversion between ecliptic and Galactic coordinates is described by the rotation matrix<br />
<math><br />
\newcommand{\Re}{\mathrm{Re}\,}<br />
\newcommand{\pFq}[5]{{}_{#1}\mathrm{F}_{#2} \left( \genfrac{}{}{0pt}{}{#3}{#4} \bigg| {#5} \right)}<br />
</math><br />
<br />
:<math> <br />
\begin{align}<br />
\label{def:Rot_matrix}<br />
\left (\begin{matrix}<br />
-0.054882486 & 0.494116468 & -0.867661702\\ <br />
-0.993821033 & -0.110993846 & -0.000346354\\ <br />
-0.096476249 & 0.86228144 & 0.497154957 <br />
\end{matrix} \right).<br />
\end{align} <br />
</math> <br />
The conversion was applied to the input pointing data, prior to the construction of the map.<br />
<br />
==Low-resolution maps and noise covariance matrices==<br />
<br />
To fully exploit the information contained in the large-scale structure of the microwave sky, pixel-pixel covariances are needed in the maximum likelihood estimation of the CMB power spectrum. However, full covariance matrices are impossible to employ at the native map resolution due to resource limitations. A low-resolution data set is therefore required for the low-&#8467; analysis. This data set has been packed into three different files, one per frequency, called "LFI_NoiseCovMat_0??_0016_R3.00.tgz", that can be downloaded from the Cosmology section of the Planck Legacy Archive. <br />
They consist of low-resolution maps, and descriptions of residual noise present in those maps given by pixel-pixel noise covariance matrices (NCVMs).<br />
Note the in the 2018 release the Low-resolution maps full mission coverage, excluding Surveys 2 and 4 has not been used. We release them for crosschecking purposes with respect 2015 release.<br />
<br />
{| border="1" cellpadding="3" cellspacing="0" align="center" style="text-align:left" width=800px<br />
|+ Contents of '''LFI_NoiseCovMat_0??_0016_R3.10.tgz'''<br />
|- bgcolor="ffdead"<br />
! Filenames || Comment<br />
|- <br />
| LFI_SkyMap_0??_0016_coswin_DX12_full_regnoise.fits || Low-resolution maps. Full mission coverage.<br />
|- <br />
| LFI_SkyMap_0??_0016_coswin_DX12_Corrected_full_regnoise.fits || Low-resolution maps BandPass Corrected. Full mission coverage. Corrected for the BandPass.<br />
|- <br />
| LFI_SkyMap_0??_0016_coswin_DX12_s1-s3-s5-s6-s7-s8_regnoise.fits || Low-resolution maps. Full mission coverage, excluding Surveys 2 and 4. <br />
|- <br />
| LFI_SkyMap_0??_0016_coswin_DX12_Corrected_s1-s3-s5-s6-s7-s8_regnoise.fits || Low-resolution maps. Full mission coverage, excluding Surveys 2 and 4. Corrected for the BandPass.<br />
|- <br />
| offset_covmat_toast_nside64T16_coswin_025sec_??GHz_DX12_full_bin.dat || Low-resolution noise covariance matrices. Regularization noise added. Format: C unformatted.<br />
|- <br />
| offset_covmat_toast_nside64T16_coswin_025sec_??GHz_DX12_s1-s3-s5-s6-s7-s8_bin.dat || Low-resolution noise covariance matrices. Regularization noise added. Format: C unformatted.<br />
|- <br />
| covmat_toast_nside64T16_coswin_025sec_??GHz_DX12_full_bin.dat || Low-resolution noise covariance matrices. No regularization noise added. Format: C unformatted.<br />
|- <br />
| covmat_toast_nside64T16_coswin_025sec_??GHz_DX12_s1-s3-s5-s6-s7-s8_bin.dat || Low-resolution noise covariance matrices. No regularization noise added. Format: C unformatted.<br />
|- <br />
|}<br />
<br />
<br />
<br />
The low-resolution data set can currently be utilized efficiently only at resolution <i>N</i><sub>side</sub> = 16, or lower. All the low-resolution data products are produced at this target resolution.<br />
===Low-resolution maps===<br />
A number of different schemes to obtain the low-resolution maps are discussed in {{BibCite|keskitalo2013}}. We chose to downgrade the maps using the inverse noise weighting, no changes on the procedure has been applyed to the 2018 release. This is discussed further in {{PlanckPapers|planck2013-p02}} {{PlanckPapers|planck2014-a07}}.<br />
====Inputs====<br />
We took the high-resolution maps described in [[Map-making LFI#Map-making|Map-making]] and [[Frequency Maps]], and the corresponding 3&times;3 matrices as an input for this analysis step.<br />
<br />
====Production====<br />
The high-resolution maps were downgraded to <i>N</i><sub>side</sub> = 16 using inverse noise weights (given by the 3&times;3 matrices), and subsequently the temperature part was smoothed with a symmetric Gaussian beam with FWHM = 440arcmin.<br />
<br />
===Noise covariance matrices===<br />
<br />
The statistical description of the residual noise in the maps is given in the form of a pixel-to-pixel noise covariance matrix (NCVM), as described in {{BibCite|keskitalo2013}}. <br />
<br />
====Inputs====<br />
<br />
The noise model was determined by three noise parameters: the white noise level &sigma;; slope; and knee frequency <i>f</i><sub>knee</sub>. We actually used three sets of noise parameters, one for the entire mission (noise parameters are listed in Table 1), and one for each sky survey (SS1 and SS2).<br />
<br />
We used the same pointing as in the noise Monte Carlo simulations. See the description in [[Map-making LFI#Noise Monte Carlo Simulation#Inputs|Noise Monte Carlo Simulation Inputs]].<br />
<br />
We used the gap files produced during the making of the flight maps to leave out samples that were flagged as bad for various reasons.<br />
<br />
====Production====<br />
<br />
The output of the NCVM module of MADAM mapmaker are inverse NCVMs. Since the inverse matrices are additive, we divided the computations into a number of small chunks to save computational resources. We first calculated one inverse NCVM per radiometer per survey at resolution <i>N</i><sub>side</sub>=32, and then combined these individual inverse matrices to form the actual inverse matrices. The mapmaking parameters were almost identical to the standard mapmaking runs. The differing parameter values are listed below:<br />
* baseline lengths were 0.25s for 30GHzand 1.0s for 44GHz, and 70GHz;<br />
* the calculations were performed at resolution <i>N</i><sub>side</sub> = 64;<br />
* no destriping mask was applied;<br />
* the horns were weighted optimally.<br />
<br />
To obtain the noise covariance from its inverse, the matrices are inverted using the eigen decomposition of a matrix. The monopole of the temperature map cannot be resolved by the mapmaker, and thus the matrix becomes singular. This ill-determined mode is left out of the analysis.<br />
<br />
Having calculated the eigen decomposition in the previous step, we can apply the same linear operators to modify the eigenvectors as were applied to the high-resolution maps while downgrading them. The eigenvectors are downgraded to <i>N</i><sub>side</sub> = 16 using inverse noise weights, and subsequently the temperature part is smoothed with a symmetric Gaussian beam with FWHM = 440arcmin.<br />
<br />
The final matrices are then recomposed from the original eigenvalues and modified eigenvectors.<br />
<br />
The low-resolution noise covariance matrices:<br />
* are C binary format files;<br />
* are organized in block form,<br />
<math><br />
\newcommand{\Re}{\mathrm{Re}\,}<br />
\newcommand{\pFq}[5]{{}_{#1}\mathrm{F}_{#2} \left( \genfrac{}{}{0pt}{}{#3}{#4} \bigg| {#5} \right)}<br />
</math><br />
<math><br />
\begin{align}<br />
\label{def:Block_form}<br />
\left (\begin{matrix}<br />
II & IQ & IU \\<br />
QI & QQ & QU \\<br />
UI & UQ & UU<br />
\end{matrix} \right);<br />
\end{align} <br />
</math><br />
<br />
* are in the HEALPix nested pixelisation scheme (with resolution is <i>N</i><sub>side</sub> = 16, and thus there are <i>N</i><sub>pix</sub> = 3072 pixels);<br />
* are in Galactic coordinates;<br />
* have K<sub>CMB</sub> units.<br />
<br />
==Half-ring jackknife noise maps==<br />
<br />
===Overview===<br />
In the 2018 release we follow the same procedure as in {{PlanckPapers|planck2014-a03||Planck-2015-A03}} in order to estimate the noise directly at the map level and in the angular power spectra.<br />
<br />
Briefly, instead of using the full time-ordered data as described above, we produced two sets of maps using either only the first half of each pointing period (map named <b>j</b><sub>1</sub> below) or only the second half of each pointing period (map named <b>j</b><sub>2</sub>). At each pixel <i>p</i>, these half-ring jackknife maps <b>j</b><sub>1</sub> and <b>j</b><sub>2</sub> contain the same sky signal, since they result from the same scanning pattern on the sky. However, because of instrumental noise, the maps <b>j</b><sub>1</sub> and <b>j</b><sub>2</sub> are not identical.<br />
<br />
We estimated the noise level in each map <b>m</b> made using the full (ring) data, by constructing a half-ring difference map<br />
<br />
<math>\mathbf{n_{m}}(p) = [ \mathbf{j_1}(p) - \mathbf{j_2}(p)] \ / \ \mathbf{w_{\rm hit}}(p)\,,</math><br />
<br />
with weights<br />
<br />
<math>\mathbf{w_{hit}}(p) = \sqrt{ \mathbf{hit_{full}}(p) \left[ \frac{1}{\mathbf{hit_1}(p)} +<br />
\frac{1}{\mathbf{hit_2}(p)} \right]}\,</math>.<br />
<br />
Here <b>hit</b><sub>full</sub>(<i>p</i>) = <b>hit</b><sub>1</sub>(<i>p</i>) + <b>hit</b><sub>2</sub>(<i>p</i>)<br />
is the hit count at pixel <i>p</i> in the full map <b>m</b>, while <b>hit</b><sub>1</sub> and <b>hit</b><sub>2</sub> are the hit counts of <b>j</b><sub>1</sub> and <b>j</b><sub>2</sub>, respectively. The weight factor <b>w</b><sub>hit</sub>(<i>p</i>) is equal to 2 only in those pixels where <b>hit</b><sub>1</sub>(<i>p</i>) = <b>hit</b><sub>2</sub>(<i>p</i>) . In a typical pixel, <b>hit</b><sub>1</sub>(<i>p</i>) will differ slightly from<br />
<b>hit</b><sub>2</sub>(<i>p</i>) and hence the weight factor is <b>w</b><sub>hit</sub>(<i>p</i>)>2.<br />
<br />
The half-ring difference maps <b>n</b><sub>m</sub> are the most direct measure of the noise in the actual maps. The other noise estimates (NCVM and noise Monte Carlo) rely on specific modelling of the noise and this modelling can be validated by comparing to the half-ring difference maps. However, the half-ring difference maps can only capture the noise that varies faster than half of the duration of the pointing period, i.e., the noise whose frequency is approximately <i>f</i> > 1/20min = 0.85mHz.<br />
<br />
We calculated the noise maps <b>n</b><sub>m</sub>, from half-ring "jackknife" maps for temperature (<i>I</i>) and polarization (<i>Q</i> and <i>U</i>) and as a first quality check of the maps (and as one of the tests of the whole data processing pipeline up to the map level) tested both numerically and visually that these noise maps divided pixel-by-pixel by the square root of the white noise covariance maps were approximately Gaussian with variance near to unity. Temperature noise maps for the nominal survey and for the first and second sky surveys are shown in the next subsection. Furthermore we calculated from the noise maps the temperature and polarization (E and B mode) auto-correlation and cross-correlation noise angular power spectra using HEALPix anafast and compared to these the results from the white noise covariance matrices and from the noise Monte Carlo simulations. A similar comparison was made between downgraded half-ring noise maps, downgraded noise Monte Carlo maps, and the low-resolution noise covariance maps. Detailed results are presented in {{PlanckPapers|planck2016-l02}}.<br />
<br />
===Comparison of noise estimates using Half-Ring===<br />
<br />
Here we compare noise angular power spectra estimated from half-ring difference maps (red), white noise covariance maps (black dash-dotted lines), and 100 full noise Monte Carlo simulations (grey band showing range for 16th and 84th quantiles of noise simulations, and the black solid lines giving the median, i.e., 50th quantile, of distributions). See the next section for details of noise Monte Carlo simulations. From top to botto we show ''TT'', ''EE'' and ''BB'' power spectra for 30 GHz (left), 44 GHz (centre), and 70 GHz (right). Half-ring spectra are binned with <math>\mathbf{\Delta}l = 25 </math> for <math> l \mathbf{\geq} 75 </math>.<br />
<br />
[[File:test_ffp10.png|thumb|800px|center|<b>Consistency Check</b>]]<br />
<br />
Below the null-tests comparing power spectra from survey differences to those from teh half-ring maps are showed. Difefrences are: left, Survey 1 - Survey 2; Middle , Survey 1- Survey 3; and right, Survey 1 - Survey4. these are for 30 GHz (top), 44 GHz (middle), and 70 GHz (bottom), for both ''TT'' and ''EE'' power spectra. There is a significant improvement in Surve1 - Survey 2 and Survey 1 - Survey 4 at 30 GHz, especially in ''EE''. See {{PlanckPapers|planck2016-l02}} for further details.<br />
<br />
[[File:nullhr1517.png|thumb|800px|center|<b>Null Test</b>]]<br />
<br />
<br />
====High-ell average noise relative to white noise estimate====<br />
<br />
The figure below is the same as the previous figures, but here the noise comparison is made from the high &#8467; tails of the angular power spectra, where the white noise dominates. We have taken the average of <i>C</i><sub>&#8467;</sub> from multipoles between 1150 and 1800 for both temperature and polarization and tehn comparing with the WNCVM. As already shown in previous releases, there is still an excess of 1/f noise, meaning tha both the real data and the noise MCs predict slightly larger noise than the WNCVM. It is important to note that such noise excess is reduced considerably with respect to the 2015 release.<br />
<br />
[[File:high.png|thumb|800px|center|<b>Ratio at high multipoles</b>]]<br />
<br />
==Noise Monte Carlo simulations==<br />
<br />
===Overview===<br />
Calculating and handling full pixel-to-pixel noise covariance matrices for Planck maps if feasible only at low resolution.<br />
To support the analysis of high-resolution maps, a Monte Carlo set of noise maps were produced. These maps were produced from noise timelines using the same map-making procedure as for the flight data. In the noise Monte Carlo it was possible to follow exactly the mapmaking procedure used for the flight maps, whereas for the calculation of noise covariance matrices some approximations had to be made.<br />
Such noise Monte Carlos were produced at two levels of the analysis: (1) LFI Monte Carlo (MC) as part of the LFI data processing procedure; and (2) Full Focal Plane (FFP) Monte Carlos as part of the joint HFI/LFI data processing. This page describes the LFI noise MCs. For the FFP MC, see [[HL-sims]] and [[Simulation data]].<br />
<br />
===Inputs===<br />
The noise MC uses a three-parameter noise model, consisting of white noise level (&sigma;), slope, and knee frequency (<i>f</i><sub>knee</sub>)). Here the noise consists of white noise and correlated 1/<i>f</i> noise, with a power spectrum<br />
<br />
:<math> P(f) = \frac{2\sigma^2}{f_\mathrm{sample}}\left(\frac{f}{f_\mathrm{knee}}\right)^\mathrm{slope} </math>,<br />
<br />
where <i>f</i><sub>sample</sub> is the sampling frequency of the instrument. The noise parameters were determined separately for each radiometer, as described in the section [[TOI processing LFI#Noise| Noise]] above, assuming they stayed constant over the mission. <br />
<br />
The detector pointing was reconstructed from satellite pointing information, focal-plane geometry, pointing correction (tilt angle), and sample timing, using Level-S simulation software. The same pointing solution (two focal planes) was used as for the LFI flight maps. Due to numerical accuracy, the detector pointing in the noise MC was not exactly the same as for the flight maps, so some data samples (of the order of one in a thousand) whose pointing was near the pixel boundary ended up assigned to the neighbouring pixel. During mapmaking from the flight data, a "gap file" was produced to represent the samples that were omitted from mapmaking due to various flags. This gap file was used in the noise MC instead of the full set of flags. The flight mapmaking procedure used destriping masks to prevent regions of strong signal gradients from contributing to the noise baseline solution. These same destriping masks (one for each frequency channel) were used for the noise MC.<br />
<br />
===Production===<br />
The noise was generated internally in the Madam mapmaking code using a stochastic differential equation (SDE) method, to avoid time-consuming writing and reading of noise timelines to and from disk. Noise for each pointing period was generated separately, using a double-precision random number seed constructed from the realization number, radiometer number, and the pointing period number; this allowed for regeneration of the same noise realization when needed. White noise and 1/<i>f</i> noise were generated separately. <br />
<br />
The same mapmaking code (Madam) with the same parameter settings was used for the noise MC as for the flight maps.<br />
In addition to the destriped maps from the full noise (output maps), binned maps from just the white noise (binned white noise maps) were produced; they represent the white noise part of the output maps. The difference between these two maps represents the residual correlated noise in the output map. The maps were made at HEALPix resolution <i>N</i><sub>side</sub> = 1024 for all LFI frequency channels and also at HEALPix resolution <i>N</i><sub>side</sub> = 2048 for the 70 GHz channel.<br />
For low-resolution analysis, these maps were downgraded (and the temperature part was smoothed) to <i>N</i><sub>side</sub> = 32 and <i>N</i><sub>side</sub> = 16.<br />
<br />
In addition to frequency maps for the nominal survey, also single-survey and 70 GHz horn-pair maps were produced in the noise MC. For each case 102-1026 realizations were produced.<br />
<br />
===Usage===<br />
<br />
These noise Monte Carlo maps were used for a number of purposes in LFI data analysis. They were compared to the low-resolution noise covariance matrices, generated for the same noise model, in order to reveal the impact of the approximations in the noise covariance matrix calculation. They were compared to the half-ring noise maps to see how well the noise model matches the noise in the flight maps (noting, however, that the half-ring noise maps misrepresent the lowest noise frequencies in the flight maps, and contain some effects from the sky signal). They were also used in power spectrum estimation and non-Gaussianity estimation.<br />
<br />
===Examples===<br />
<br />
As an example, we show below images of the first realization of the 70GHz frequency map noise for the nominal survey. The images are in the order: destriped full noise; binned white noise; and residual correlated noise. Note that it is difficult to see any difference between the first two images, since the residual correlated noise is more than an order of magnitude below the white noise level. The units here are K<sub>CMB</sub>. <br />
<br />
<br />
<br />
[[File:LFI_4_5_5_4_madam_mask_1sec_DB10_1_noise_70GHz_all_DX9delta_nom_1024outmap.00000.gif|thumb|800px|center|<b>Destriped full noise.</b>]]<br />
[[File:LFI_4_5_5_4_madam_mask_1sec_DB10_1_white_70GHz_all_DX9delta_nom_1024binmap.00000.gif|thumb|800px|center|<b>Binned white noise.</b>]]<br />
[[File:LFI_4_5_5_4_madam_mask_1sec_DB10_1_rcnoise_70GHz_all_DX9delta_nom_1024map.00000.gif|thumb|800px|center|<b>Residual correlated noise.</b>]]<br />
<br />
<br />
The following two images show the statistics of the angular power spectra of 101 realizations of the 70 GHz frequency map noise for the nominal survey. The thick black line shows the median <i>C</i><sub>&#8467;</sub>, while the green line the mean <i>C</i><sub>&#8467;</sub>. Thin black lines show the minimum, 16th percentile, 84th percentile, and the maximum <i>C</i><sub>&#8467;</sub>. The red line is the 102nd realization. The first plot is for the full noise in the output map, while the second plot is for the residual correlated noise.<br />
<br />
[[File:LFI_4_5_5_4_cl_TT_stat_noisemc101_1sec_70GHz_all_DX9delta_nom.png|thumb|800px|center|<b>Full noise.</b>]]<br />
[[File:LFI_4_5_5_4_cl_TT_stat_rcnoisemc101_1sec_70GHz_all_DX9delta_nom.png|thumb|800px|center|<b>Residual correlated noise.</b>]]<br />
<br />
==References==<br />
<br />
<br />
<References /><br />
<br />
<br />
<br />
<br />
[[Category:LFI data processing|004]]</div>Azaccheihttps://wiki.cosmos.esa.int/planck-legacy-archive/index.php?title=Map-making_LFI&diff=14124Map-making LFI2018-07-06T15:01:41Z<p>Azacchei: /* Low-resolution maps and noise covariance matrices */</p>
<hr />
<div>==Mapmaking==<br />
The inputs to the mapmaking procedure consist of the calibrated timelines, along with the corresponding pointing information.<br />
The main output consists of temperature and polarization maps. <br />
An important part of the mapmaking step is the removal of correlated 1/<i>f</i> noise.<br />
<br />
LFI maps were constructed with the MADAM mapmaking code, version 3.7.4.<br />
The code is based on a generalized destriping technique, where the correlated noise component is modelled as a sequence of constant offset "baselines". <br />
The baseline solution is constrained by a noise filter.<br />
As auxiliary information, the code produces a hit-count map and a white noise covariance matrix.<br />
No beam information is used, with the signal being simply assigned to the pixel where the centre of the beam falls.<br />
<br />
The chosen baseline length was 1s for the 44GHz and 70GHz maps, 0.25s for the 30GHz map. This gives good noise removal,<br />
without being computationally burdensome.<br />
The noise filter was built according to the noise parameters (see noise section).<br />
Flagged samples were excluded from the analysis. The Galaxy region was masked out in the destriping phase, to reduce errors arising from strong signal gradients. Radiometers were combined according to the horn-uniform weighting scheme to minimize systematics. The polarization component was included in the analysis and is part of this release.<br />
A detailed description of the mapmaking procedure is given in {{PlanckPapers|planck2013-p02}}, {{PlanckPapers|planck2014-a03}}, {{PlanckPapers|planck2014-a07}} no relevant changes has been applyed in the 2018 release. See also the section on [[Frequency Maps]].<br />
<br />
The maps are in HEALPix format, at resolution <i>N</i><sub>side</sub>=1024 for all frequencies with an additional map at <i>N</i><sub>side</sub>=2048 for the LFI 70GHz channel, in the nested pixelization scheme.<br />
Unobserved pixels are marked by a special value.<br />
<br />
The released maps are in Galactic coordinates.<br />
The conversion between ecliptic and Galactic coordinates is described by the rotation matrix<br />
<math><br />
\newcommand{\Re}{\mathrm{Re}\,}<br />
\newcommand{\pFq}[5]{{}_{#1}\mathrm{F}_{#2} \left( \genfrac{}{}{0pt}{}{#3}{#4} \bigg| {#5} \right)}<br />
</math><br />
<br />
:<math> <br />
\begin{align}<br />
\label{def:Rot_matrix}<br />
\left (\begin{matrix}<br />
-0.054882486 & 0.494116468 & -0.867661702\\ <br />
-0.993821033 & -0.110993846 & -0.000346354\\ <br />
-0.096476249 & 0.86228144 & 0.497154957 <br />
\end{matrix} \right).<br />
\end{align} <br />
</math> <br />
The conversion was applied to the input pointing data, prior to the construction of the map.<br />
<br />
==Low-resolution maps and noise covariance matrices==<br />
<br />
To fully exploit the information contained in the large-scale structure of the microwave sky, pixel-pixel covariances are needed in the maximum likelihood estimation of the CMB power spectrum. However, full covariance matrices are impossible to employ at the native map resolution due to resource limitations. A low-resolution data set is therefore required for the low-&#8467; analysis. This data set has been packed into three different files, one per frequency, called "LFI_NoiseCovMat_0??_0016_R3.00.tgz", that can be downloaded from the Cosmology section of the Planck Legacy Archive. <br />
They consist of low-resolution maps, and descriptions of residual noise present in those maps given by pixel-pixel noise covariance matrices (NCVMs).<br />
Note the in the 2018 release the Low-resolution maps full mission coverage, excluding Surveys 2 and 4 has not been used. We release them for crosschecking purposes with respect 2015 release.<br />
<br />
{| border="1" cellpadding="3" cellspacing="0" align="center" style="text-align:left" width=800px<br />
|+ Contents of '''LFI_NoiseCovMat_0??_0016_R3.00.tgz'''<br />
|- bgcolor="ffdead"<br />
! Filenames || Comment<br />
|- <br />
| LFI_SkyMap_0??_0016_coswin_DX12_full_regnoise.fits || Low-resolution maps. Full mission coverage.<br />
|- <br />
| LFI_SkyMap_0??_0016_coswin_DX12_Corrected_full_regnoise.fits || Low-resolution maps BandPass Corrected. Full mission coverage. Corrected for the BandPass.<br />
|- <br />
| LFI_SkyMap_0??_0016_coswin_DX12_s1-s3-s5-s6-s7-s8_regnoise.fits || Low-resolution maps. Full mission coverage, excluding Surveys 2 and 4. <br />
|- <br />
| LFI_SkyMap_0??_0016_coswin_DX12_Corrected_s1-s3-s5-s6-s7-s8_regnoise.fits || Low-resolution maps. Full mission coverage, excluding Surveys 2 and 4. Corrected for the BandPass.<br />
|- <br />
| offset_covmat_toast_nside64T16_coswin_025sec_??GHz_DX12_full_bin.dat || Low-resolution noise covariance matrices. Regularization noise added. Format: C unformatted.<br />
|- <br />
| offset_covmat_toast_nside64T16_coswin_025sec_??GHz_DX12_s1-s3-s5-s6-s7-s8_bin.dat || Low-resolution noise covariance matrices. Regularization noise added. Format: C unformatted.<br />
|- <br />
| covmat_toast_nside64T16_coswin_025sec_??GHz_DX12_full_bin.dat || Low-resolution noise covariance matrices. No regularization noise added. Format: C unformatted.<br />
|- <br />
| covmat_toast_nside64T16_coswin_025sec_??GHz_DX12_s1-s3-s5-s6-s7-s8_bin.dat || Low-resolution noise covariance matrices. No regularization noise added. Format: C unformatted.<br />
|- <br />
|}<br />
<br />
<br />
<br />
The low-resolution data set can currently be utilized efficiently only at resolution <i>N</i><sub>side</sub> = 16, or lower. All the low-resolution data products are produced at this target resolution.<br />
===Low-resolution maps===<br />
A number of different schemes to obtain the low-resolution maps are discussed in {{BibCite|keskitalo2013}}. We chose to downgrade the maps using the inverse noise weighting, no changes on the procedure has been applyed to the 2018 release. This is discussed further in {{PlanckPapers|planck2013-p02}} {{PlanckPapers|planck2014-a07}}.<br />
====Inputs====<br />
We took the high-resolution maps described in [[Map-making LFI#Map-making|Map-making]] and [[Frequency Maps]], and the corresponding 3&times;3 matrices as an input for this analysis step.<br />
<br />
====Production====<br />
The high-resolution maps were downgraded to <i>N</i><sub>side</sub> = 16 using inverse noise weights (given by the 3&times;3 matrices), and subsequently the temperature part was smoothed with a symmetric Gaussian beam with FWHM = 440arcmin.<br />
<br />
===Noise covariance matrices===<br />
<br />
The statistical description of the residual noise in the maps is given in the form of a pixel-to-pixel noise covariance matrix (NCVM), as described in {{BibCite|keskitalo2013}}. <br />
<br />
====Inputs====<br />
<br />
The noise model was determined by three noise parameters: the white noise level &sigma;; slope; and knee frequency <i>f</i><sub>knee</sub>. We actually used three sets of noise parameters, one for the entire mission (noise parameters are listed in Table 1), and one for each sky survey (SS1 and SS2).<br />
<br />
We used the same pointing as in the noise Monte Carlo simulations. See the description in [[Map-making LFI#Noise Monte Carlo Simulation#Inputs|Noise Monte Carlo Simulation Inputs]].<br />
<br />
We used the gap files produced during the making of the flight maps to leave out samples that were flagged as bad for various reasons.<br />
<br />
====Production====<br />
<br />
The output of the NCVM module of MADAM mapmaker are inverse NCVMs. Since the inverse matrices are additive, we divided the computations into a number of small chunks to save computational resources. We first calculated one inverse NCVM per radiometer per survey at resolution <i>N</i><sub>side</sub>=32, and then combined these individual inverse matrices to form the actual inverse matrices. The mapmaking parameters were almost identical to the standard mapmaking runs. The differing parameter values are listed below:<br />
* baseline lengths were 0.25s for 30GHzand 1.0s for 44GHz, and 70GHz;<br />
* the calculations were performed at resolution <i>N</i><sub>side</sub> = 64;<br />
* no destriping mask was applied;<br />
* the horns were weighted optimally.<br />
<br />
To obtain the noise covariance from its inverse, the matrices are inverted using the eigen decomposition of a matrix. The monopole of the temperature map cannot be resolved by the mapmaker, and thus the matrix becomes singular. This ill-determined mode is left out of the analysis.<br />
<br />
Having calculated the eigen decomposition in the previous step, we can apply the same linear operators to modify the eigenvectors as were applied to the high-resolution maps while downgrading them. The eigenvectors are downgraded to <i>N</i><sub>side</sub> = 16 using inverse noise weights, and subsequently the temperature part is smoothed with a symmetric Gaussian beam with FWHM = 440arcmin.<br />
<br />
The final matrices are then recomposed from the original eigenvalues and modified eigenvectors.<br />
<br />
The low-resolution noise covariance matrices:<br />
* are C binary format files;<br />
* are organized in block form,<br />
<math><br />
\newcommand{\Re}{\mathrm{Re}\,}<br />
\newcommand{\pFq}[5]{{}_{#1}\mathrm{F}_{#2} \left( \genfrac{}{}{0pt}{}{#3}{#4} \bigg| {#5} \right)}<br />
</math><br />
<math><br />
\begin{align}<br />
\label{def:Block_form}<br />
\left (\begin{matrix}<br />
II & IQ & IU \\<br />
QI & QQ & QU \\<br />
UI & UQ & UU<br />
\end{matrix} \right);<br />
\end{align} <br />
</math><br />
<br />
* are in the HEALPix nested pixelisation scheme (with resolution is <i>N</i><sub>side</sub> = 16, and thus there are <i>N</i><sub>pix</sub> = 3072 pixels);<br />
* are in Galactic coordinates;<br />
* have K<sub>CMB</sub> units.<br />
<br />
==Half-ring jackknife noise maps==<br />
<br />
===Overview===<br />
In the 2018 release we follow the same procedure as in {{PlanckPapers|planck2014-a03||Planck-2015-A03}} in order to estimate the noise directly at the map level and in the angular power spectra.<br />
<br />
Briefly, instead of using the full time-ordered data as described above, we produced two sets of maps using either only the first half of each pointing period (map named <b>j</b><sub>1</sub> below) or only the second half of each pointing period (map named <b>j</b><sub>2</sub>). At each pixel <i>p</i>, these half-ring jackknife maps <b>j</b><sub>1</sub> and <b>j</b><sub>2</sub> contain the same sky signal, since they result from the same scanning pattern on the sky. However, because of instrumental noise, the maps <b>j</b><sub>1</sub> and <b>j</b><sub>2</sub> are not identical.<br />
<br />
We estimated the noise level in each map <b>m</b> made using the full (ring) data, by constructing a half-ring difference map<br />
<br />
<math>\mathbf{n_{m}}(p) = [ \mathbf{j_1}(p) - \mathbf{j_2}(p)] \ / \ \mathbf{w_{\rm hit}}(p)\,,</math><br />
<br />
with weights<br />
<br />
<math>\mathbf{w_{hit}}(p) = \sqrt{ \mathbf{hit_{full}}(p) \left[ \frac{1}{\mathbf{hit_1}(p)} +<br />
\frac{1}{\mathbf{hit_2}(p)} \right]}\,</math>.<br />
<br />
Here <b>hit</b><sub>full</sub>(<i>p</i>) = <b>hit</b><sub>1</sub>(<i>p</i>) + <b>hit</b><sub>2</sub>(<i>p</i>)<br />
is the hit count at pixel <i>p</i> in the full map <b>m</b>, while <b>hit</b><sub>1</sub> and <b>hit</b><sub>2</sub> are the hit counts of <b>j</b><sub>1</sub> and <b>j</b><sub>2</sub>, respectively. The weight factor <b>w</b><sub>hit</sub>(<i>p</i>) is equal to 2 only in those pixels where <b>hit</b><sub>1</sub>(<i>p</i>) = <b>hit</b><sub>2</sub>(<i>p</i>) . In a typical pixel, <b>hit</b><sub>1</sub>(<i>p</i>) will differ slightly from<br />
<b>hit</b><sub>2</sub>(<i>p</i>) and hence the weight factor is <b>w</b><sub>hit</sub>(<i>p</i>)>2.<br />
<br />
The half-ring difference maps <b>n</b><sub>m</sub> are the most direct measure of the noise in the actual maps. The other noise estimates (NCVM and noise Monte Carlo) rely on specific modelling of the noise and this modelling can be validated by comparing to the half-ring difference maps. However, the half-ring difference maps can only capture the noise that varies faster than half of the duration of the pointing period, i.e., the noise whose frequency is approximately <i>f</i> > 1/20min = 0.85mHz.<br />
<br />
We calculated the noise maps <b>n</b><sub>m</sub>, from half-ring "jackknife" maps for temperature (<i>I</i>) and polarization (<i>Q</i> and <i>U</i>) and as a first quality check of the maps (and as one of the tests of the whole data processing pipeline up to the map level) tested both numerically and visually that these noise maps divided pixel-by-pixel by the square root of the white noise covariance maps were approximately Gaussian with variance near to unity. Temperature noise maps for the nominal survey and for the first and second sky surveys are shown in the next subsection. Furthermore we calculated from the noise maps the temperature and polarization (E and B mode) auto-correlation and cross-correlation noise angular power spectra using HEALPix anafast and compared to these the results from the white noise covariance matrices and from the noise Monte Carlo simulations. A similar comparison was made between downgraded half-ring noise maps, downgraded noise Monte Carlo maps, and the low-resolution noise covariance maps. Detailed results are presented in {{PlanckPapers|planck2016-l02}}.<br />
<br />
===Comparison of noise estimates using Half-Ring===<br />
<br />
Here we compare noise angular power spectra estimated from half-ring difference maps (red), white noise covariance maps (black dash-dotted lines), and 100 full noise Monte Carlo simulations (grey band showing range for 16th and 84th quantiles of noise simulations, and the black solid lines giving the median, i.e., 50th quantile, of distributions). See the next section for details of noise Monte Carlo simulations. From top to botto we show ''TT'', ''EE'' and ''BB'' power spectra for 30 GHz (left), 44 GHz (centre), and 70 GHz (right). Half-ring spectra are binned with <math>\mathbf{\Delta}l = 25 </math> for <math> l \mathbf{\geq} 75 </math>.<br />
<br />
[[File:test_ffp10.png|thumb|800px|center|<b>Consistency Check</b>]]<br />
<br />
Below the null-tests comparing power spectra from survey differences to those from teh half-ring maps are showed. Difefrences are: left, Survey 1 - Survey 2; Middle , Survey 1- Survey 3; and right, Survey 1 - Survey4. these are for 30 GHz (top), 44 GHz (middle), and 70 GHz (bottom), for both ''TT'' and ''EE'' power spectra. There is a significant improvement in Surve1 - Survey 2 and Survey 1 - Survey 4 at 30 GHz, especially in ''EE''. See {{PlanckPapers|planck2016-l02}} for further details.<br />
<br />
[[File:nullhr1517.png|thumb|800px|center|<b>Null Test</b>]]<br />
<br />
<br />
====High-ell average noise relative to white noise estimate====<br />
<br />
The figure below is the same as the previous figures, but here the noise comparison is made from the high &#8467; tails of the angular power spectra, where the white noise dominates. We have taken the average of <i>C</i><sub>&#8467;</sub> from multipoles between 1150 and 1800 for both temperature and polarization and tehn comparing with the WNCVM. As already shown in previous releases, there is still an excess of 1/f noise, meaning tha both the real data and the noise MCs predict slightly larger noise than the WNCVM. It is important to note that such noise excess is reduced considerably with respect to the 2015 release.<br />
<br />
[[File:high.png|thumb|800px|center|<b>Ratio at high multipoles</b>]]<br />
<br />
==Noise Monte Carlo simulations==<br />
<br />
===Overview===<br />
Calculating and handling full pixel-to-pixel noise covariance matrices for Planck maps if feasible only at low resolution.<br />
To support the analysis of high-resolution maps, a Monte Carlo set of noise maps were produced. These maps were produced from noise timelines using the same map-making procedure as for the flight data. In the noise Monte Carlo it was possible to follow exactly the mapmaking procedure used for the flight maps, whereas for the calculation of noise covariance matrices some approximations had to be made.<br />
Such noise Monte Carlos were produced at two levels of the analysis: (1) LFI Monte Carlo (MC) as part of the LFI data processing procedure; and (2) Full Focal Plane (FFP) Monte Carlos as part of the joint HFI/LFI data processing. This page describes the LFI noise MCs. For the FFP MC, see [[HL-sims]] and [[Simulation data]].<br />
<br />
===Inputs===<br />
The noise MC uses a three-parameter noise model, consisting of white noise level (&sigma;), slope, and knee frequency (<i>f</i><sub>knee</sub>)). Here the noise consists of white noise and correlated 1/<i>f</i> noise, with a power spectrum<br />
<br />
:<math> P(f) = \frac{2\sigma^2}{f_\mathrm{sample}}\left(\frac{f}{f_\mathrm{knee}}\right)^\mathrm{slope} </math>,<br />
<br />
where <i>f</i><sub>sample</sub> is the sampling frequency of the instrument. The noise parameters were determined separately for each radiometer, as described in the section [[TOI processing LFI#Noise| Noise]] above, assuming they stayed constant over the mission. <br />
<br />
The detector pointing was reconstructed from satellite pointing information, focal-plane geometry, pointing correction (tilt angle), and sample timing, using Level-S simulation software. The same pointing solution (two focal planes) was used as for the LFI flight maps. Due to numerical accuracy, the detector pointing in the noise MC was not exactly the same as for the flight maps, so some data samples (of the order of one in a thousand) whose pointing was near the pixel boundary ended up assigned to the neighbouring pixel. During mapmaking from the flight data, a "gap file" was produced to represent the samples that were omitted from mapmaking due to various flags. This gap file was used in the noise MC instead of the full set of flags. The flight mapmaking procedure used destriping masks to prevent regions of strong signal gradients from contributing to the noise baseline solution. These same destriping masks (one for each frequency channel) were used for the noise MC.<br />
<br />
===Production===<br />
The noise was generated internally in the Madam mapmaking code using a stochastic differential equation (SDE) method, to avoid time-consuming writing and reading of noise timelines to and from disk. Noise for each pointing period was generated separately, using a double-precision random number seed constructed from the realization number, radiometer number, and the pointing period number; this allowed for regeneration of the same noise realization when needed. White noise and 1/<i>f</i> noise were generated separately. <br />
<br />
The same mapmaking code (Madam) with the same parameter settings was used for the noise MC as for the flight maps.<br />
In addition to the destriped maps from the full noise (output maps), binned maps from just the white noise (binned white noise maps) were produced; they represent the white noise part of the output maps. The difference between these two maps represents the residual correlated noise in the output map. The maps were made at HEALPix resolution <i>N</i><sub>side</sub> = 1024 for all LFI frequency channels and also at HEALPix resolution <i>N</i><sub>side</sub> = 2048 for the 70 GHz channel.<br />
For low-resolution analysis, these maps were downgraded (and the temperature part was smoothed) to <i>N</i><sub>side</sub> = 32 and <i>N</i><sub>side</sub> = 16.<br />
<br />
In addition to frequency maps for the nominal survey, also single-survey and 70 GHz horn-pair maps were produced in the noise MC. For each case 102-1026 realizations were produced.<br />
<br />
===Usage===<br />
<br />
These noise Monte Carlo maps were used for a number of purposes in LFI data analysis. They were compared to the low-resolution noise covariance matrices, generated for the same noise model, in order to reveal the impact of the approximations in the noise covariance matrix calculation. They were compared to the half-ring noise maps to see how well the noise model matches the noise in the flight maps (noting, however, that the half-ring noise maps misrepresent the lowest noise frequencies in the flight maps, and contain some effects from the sky signal). They were also used in power spectrum estimation and non-Gaussianity estimation.<br />
<br />
===Examples===<br />
<br />
As an example, we show below images of the first realization of the 70GHz frequency map noise for the nominal survey. The images are in the order: destriped full noise; binned white noise; and residual correlated noise. Note that it is difficult to see any difference between the first two images, since the residual correlated noise is more than an order of magnitude below the white noise level. The units here are K<sub>CMB</sub>. <br />
<br />
<br />
<br />
[[File:LFI_4_5_5_4_madam_mask_1sec_DB10_1_noise_70GHz_all_DX9delta_nom_1024outmap.00000.gif|thumb|800px|center|<b>Destriped full noise.</b>]]<br />
[[File:LFI_4_5_5_4_madam_mask_1sec_DB10_1_white_70GHz_all_DX9delta_nom_1024binmap.00000.gif|thumb|800px|center|<b>Binned white noise.</b>]]<br />
[[File:LFI_4_5_5_4_madam_mask_1sec_DB10_1_rcnoise_70GHz_all_DX9delta_nom_1024map.00000.gif|thumb|800px|center|<b>Residual correlated noise.</b>]]<br />
<br />
<br />
The following two images show the statistics of the angular power spectra of 101 realizations of the 70 GHz frequency map noise for the nominal survey. The thick black line shows the median <i>C</i><sub>&#8467;</sub>, while the green line the mean <i>C</i><sub>&#8467;</sub>. Thin black lines show the minimum, 16th percentile, 84th percentile, and the maximum <i>C</i><sub>&#8467;</sub>. The red line is the 102nd realization. The first plot is for the full noise in the output map, while the second plot is for the residual correlated noise.<br />
<br />
[[File:LFI_4_5_5_4_cl_TT_stat_noisemc101_1sec_70GHz_all_DX9delta_nom.png|thumb|800px|center|<b>Full noise.</b>]]<br />
[[File:LFI_4_5_5_4_cl_TT_stat_rcnoisemc101_1sec_70GHz_all_DX9delta_nom.png|thumb|800px|center|<b>Residual correlated noise.</b>]]<br />
<br />
==References==<br />
<br />
<br />
<References /><br />
<br />
<br />
<br />
<br />
[[Category:LFI data processing|004]]</div>Azaccheihttps://wiki.cosmos.esa.int/planck-legacy-archive/index.php?title=The_RIMO&diff=14120The RIMO2018-07-06T14:32:45Z<p>Azacchei: /* File Names */</p>
<hr />
<div>{{DISPLAYTITLE:The 2018 instrument model}}<br />
== Overview ==<br />
<br />
The RIMO, or "Reduced Instrument Model" is a FITS file or a set of FITS files containing selected instrument characteristics that are needed by users who work with the released data products. It is described in detail in "The HFI and LFI RIMO Interface Control Documents" (see also {{PlanckPapers|planck2014-a03}} and {{PlanckPapers|planck2014-a08}}). There are two RIMOs, one for each instrument (the HFI RIMO consists of several parts), which follow the same overall structure, but differ in the details. <br />
<br />
The type of data in the RIMO can be of several forms.<br />
<br />
; Parameter : These are scalars, to give properties such as a noise level or a representative beam FWHM.<br />
; Vector or Table : These give, e.g., filter transmission profiles, noise power spectra, or beam window functions. When possible (specifically when they are of equal length, such as the noise power spectra), an effort is made to put them together into a table, otherwise they are given as separate vectors.<br />
; Image : These 2-D "flat" arrays give, e.g., the beam correlation matrices.<br />
<br />
The FITS file begins with the primary header, which contains some keywords that are mainly for internal use. The different types of data are written into different BINTABLE (for parameters and tables) or IMAGE (for 2-D arrays) extensions, as described below. <br />
<br />
<span style="color:#0000ee">Attn regarding HFI_RIMO:</span> For the HFI 2018 (legacy) release, which contains only maps, the RIMO contains only the merged bandpasses necessary to describe those maps; this is because the RIMO of a release contains information regarding the products of the release. In practice, for the this release, these bandpasses are a simple average of the bandpasses of the detectors used in each map (which can be found in RIMO of the 2015 release) without any weighting (i.e., SWBs have the same weight as PSBs). As a consequence, the next section describing the contents, applies almost exclusively to the LFI RIMO<br />
<br />
<br />
=== File Names ===<br />
<br />
; HFI 2018 RIMO: {{PLASingleFile|fileType=rimo|name=HFI_RIMO_R3.00.fits|link=HFI_RIMO_R3.00.fits}}<br />
; LFI 2018 RIMO: {{PLASingleFile|fileType=rimo|name=LFI_RIMO_R3.00.fits|link=LFI_RIMO_R3.31.fits}}<br />
<br />
== Detector-level parameter data (LFI only) ==<br />
<br />
The detector parameter data are stored in the form of a table giving the parameter values for each detector. The table columns (whose names are in ''BOLD ITALICS'') are as follows.<br />
<br />
; Bolometer name - ''DETECTOR'' : These are the detector names. For HFI they are of the form ''217-3'' for SWBs or ''100-3b'' for PSBs, and for LFI they are of the form 27M or 18S. There are 52 HFI detectors and 22 LFI detectors.<br />
<br />
; Focal plane geometry parameters - ''PHI_UV'', ''THETA_UV'', and ''PSI_UV'' : These parameters give the geometry of the focal plane, or the positions of the detectors in the focal plane in the Dxx reference frame. The angles that give the rotation of the beam pattern from a fiducial orientation (forward beam direction (<i>z</i>-axis) pointing along the telescope line of sight, with <i>y</i>-axis aligned with the nominal scan direction) to their positions in the focal plane. The fiducial position is that given by the Star Tracker. All angles are in radians. These parameters are derived from observations of bright planets; see [[Detector_pointing | Detector pointing]] for details.<br />
<br />
; Polarization parameters - ''PSI_POL'', ''EPSILON'' :These are the direction of maximum polarization (defined with the beam in the fiducial orientation described above, that is, before rotation onto the detector position), and the cross-polarization contamination (or leakage). These values are determined from ground-based measurements.<br />
<br />
; Beam parameters - ''FWHM'', ''ELLIPTICITY'', ''POSANG'' : These are the mean FWHM of the scanning beam (in arcmin), the beam ellipticity (no units), and the position angle of the beam major axis. The scanning beam is that recovered from the observation of bright planets. Details are in the [[Beams]] section.<br />
<br />
; Noise parameters - ''NET'' (LFI), ''NET_TOT'' (HFI), ''NET_WHT'' (HFI), ''NET_OOF'' (HFI), ''F_KNEE'', ''ALPHA'', ''F_MIN'' (LFI), ''F_MAX'' (LFI) : Three NETs are given: one determined from the total noise (rms of the noise timeline, excluding glitched data and other non-valid data); one determined from the white noise level of the noise amplitude spectrum; and the last determined from fitting a ''1/<i>f</i>'' noise spectrum, described by the function &sigma;<sup>2</sup>(1+(<i>f</i><sub>knee</sub>/<i>f</i>)<sup>&alpha;</sup>) to the noise <i>power</i> spectrum. In the latter, the ''F_KNEE'' and ''ALPHA'' parameters are the frequency where the ''1/<i>f</i>'' component meets the white noise level, and the slope of the former. Since this is defined in power, the slope is about twice the slope of the amplitude spectrum. The NETs are in units of K<sub>CMB</sub>.&radic;s for 30-353 GHz, and MJy sr<sup>-1</sup>.&radic;s for 545 and 857 GHz.<br />
<br />
; Detector sampling frequency - ''F_SAMP'' : This is self-explanatory. <br />
<br />
In the HFI RIMO, this table includes entries for the RTS bolometers (143-8 and 545-3), which are approximate or 0.00 when not evaluated.<br />
<br />
== Map-level parameter data (LFI only) ==<br />
<br />
The map-level data table contains the effective beam solid angle (total, as well as integrated out to different multiples of the beam FWHM) and noise information. It is written into a BINTABLE extension named ''MAP_PARAMS'', whose structure is different for HFI and LFI and is as follows. The noise description below is very simplified; a more complete rendition can be obtained from the half-ring maps. For characterization of systematic effects, the survey differences should be used.<br />
<br />
; ''FREQUENCY'' (String) : A 3-digit string giving the reference frequency in GHz, i.e., of the form "030".<br />
; ''FWHM'' (Real*8) : FWHM of a Gaussian beam having the same (total) solid angle, in arcmin.<br />
; ''NOISE'' (Real*8) : This is the average noise in K.s<sup>1/2</sup>.<br />
; ''CENTRALFREQ'' (Real*4) : This is the average central frequency in GHz.<br />
; ''FWHM_EFF'', ''FWHM_EFF_SIGMA'' (Real*4) : This is the average FWHM of the effective beam, in arcmin, and its dispersion.<br />
; ''ELLIPTICITY_EFF'', ''ELLIPTICITY_EFF_SIGMA'' (Real*4) : This is the average ellipticity and its dispersion.<br />
; ''SOLID_ANGLE_EFF'', ''SOLID_ANGLE_EFF_SIGMA'' (Real*4) : This is the average full beam solid angle, in arcmin<sup>2</sup>, and its dispersion.<br />
<br />
== Effective band transmission profiles ==<br />
<br />
The effective filter bandpasses are given in different BINTABLE extensions. The extension is named ''BANDPASS_{name}'', where ''name'' specifies the detector or the maps. For the latter, the bandpasses are a weighted average of the bandpasses of the detectors that are used to build the map, using the same weights that are used in the mapmaking. These merged bandpasses are given for the full channel maps (all detectors within each frequency channel) and for the PSBs only in each frequency channel for HFI. For details on the measurements and compilation of the bandpasses see {{PlanckPapers|planck2013-p03d}}. For details on the measurements and compilation of the LFI bandpasses see {{PlanckPapers|planck2014-a05||Planck-2015-A05}}. <br />
<br />
The bandpasses are given as 4-column tables containing the following elements.<br />
<br />
=== HFI ===<br />
<br />
; ''WAVENUMBER'' (Real*4) : The wavenumber in cm<sup>-1</sup>, with conversion to GHz being accomplished by multiplying by 10<sup>-7</sup>c [mks].<br />
; ''TRANSMISSION'' (Real*4) : The transmission (normalized to 1 at the maximum for HFI).<br />
; ''FLAG'' (Integer) : A flag indicating if the data point is an independent frequency data point (normally the case, "flag=0"), or an FTS instrument line shape (ILS)-interpolated data point ("flag=1"). In the latter case the frequency data have been over-sampled by about a factor of 10 to assist in CO component-separation efforts {{PlanckPapers|planck2013-p03d}}{{PlanckPapers|planck2013-p03a}}.<br />
<br />
Note that there is no "ERROR" column in this delivery. This is because the error given previously was simply a small statistical measurement error for each point and did not include other potentially more importantc (but not measured, and not measurable) systematic errors, which could affect the overall shape of the transmission profile.<br />
<br />
=== LFI ===<br />
<br />
; ''WAVENUMBER'' (Real*8) : The wavenumber in GHz. <br />
; ''TRANSMISSION'' (Real*8) : The transmission (normalized to have an integral of 1 for LFI).<br />
; ''UNCERTAINITY'' (Real*4) : The statistical <math>1\sigma</math> uncertainty for the transmission profile (not provided for LFI).<br />
; ''FLAG'' (Character) : a flag, not used now by the LFI.<br />
<br />
The number of rows will differ among the different extensions, but are the same, by construction, within each extension.<br />
<br />
== Beam window functions (LFI only) ==<br />
<br />
'''Please note that the HFI beam window functions are no longer delivered in a RIMO: see the [[Beam Window Functions | Beam_Window_Functions ]] section for the HFI version of these products.'''<br />
<br />
Beam window functions and associated error descriptions are written into a BINTABLE for each "detection unit", where "detection unit" consists of an auto- or a cross-product (for HFI only) of one (or two) frequency maps or detset maps used in the likelihood. They are explicitly listed below.<br />
<br />
* the three LFI frequency channels (auto-products only), producing three extensions, namely<br />
** 30, 44, 70;<br />
* the three LFI 70GHz detector pairs (auto-products only), producing three extensions, namely<br />
** 18-23, 19-22, 20-21.<br />
<br />
The extension names are of the form "BEAMWF_U1XU2", where "U1" and "U2" are one (possibly the same) detection unit from one of the main groups above (i.e., there are no cross-products between detsets and frequency channels, or between HFI and LFI). Each extension contains the following columns.<br />
; ''NOMINAL'' (HFI, Real*4) : The beam window function proper.<br />
; ''BL'' (LFI, Real*4) : The beam window function proper.<br />
; ''EIGEN_n'' (Real*4, <i>n</i>=1-5 for the HFI, <i>n</i>=1-4 for the LFI): The five/four corresponding error modes.<br />
<br />
The following keywords give further information, only for the HFI.<br />
; ''NMODES'' (Integer) : The number of EIGEN_* modes.<br />
; ''LMIN'' and ''LMAX'' (Integer) : The starting and ending (both included) multipoles of the vectors NOMINAL and EIGEN_* .<br />
; ''LMIN_EM'' and ''LMAX_EM'' (Integer) : These give the range of the valid samples of the EIGEN_* vectors. Here "LMAX_EM" is always less than or equal to "LMAX". On the range "LMAX_EM"+1 to "LMAX" the values of EIGEN_* are set to NaN, while the values of NOMINAL are a Gaussian extrapolation of the lower multipole window function, only provided for convenience.<br />
; ''CORRMAT'' (string) : The name of the extension containing the corresponding beam correlation matrix.<br />
<br />
Finally, also see the "COMMENT" of each header for more specific details.<br />
<br />
==Appendices==<br />
<br />
* [[UC_CC_Tables | Unit correction and color correction tables]]<br />
<br />
== Previous Releases: (2015) and (2013) Instrument Models ==<br />
<br />
<div class="toccolours mw-collapsible mw-collapsed" style="background-color: #FFDAB9;width:80%"><br />
'''The 2015 Instrument Model'''<br />
<div class="mw-collapsible-content"><br />
<br />
'' Overview ''<br />
<br />
The RIMO, or "Reduced Instrument Model" is a FITS file or a set of FITS files containing selected instrument characteristics that are needed by users who work with the released data products. It is described in detail in "The HFI and LFI RIMO Interface Control Documents" (see also {{PlanckPapers|planck2014-a03}} and {{PlanckPapers|planck2014-a08}}). There are two RIMOs, one for each instrument (the HFI RIMO consists of several parts), which follow the same overall structure, but differ in the details. The type of data in the RIMO can be of several forms.<br />
<br />
; Parameter : These are scalars, to give properties such as a noise level or a representative beam FWHM.<br />
; Vector or Table : These give, e.g., filter transmission profiles, noise power spectra, or beam window functions. When possible (specifically when they are of equal length, such as the noise power spectra), an effort is made to put them together into a table, otherwise they are given as separate vectors.<br />
; Image : These 2-D "flat" arrays give, e.g., the beam correlation matrices.<br />
<br />
The FITS file begins with the primary header, which contains some keywords that are mainly for internal use. The different types of data are written into different BINTABLE (for parameters and tables) or IMAGE (for 2-D arrays) extensions, as described below. <br />
<br />
The HFI-RIMO separates the beam window functions and associated data from the main set of parameters; this is because the beam window functions are delivered for two cases covering 100% and 75% of the sky, as described in detail below.<br />
<br />
''' File Names '''<br />
<br />
; HFI 2015 RIMO: {{PLASingleFile|fileType=rimo|name=HFI_RIMO_R2.00.fits|link=HFI_RIMO_R2.00.fits}}<br />
; LFI 2015 RIMO: {{PLASingleFile|fileType=rimo|name=LFI_RIMO_R2.50.fits|link=LFI_RIMO_R2.50.fits}}<br />
<br />
'' Detector-level parameter data ''<br />
<br />
The detector parameter data are stored in the form of a table giving the parameter values for each detector. The table columns (whose names are in ''BOLD ITALICS'') are as follows.<br />
<br />
; Bolometer name - ''DETECTOR'' : These are the detector names. For HFI they are of the form ''217-3'' for SWBs or ''100-3b'' for PSBs, and for LFI they are of the form 27M or 18S. There are 52 HFI detectors and 22 LFI detectors.<br />
<br />
; Focal plane geometry parameters - ''PHI_UV'', ''THETA_UV'', and ''PSI_UV'' : These parameters give the geometry of the focal plane, or the positions of the detectors in the focal plane in the Dxx reference frame. The angles that give the rotation of the beam pattern from a fiducial orientation (forward beam direction (<i>z</i>-axis) pointing along the telescope line of sight, with <i>y</i>-axis aligned with the nominal scan direction) to their positions in the focal plane. The fiducial position is that given by the Star Tracker. All angles are in radians. These parameters are derived from observations of bright planets; see [[Detector_pointing | Detector pointing]] for details.<br />
<br />
; Polarization parameters - ''PSI_POL'', ''EPSILON'' :These are the direction of maximum polarization (defined with the beam in the fiducial orientation described above, that is, before rotation onto the detector position), and the cross-polarization contamination (or leakage). These values are determined from ground-based measurements.<br />
<br />
; Beam parameters - ''FWHM'', ''ELLIPTICITY'', ''POSANG'' : These are the mean FWHM of the scanning beam (in arcmin), the beam ellipticity (no units), and the position angle of the beam major axis. The scanning beam is that recovered from the observation of bright planets. Details are in the [[Beams]] section.<br />
<br />
; Noise parameters - ''NET'' (LFI), ''NET_TOT'' (HFI), ''NET_WHT'' (HFI), ''NET_OOF'' (HFI), ''F_KNEE'', ''ALPHA'', ''F_MIN'' (LFI), ''F_MAX'' (LFI) : Three NETs are given: one determined from the total noise (rms of the noise timeline, excluding glitched data and other non-valid data); one determined from the white noise level of the noise amplitude spectrum; and the last determined from fitting a ''1/<i>f</i>'' noise spectrum, described by the function &sigma;<sup>2</sup>(1+(<i>f</i><sub>knee</sub>/<i>f</i>)<sup>&alpha;</sup>) to the noise <i>power</i> spectrum. In the latter, the ''F_KNEE'' and ''ALPHA'' parameters are the frequency where the ''1/<i>f</i>'' component meets the white noise level, and the slope of the former. Since this is defined in power, the slope is about twice the slope of the amplitude spectrum. The NETs are in units of K<sub>CMB</sub>.&radic;s for 30-353 GHz, and MJy sr<sup>-1</sup>.&radic;s for 545 and 857 GHz.<br />
<br />
; Detector sampling frequency - ''F_SAMP'' : This is self-explanatory. <br />
<br />
In the HFI RIMO, this table includes entries for the RTS bolometers (143-8 and 545-3), which are approximate or 0.00 when not evaluated.<br />
<br />
'' Map-level parameter data ''<br />
<br />
The map-level data table contains the effective beam solid angle (total and out to different multiples of the beamFWHM) and noise information. It is written into a BINTABLE extension named ''MAP_PARAMS'' whose structure is different for HFI and LFI and is as follows. The noise description below is very simplified; a more accurate rendition can be obtained from the half-ring maps. Regarding the characterization of systematics, the user should use the survey differences.<br />
<br />
''' HFI '''<br />
<br />
; ''FREQUENCY'' (String) : a 3-digit string giving the reference frequency in GHz, i.e., of the form ''217''<br />
; ''OMEGA_F'', ''OMEGA_F_ERR'' (Real*4) : the full beam solid angle and its uncertainty, in armin<sup>2</sup><br />
; ''OMEGA_1'', ''OMEGA_1_DISP'' (Real*4) : the beam solid angle out to 1FWHM, and its dispersion, in arcmin<sup>2</sup><br />
; ''OMEGA_2'', ''OMEGA_2_DISP'' (Real*4) : the beam solid angle out to 2FWHM, and its dispersion, in arcmin<sup>2</sup><br />
; ''FWHM'' (Real*4) : FWHM of a Gaussian beam having the same (total) solid angle, in armin<sup>2</sup>. This is the best value for source flux determination<br />
; ''FWHMGAUS'' (Real*4) : FWHM derived from best Gaussian fit to beam maps, in armin<sup>2</sup>. This is the best value for source identification<br />
; ''NOISE'' (Real*4) : This is the typical noise/valid observation sample as derived from the high-''l'' spectra of the half-ring maps, in the units of the corresponding map<br />
<br />
For the Omega columns, the 'DISP' (for ''dispersion'') column gives an estimate of the spatial variation as a function of position on the sky. This is the variation induced by combining the scanning beam determined from the planet observations with the scanning strategy, as described in [[Beams]].<br />
<br />
''' LFI '''<br />
<br />
; ''FREQUENCY'' (String) : a 3-digit string giving the reference frequency in GHz, i.e., of the form ''030, 044, 070''<br />
; ''FWHM'' (Real*8) : FWHM of a Gaussian beam having the same (total) solid angle, in arcmin<br />
; ''NOISE'' (Real*8) : This is the average noise in T<math>\cdot</math>s<sup>1/2</sup> <br />
; ''CENTRALFREQ'' (Real*4) : This is the average central frequency in GHz<br />
; ''FWHM_EFF'', ''FWHM_EFF_SIGMA'' (Real*4) : This is the average FWHM of the effective beam, in arcmin, and its dispersion<br />
; ''ELLIPTICITY_EFF'', ''ELLIPTICITY_EFF_SIGMA'' (Real*4) : This is the average ellipticity and its dispersion<br />
; ''SOLID_ANGLE_EFF'', ''SOLID_ANGLE_EFF_SIGMA'' (Real*4) : This is the average full beam solid angle, in arcmin<sup>2</sup>, and its dispersion<br />
<br />
'' Effective band transmission profiles ''<br />
<br />
The effective filter bandpasses are given in different BINTABLE extensions. The extension is named ''BANDPASS_{name}'', where ''name'' specifies the detector or the maps. For the latter, the bandpasses are a weighted average of the bandpasses of the detectors that are used to build the map, using the same weights that are used in the mapmaking. These merged bandpasses are given for the full channel maps (all detectors of the frequency channel) and for the PSBs only in each frequency channel for HFI. For details on the measurements and compilation of the bandpasses see {{PlanckPapers|planck2013-p03d}}. For details on the measurements and compilation of the LFI bandpasses see {{PlanckPapers|planck2014-a05||Planck-2015-A05}}. <br />
<br />
The bandpasses are given as 4-column tables containing:<br />
<br />
''' HFI '''<br />
<br />
; ''WAVENUMBER'' (Real*4) : the wavenumber in cm-1, conversion to GHz is accomplished by multiplying by <math>10^{-7}c</math> [mks].<br />
; ''TRANSMISSION'' (Real*4) : the transmission (normalized to 1 at the max for HFI)<br />
; ''ERROR'' (Real*4) : the statistical <math>1\sigma</math> uncertainty for the transmission profile.<br />
; ''FLAG'' (Integer) : a flag indicating if the data point is an independent frequency data point (nominally the case), or an FTS instrument line shape (ILS)-interpolated data point. The frequency data has been over-sampled by a factor of ~10 to assist in CO component separation efforts {{PlanckPapers|planck2013-p03d}}{{PlanckPapers|planck2013-p03a}}.<br />
<br />
The number of rows will differ among the different extensions, but are the same, by construction, within each extension. Tables with the unit conversion coefficients and color correction factors for the HFI detectors (and LFI in some instances), including uncertainty estimates based on the uncertainty of the HFI detector spectral response are given in [[UC_CC_Tables | this appendix]].<br />
<br />
''' LFI '''<br />
<br />
; ''WAVENUMBER'' (Real*8) : the wavenumber in GHz. <br />
; ''TRANSMISSION'' (Real*8) : the transmission (normalized to have an integral of 1 for LFI)<br />
; ''UNCERTAINITY'' (Real*4) : the statistical <math>1\sigma</math> uncertainty for the transmission profile (not provided for LFI)<br />
; ''FLAG'' (Character) : a flag, not used by now by the LFI<br />
<br />
The number of rows will differ among the different extensions, but are the same, by construction, within each extension.<br />
<br />
'' Detector noise spectra (Only HFI)''<br />
<br />
; HFI: these are the ring noise amplitude spectra averaged over about 5000 rings in order to give a representative spectrum. The spectra of all 50 valid bolometers are given in a single table. The spectra have a maximum frequency (Nyquist) of 90.18685Hz, also given the the ''F_NYQ'' keyword, and are built over 32768 points, giving a lower frequency of 2.75 mHz.<br />
<br />
<br />
The keyword ''F_NYQ'' gives the Nyquist frequency, and can be used together with the number of points in the spectrum to reconstruct the frequency scale. The BINTABLE has Ndetector columns by Npoints rows.<br />
<br />
<br />
'' Beam Window Functions ''<br />
<br />
Beam window functions and associated error descriptions are written into a BINTABLE for each ''detection unit'', where ''detection unit'' consists of an auto or a cross product (for HFI only) of one (or two) frequency maps or detset maps used in the likelihood. Here they are: <br />
<br />
; ''For the HFI'':<br />
* the 6 HFI frequency channels + 3 psb-only subsets, producing 45 extensions<br />
** 100, 143, 217, 353, 545, 857, 143p, 217p, 353p<br />
* 26 detsets, producing 351 extensions; the detsets used are, by frequency channel:<br />
** 100-DS1, 100-DS2,<br />
** 143-DS1, 143-DS2, 143-5, 143-6, 143-7,<br />
** 217-DS1, 217-DS2, 217-1, 217-2, 217-3, 217-4, <br />
** 353-DS1, 353-DS2, 353-1, 353-2, 353-7, 353-8,<br />
** 545-1, 545-2, 545-4,<br />
** 857-1, 857-2, 857-3, 857-4<br />
<br />
Note for HFI these (and also the associated covariance matrices) are given in separate files named ''HFI_RIMO-Beams-nnnpc_Rm.nn.fits'', where nnn is 100 or 075 and indicates the percentage (pc) of the sky included (see [[Frequency_Maps#Galactic_Plane_masks | Masks]] and [[Beams#Impact_of_sky_cut|Beams]] sections).<br />
<br />
; ''For the LFI'':<br />
* the 3 LFI frequency channels (auto- products only), producing 3 extensions<br />
** 30, 44, 70<br />
* the 3 LFI 70GHz detector pairs (auto- products only), producing 3 extensions<br />
** 18-23, 19-22, 20-21<br />
<br />
The extension names are of the form ''BEAMWF_U1XU2'' where U1 and U2 are one (possibly the same) detection unit from one of the main groups above (i.e. there are no cross products between detsets and frequency channels, or between HFI and LFI). Each extension contains the columns:<br />
; ''NOMINAL'' (HFI, Real*4) : the beam window function proper,<br />
; ''BL'' (LFI, Real*4) : the beam window function proper,<br />
; ''EIGEN_n'' (Real*4, n=1-5 for the HFI, n=1-4 for the LFI): the five/four corresponding error modes.<br />
<br />
and the following keywords give further information, only for the HFI:<br />
; ''NMODES'' (Integer) : the number of EIGEN_* modes,<br />
; ''LMIN'' and ''LMAX'' (Integer) : the starting and ending (both included) multipoles of the vectors NOMINAL and EIGEN_*<br />
; ''LMIN_EM'' and ''LMAX_EM'' (Integer) : that give the range of the valid samples of the EIGEN_* vectors. Here ''LMAX_EM'' is always less than or equal to ''LMAX''. On the range ''LMAX_EM''+1 to ''LMAX'' the values of EIGEN_* are set to NaN, while the values of NOMINAL only are a Gaussian extrapolation of the lower multipole window function, only provided for convenience.<br />
; ''CORRMAT'' (string) : the name of the extension containing the corresponding beam correlation matrix<br />
<br />
And finally see also the ''COMMENTs'' of each header for more specific details.<br />
<br />
'' Beam Correlation Matrix ''<br />
<br />
Two beam correlation matrices are given for the HFI, in two ''IMAGE'' extensions:<br />
; ''CORRBEAM_FREQ'' (Real*8) : for the frequency channels (21 units), 105x015 pixel matrix,<br />
; ''CORRBEAM_DSET'' (Real*8) : for the detsets (351 units), 1755x1755 pixel matrix <br />
Each is a symmetric matrix with 1-valued diagonal, made of NBEAMS*NBEAMS blocks, each block being NMODES*NMODES in size. The n$^{th}$ row- (and column-) block entry relates to the B(l) model whose name is indicated in ROWn = BEAMWF_U1XU2 keywords, and the corresponding eigenmodes are stored in a HDU of the same name. <br />
<br />
Each extension contains also the following keywords:<br />
; ''NDETS'' (Integer) : the number of detector units<br />
; ''NBEAMS'' (Integer) : the number of beams = NSETS * (NSETS+1) / 2<br />
; ''NMODES'' (Integer) : here 5<br />
; ''L_PLUS'' (Integer) : Eigenmode > 0 to break degeneracies<br />
; ''BLOCKn'' (string) : for n=1-NBEAMS, gives the name of the extension containing the beam WF and error eigenmodes for the nth block<br />
and some other ones for internal data checking and traceability<br />
<br />
No beam correlation matrices are produced by the LFI by now. And for HFI these, together with the beam window functions, are given in a file separate from the main RIMO (see subsection above).<br />
<br />
''Appendices''<br />
<br />
* [[UC_CC_Tables | Unit correction and color correction tables]]<br />
<br />
<br />
</div><br />
</div><br />
<br />
<div class="toccolours mw-collapsible mw-collapsed" style="background-color: #EEE8AA;width:80%"><br />
'''The 2013 Instrument Model'''<br />
<div class="mw-collapsible-content"><br />
<br />
'' Overview ''<br />
<br />
The RIMO, or ''Reduced Instrument Model'' is a FITS file containing selected instrument characteristics that are needed by users who work with the released data products. It is described in detail in ''The HFI and LFI RIMO ICD'' (ref). There will be two RIMOs, one for each instrument, which will follow the same overall structure, but will differ in the details. The type of data in the RIMO can be:<br />
<br />
; Parameter : namely scalars to give properties such as a noise level or a representative beam FWHM<br />
; Table : to give, e.g., filter transmission profiles or noise power spectra<br />
; Image : namely 2-D "flat" array, to give, e.g., the beam correlation matrices<br />
<br />
The FITS file begins with primary header that contains some keywords that mainly for internal use and no data. The different types of data are written into different BINTABLE (for parameters and tables) or IMAGE (for 2-D arrays) extensions, as described below. <br />
<br />
''' File Names '''<br />
<br />
; HFI: {{PLASingleFile|fileType=rimo|name=HFI_RIMO_R1.10.fits|link=HFI_RIMO_R1.10.fits}}<br />
; LFI: {{PLASingleFile|fileType=rimo|name=LFI_RIMO_R1.12.fits|link=LFI_RIMO_R1.12.fits}}<br />
<br />
<br />
<!--<br />
'' Detector-level parameter data ''<br />
<br />
There are no detector-level products in the first release.<br />
<br />
<br />
The detector parameter data are given in the form of a table giving the parameter values for each detector. The table columns (whose names are in ''BOLD ITALICS'') are:<br />
<br />
; Bolometer name - ''DETECTOR'' : These are the detector names. For HFI these will be of the form ''217-3'' for SWBs or ''100-3b'' for PSBs, and for LFI they will have the form 27M or 18S. There are 52 HFI detectors and 22 LFI detectors.<br />
<br />
; Focal plane geometry parameters - ''PHI_UV'', ''THETA_UV'', and ''PSI_UV'' : These parameters give the geometry of the focal plane, or the positions of the detectors in the focal plane. The angles that give the rotation of the beam pattern from a fiducial orientation (forward beam direction (z-axis) pointing along the telescope line of sight, with y-axis aligned with the nominal scan direction) to their positions in the focal plane. The fiducial position is that given by the Star Tracker. All angles are in radians. These parameters are derived from observations of bright planets; see [[Detector_pointing | Detector pointing]] for details.<br />
<br />
; Polarization parameters - ''PSI_POL'', ''EPSILON'' :These are the direction of maximum polarization, defined with the beam in the fiducial orientation described above, that is, before rotation onto the detector position, and the cross-polarization contamination (or leakage). These values are determined from ground-based measurements.<br />
<br />
; Beam parameters - ''FWHM'', ''ELLIPTICITY'', ''POSANG'' : These are the mean FWHM of the scanning beam (in arcmin, the beam ellipticity (no units), and the position angle of the beam major axis. The scanning beam is that recovered from the observation of bright planets; details in [[Beams]] section.<br />
<br />
; Noise parameters - ''NET_TOT'', ''NET_WHT'', ''F_KNEE'', ''ALPHA'' : Two NETs are given: one determined from the total noise (rms of the noise timeline) and one determined from the white noise level of the noise spectrum. The ''F_KNEE'' and ''ALPHA'' parameters are the frequency where the ''1/f'' noise component meets the white noise level, and the slope of the former. The NETs are in units of Kcmb or MJy/sr * sqrt(s). These values are determined from the signal timelines as described in [[TOI processing|TOI processing]] chapter.<br />
<br />
In the HFI RIMO, this table includes entries for the RTS bolometers (143-8 and 545-3), which are approximate or 0.00 when not evaluated.<br />
<br />
--><br />
<br />
'' Map-level parameter data ''<br />
<br />
The map-level data table contains the effective beam solid angle (total and out to different multiples of the beamFWHM) and noise information. It is written into a BINTABLE extension named ''MAP_PARAMS'' whose structure is different for HFI and LFI and is as follows. The noise description below is very simplified; a more accurate rendition can be obtained from the half-ring maps. Regarding the characterization of systematics, the user should use the survey differences.<br />
<br />
''' HFI '''<br />
<br />
; ''FREQUENCY'' (String) : a 3-digit string giving the reference frequency in GHz, i.e., of the form ''217''<br />
; ''OMEGA_F'', ''OMEGA_F_ERR'' (Real*4) : the full beam solid angle and its uncertainty, in armin<sup>2</sup><br />
; ''OMEGA_1'', ''OMEGA_1_DISP'' (Real*4) : the beam solid angle out to 1FWHM, and its dispersion, in arcmin<sup>2</sup><br />
; ''OMEGA_2'', ''OMEGA_2_DISP'' (Real*4) : the beam solid angle out to 2FWHM, and its dispersion, in arcmin<sup>2</sup><br />
; ''FWHM'' (Real*4) : FWHM of a Gaussian beam having the same (total) solid angle, in armin<sup>2</sup>. This is the best value for source flux determination<br />
; ''FWHMGAUS'' (Real*4) : FWHM derived from best Gaussian fit to beam maps, in armin<sup>2</sup>. This is the best value for source identification<br />
; ''NOISE'' (Real*4) : This is the typical noise/valid observation sample as derived from the high-''l'' spectra of the half-ring maps, in the units of the corresponding map<br />
<br />
For the Omega columns, the 'DISP' (for ''dispersion'') column gives an estimate of the spatial variation as a function of position on the sky. This is the variation induced by combining the scanning beam determined from the planet observations with the scanning strategy, as described in [[Beams]].<br />
<br />
''' LFI '''<br />
<br />
; ''FREQUENCY'' (String) : a 3-digit string giving the reference frequency in GHz, i.e., of the form ''030, 044, 070''<br />
; ''FWHM'' (Real*8) : FWHM of a Gaussian beam having the same (total) solid angle, in arcmin<br />
; ''NOISE'' (Real*8) : This is the average noise in T<math>\cdot</math>s<sup>1/2</sup> <br />
; ''CENTRALFREQ'' (Real*4) : This is the average central frequency in GHz<br />
; ''FWHM_EFF'', ''FWHM_EFF_SIGMA'' (Real*4) : This is the average FWHM of the effective beam, in arcmin, and its dispersion<br />
; ''ELLIPTICITY_EFF'', ''ELLIPTICITY_EFF_SIGMA'' (Real*4) : This is the average ellipticity and its dispersion<br />
; ''SOLID_ANGLE_EFF'', ''SOLID_ANGLE_EFF_SIGMA'' (Real*4) : This is the average full beam solid angle, in arcmin<sup>2</sup>, and its dispersion<br />
<br />
'' Effective band transmission profiles ''<br />
<br />
The effective filter bandpasses are given in different BINTABLE extensions. The extension is named ''BANDPASS_{name}'', where ''name'' specified the frequency channel. In the case of the maps, the bandpasses are a weighted average of the bandpasses of the detectors that are used to build the map. For details see {{PlanckPapers|planck2013-p03d}}. The bandpasses are given as 4-column tables containing:<br />
<br />
''' HFI '''<br />
<br />
; ''WAVENUMBER'' (Real*4) : the wavenumber in cm-1, conversion to GHz is accomplished by multiplying by <math>10^{-7}c</math> [mks].<br />
; ''TRANSMISSION'' (Real*4) : the transmission (normalized to 1 at the max for HFI)<br />
; ''ERROR'' (Real*4) : the statistical <math>1\sigma</math> uncertainty for the transmission profile.<br />
; ''FLAG'' (Integer) : a flag indicating if the data point is an independent frequency data point (nominally the case), or an FTS instrument line shape (ILS)-interpolated data point. The frequency data has been over-sampled by a factor of ~10 to assist in CO component separation efforts {{PlanckPapers|planck2013-p03a}}{{PlanckPapers|planck2013-p03d}}.<br />
<br />
The number of rows will differ among the different extensions, but are the same, by construction, within each extension. Tables with the unit conversion coefficients and color correction factors for the HFI detectors (and LFI in some instances), including uncertainty estimates based on the uncertainty of the HFI detector spectral response are given in [[UC_CC_Tables | this appendix]].<br />
<br />
''' LFI '''<br />
<br />
; ''WAVENUMBER'' (Real*8) : the wavenumber in GHz.<br />
; ''TRANSMISSION'' (Real*8) : the transmission (normalized to have an integral of 1 for LFI)<br />
; ''UNCERTAINITY'' (Real*4) : the statistical <math>1\sigma</math> uncertainty for the transmission profile (not provided for LFI)<br />
; ''FLAG'' (Character) : a flag, not used by now by the LFI<br />
<br />
The number of rows will differ among the different extensions, but are the same, by construction, within each extension. <br />
<br />
<!--<br />
'' Detector noise spectra ''<br />
<br />
There are no detector-level noise data in the RIMO for this release<br />
<br />
; HFI: these are the ring noise spectra averaged for rings NN to MM in order to give a representative spectrum. The spectra of all 50 valid bolometers are given in a single table.<br />
; LFI : TBW<br />
<br />
The keyword ''F_NYQ'' gives the Nyquist frequency, and can be used together with the number of points in the spectrum to reconstruct the frequency scale. The BINTABLE has the following structure:<br />
--><br />
<br />
'' Beam Window Functions ''<br />
<br />
Beam window functions and associated error descriptions are written into a BINTABLE for each ''detection unit'', where ''detection unit'' consists of an auto or a cross product (for HFI only) of one (or two) frequency maps or detset maps used in the likelihood. Here they are: <br />
<br />
; ''For the HFI'':<br />
* the 6 HFI frequency channels, producing 21 extensions<br />
** 100, 143, 217, 353, 545, 857<br />
* 26 detsets, producing 351 extensions; the detsets used are, by frequency channel:<br />
** 100-DS1, 100-DS2,<br />
** 143-DS1, 143-DS2, 143-5, 143-6, 143-7,<br />
** 217-DS1, 217-DS2, 217-1, 217-2, 217-3, 217-4, <br />
** 353-DS1, 353-DS2, 353-1, 353-2, 353-7, 353-8,<br />
** 545-1, 545-2, 545-4,<br />
** 857-1, 857-2, 857-3, 857-4<br />
<br />
; ''For the LFI'':<br />
* the 3 LFI frequency channels, producing 3 extensions<br />
** 30, 44, 70<br />
<br />
<br />
and the extension names are of the form ''BEAMWF_U1XU2'' where U1 and U2 are one (possibly the same) detection unit from one of the main groups above (i.e. there are no cross products between detsets and frequency channels, or between HFI and LFI). Each extension contains the columns:<br />
; ''NOMINAL'' (Real*4) : the beam window function proper,<br />
; ''EIGEN_n'' (Real*4, n=1-5 for the HFI, n=1-4 for the LFI): the five/four corresponding error modes.<br />
<br />
and the following keywords give further information, only for the HFI:<br />
; ''NMODES'' (Integer) : the number of EIGEN_* modes,<br />
; ''LMIN'' and ''LMAX'' (Integer) : the starting and ending (both included) multipoles of the vectors NOMINAL and EIGEN_*<br />
; ''LMIN_EM'' and ''LMAX_EM'' (Integer) : that give the range of the valid samples of the EIGEN_* vectors. Here ''LMAX_EM'' is always less than or equal to ''LMAX''. On the range ''LMAX_EM''+1 to ''LMAX'' the values of EIGEN_* are set to NaN, while the values of NOMINAL only are a Gaussian extrapolation of the lower multipole window function, only provided for convenience.<br />
; ''CORRMAT'' (string) : the name of the extension containing the corresponding beam correlation matrix<br />
<br />
'' Beam Correlation Matrix ''<br />
<br />
Two beam correlation matrices are given for the HFI, in two ''IMAGE'' extensions:<br />
; ''CORRBEAM_FREQ'' (Real*8) : for the frequency channels (21 units), 105x015 pixel matrix,<br />
; ''CORRBEAM_DSET'' (Real*8) : for the detsets (351 units), 1755x1755 pixel matrix <br />
Each is a symmetric matrix with 1-valued diagonal, made of NBEAMS*NBEAMS blocks, each block being NMODES*NMODES in size. The n$^{th}$ row- (and column-) block entry relates to the B(l) model whose name is indicated in ROWn = BEAMWF_U1XU2 keywords, and the corresponding eigenmodes are stored in a HDU of the same name. <br />
<br />
Each extension contains also the following keywords:<br />
; ''NDETS'' (Integer) : the number of detector units<br />
; ''NBEAMS'' (Integer) : the number of beams = NSETS * (NSETS+1) / 2<br />
; ''NMODES'' (Integer) : here 5<br />
; ''L_PLUS'' (Integer) : Eigenmode > 0 to break degeneracies<br />
; ''BLOCKn'' (string) : for n=1-NBEAMS, gives the name of the extension containing the beam WF and error eigenmodes for the nth block<br />
and some other ones for internal data checking and traceability<br />
<br />
No beam correlation matrices are produced by the LFI by now.<br />
<br />
''Appendices''<br />
<br />
* [[UC_CC_Tables | Unit correction and color correction tables]]<br />
<br />
<br />
<br />
</div><br />
</div><br />
<br />
== References ==<br />
<br />
<References /><br />
<br />
<br />
[[Category:Mission products|003]]</div>Azaccheihttps://wiki.cosmos.esa.int/planck-legacy-archive/index.php?title=Correction_maps&diff=14118Correction maps2018-07-06T14:17:51Z<p>Azacchei: /* LFI BandPass Leackage correction */</p>
<hr />
<div>==General description==<br />
<br />
Different corrections have been applied to the 2018 data releases, and when available, correction maps are provided in PLA.<br />
<br />
Below short description these corrections can be found, furthers details for LFI are avialble in {{PlanckPapers|planck2016-l02}}.<br />
<br />
===LFI Template===<br />
<br />
In the 2018 release an iterative schema for the phometric calibration has been adopted. In case of 70GHz this iterative procedure didn't converge at the time of the release. As a consequence, we expect that low-level residuals are still present<br />
in the 2018 LFI maps, with a pattern similar to that of the 2015 maps, though with significantly lower amplitude. For the 2018 release, we adopt the dfference between the two last iterations as a spatial template of residual gain uncertainties projected onto the sky. This template is used only at 70 GHz (already applyed in the maps released) and made available trought the PLA (see section 3 of {{PlanckPapers|planck2016-l02}}).<br />
<br />
===LFI BandPass Leackage correction===<br />
<br />
BandPass Leackage correction estimation is described is section 7 of {{PlanckPapers|planck2016-l02}}. We release BandPass corrected maps, BandPass uncorrected maps and BandPass correction Maps.<br />
<br />
===List of LFI Correction maps===<br />
<br />
{| class="wikitable" align="center" style="text-align"left" border="1" cellpadding="15" cellspacing="20" width=1000px<br />
|+ '''LFI FITS Correction Maps'''<br />
|- bgcolor="ffdead"<br />
! Type || Filename || Comment<br />
|-<br />
| 70GHz Template ||LFI_CorrMap_070-Gain-tpl_1024_R3.00_full.fits ||ONLY for the 70GHz <br />
|-<br />
| BandPass Correction full period ||LFI_CorrMap_???-BPassCorr_1024_R3.00_full.fits || n/a<br />
|-<br />
| BandPass Correction full period Ring-Half || LFI_CorrMap_???-BPassCorr_1024_R3.00_full-ringhalf-?.fits || n/a <br />
|-<br />
| BandPass Correction single year || LFI_CorrMap_???-BPassCorr_1024_R3.00_year-?.fits || n/a<br />
|-<br />
| BandPass Correction year combination || LFI_CorrMap_???-BPassCorr_1024_R3.00_year?-?.fits || n/a<br />
|-<br />
| BandPass Correction survey combination || LFI_CorrMap_???-BPassCorr_1024_R3.00_survey-1-3-5-6-7-8.fits || n/a<br />
|-<br />
|}</div>Azaccheihttps://wiki.cosmos.esa.int/planck-legacy-archive/index.php?title=Correction_maps&diff=14117Correction maps2018-07-06T14:17:25Z<p>Azacchei: </p>
<hr />
<div>==General description==<br />
<br />
Different corrections have been applied to the 2018 data releases, and when available, correction maps are provided in PLA.<br />
<br />
Below short description these corrections can be found, furthers details for LFI are avialble in {{PlanckPapers|planck2016-l02}}.<br />
<br />
===LFI Template===<br />
<br />
In the 2018 release an iterative schema for the phometric calibration has been adopted. In case of 70GHz this iterative procedure didn't converge at the time of the release. As a consequence, we expect that low-level residuals are still present<br />
in the 2018 LFI maps, with a pattern similar to that of the 2015 maps, though with significantly lower amplitude. For the 2018 release, we adopt the dfference between the two last iterations as a spatial template of residual gain uncertainties projected onto the sky. This template is used only at 70 GHz (already applyed in the maps released) and made available trought the PLA (see section 3 of {{PlanckPapers|planck2016-l02}}).<br />
<br />
===LFI BandPass Leackage correction===<br />
<br />
BandPass Leackage correction estimation is described is section 7 of {{PlanckPapers|planck2016-l02}}. We release BandPass corrected maps, BandPass uncorrected maps and BandPass correction Maps LFI_CorrMap_???-BPassCorr_1024_R3.00_???.fits<br />
<br />
===List of LFI Correction maps===<br />
<br />
{| class="wikitable" align="center" style="text-align"left" border="1" cellpadding="15" cellspacing="20" width=1000px<br />
|+ '''LFI FITS Correction Maps'''<br />
|- bgcolor="ffdead"<br />
! Type || Filename || Comment<br />
|-<br />
| 70GHz Template ||LFI_CorrMap_070-Gain-tpl_1024_R3.00_full.fits ||ONLY for the 70GHz <br />
|-<br />
| BandPass Correction full period ||LFI_CorrMap_???-BPassCorr_1024_R3.00_full.fits || n/a<br />
|-<br />
| BandPass Correction full period Ring-Half || LFI_CorrMap_???-BPassCorr_1024_R3.00_full-ringhalf-?.fits || n/a <br />
|-<br />
| BandPass Correction single year || LFI_CorrMap_???-BPassCorr_1024_R3.00_year-?.fits || n/a<br />
|-<br />
| BandPass Correction year combination || LFI_CorrMap_???-BPassCorr_1024_R3.00_year?-?.fits || n/a<br />
|-<br />
| BandPass Correction survey combination || LFI_CorrMap_???-BPassCorr_1024_R3.00_survey-1-3-5-6-7-8.fits || n/a<br />
|-<br />
|}</div>Azaccheihttps://wiki.cosmos.esa.int/planck-legacy-archive/index.php?title=Correction_maps&diff=14116Correction maps2018-07-06T14:16:29Z<p>Azacchei: </p>
<hr />
<div>==General description==<br />
<br />
Different corrections have been applied to the 2018 data releases, and when available, correction maps are provided in PLA.<br />
<br />
Below short description these corrections can be found, furthers details for LFI are avialble in {{PlanckPapers|planck2016-l02}}.<br />
<br />
==LFI Template==<br />
<br />
In the 2018 release an iterative schema for the phometric calibration has been adopted. In case of 70GHz this iterative procedure didn't converge at the time of the release. As a consequence, we expect that low-level residuals are still present<br />
in the 2018 LFI maps, with a pattern similar to that of the 2015 maps, though with significantly lower amplitude. For the 2018 release, we adopt the dfference between the two last iterations as a spatial template of residual gain uncertainties projected onto the sky. This template is used only at 70 GHz (already applyed in the maps released) and made available trought the PLA (see section 3 of {{PlanckPapers|planck2016-l02}}).<br />
<br />
==LFI BandPass Leackage correction==<br />
<br />
BandPass Leackage correction estimation is described is section 7 of {{PlanckPapers|planck2016-l02}}. We release BandPass corrected maps, BandPass uncorrected maps and BandPass correction Maps LFI_CorrMap_???-BPassCorr_1024_R3.00_???.fits<br />
<br />
{| class="wikitable" align="center" style="text-align"left" border="1" cellpadding="15" cellspacing="20" width=1600px<br />
|+ '''LFI FITS Correction Maps'''<br />
|- bgcolor="ffdead"<br />
! Type || Filename || Comment<br />
|-<br />
| 70GHz Template ||LFI_CorrMap_070-Gain-tpl_1024_R3.00_full.fits ||ONLY for the 70GHz <br />
|-<br />
| BandPass Correction full period ||LFI_CorrMap_???-BPassCorr_1024_R3.00_full.fits || n/a<br />
|-<br />
| BandPass Correction full period Ring-Half || LFI_CorrMap_???-BPassCorr_1024_R3.00_full-ringhalf-?.fits || n/a <br />
|-<br />
| BandPass Correction single year || LFI_CorrMap_???-BPassCorr_1024_R3.00_year-?.fits || n/a<br />
|-<br />
| BandPass Correction year combination || LFI_CorrMap_???-BPassCorr_1024_R3.00_year?-?.fits || n/a<br />
|-<br />
| BandPass Correction survey combination || LFI_CorrMap_???-BPassCorr_1024_R3.00_survey-1-3-5-6-7-8.fits || n/a<br />
|-<br />
|}</div>Azaccheihttps://wiki.cosmos.esa.int/planck-legacy-archive/index.php?title=Correction_maps&diff=14115Correction maps2018-07-06T14:03:32Z<p>Azacchei: </p>
<hr />
<div>==General description==<br />
<br />
Different corrections have been applied to the 2018 data releases, and when available, correction maps are provided in PLA.<br />
<br />
Below short description these corrections can be found, furthers details for LFI are avialble in {{PlanckPapers|planck2016-l02}}.<br />
<br />
==LFI Template==<br />
<br />
In the 2018 release an iterative schema for the phometric calibration has been adopted. In case of 70GHz this iterative procedure didn't converge at the time of the release. As a consequence, we expect that low-level residuals are still present<br />
in the 2018 LFI maps, with a pattern similar to that of the 2015 maps, though with significantly lower amplitude. For the 2018 release, we adopt the dfference between the two last iterations as a spatial template of residual gain uncertainties projected onto the sky. This template is used only at 70 GHz (already applyed in the maps released) and made available trought the PLA LFI_CorrMap_070-Gain-tpl_1024_R3.00_full.fits. I shoudl simply Subtracted from teh map<br />
<br />
==LFI BandPass Leackage correction==<br />
<br />
BandPass Leackage correction estimation is described is section 7 of {{PlanckPapers|planck2016-l02}}. We release BandPass corrected maps, BandPass uncorrected maps and BandPass correction Maps LFI_CorrMap_???-BPassCorr_1024_R3.00_???.fits</div>Azaccheihttps://wiki.cosmos.esa.int/planck-legacy-archive/index.php?title=Frequency_maps&diff=14114Frequency maps2018-07-06T13:48:15Z<p>Azacchei: /* File names */</p>
<hr />
<div>{{DISPLAYTITLE:Frequency maps in Temperature and Polarization}}<br />
==General description==<br />
<br />
Sky maps give the best estimate of the intensity and polarization (Stokes <i>Q</i> and <i>U</i> components), if available, of the signal from the sky after removal, as far as possible, of known systematic effects (mostly instrumental, but including also the solar and Earth-motion dipoles, Galactic stray light, and the zodiacal light). The Planck Collaboration has made three releases of maps, in 2013, 2015 and 2018. This section describes the 2018 release. For descriptions of the other two releases, please go to 2013, and 2015.<br />
<br />
In the 2013, 2015 and 2018 releases, sky maps are provided for the full Planck mission using all valid detectors in each frequency channel, and also for various subsets obtained by splitting the mission into various time ranges or into subsets of the detectors in a given channel, or by considering only odd or even pointing periods. These products are especially interesting for characterization purposes (see also the [[HFI-Validation | data validation]] section), though some are also useful for the study of source variability. The details of the start and end of the time ranges are given in the table below. <br />
<br />
For this (2018) release, HFI is providing a more limited subset of maps that include the full channel maps, the half-mission and the odd-even ring splits. Also, note that for the 353 GHz band, both full channel and PSBs only maps are provided, and that by default it is the PBS-only maps that are served.<br />
<br />
<br />
{| border="1" cellpadding="3" cellspacing="0" align="center" style="text-align:left" width=800px<br />
|+ '''Ranges for mission and surveys'''<br />
|- bgcolor="ffdead" <br />
! Range || ODs || HFI rings || pointing-IDs || Comment<br />
|-<br />
|Nominal mission || 91 - 563 || 240 - 14723 || 00004200 - 03180200 ||<br />
|-<br />
|Full mission || 91 - 974 || 240 - 27005 || 00004200 - 05322620 || For HFI<br />
|-<br />
|Full mission || 91 - 1543 || n/a || 00004200 - 06511160 || For LFI<br />
|-<br />
|Survey 1 || 91 - 270 || 240 - 5720 || 00004200 - 01059820 ||<br />
|-<br />
|Survey 2 || 270 - 456 || 5721 - 11194 || 01059830 - 02114520 ||<br />
|-<br />
|Survey 3 || 456 - 636 || 11195 - 16691 || 02114530 - 03193660 ||<br />
|-<br />
|Survey 4 || 636 - 807 || 16692 - 21720 || 03193670 - 04243900 ||<br />
|-<br />
|Survey 5 || 807 - 974 || 21721 - 26050 || 05267180 - 05322590 || End of mission for HFI<br />
|-<br />
|Survey 5 || 807 - 993 || n/a || 05267180 - 06344800 || End of survey for LFI<br />
|-<br />
|Survey 6 || 993 - 1177 || n/a || 06344810 - 06398120 || LFI only <br />
|-<br />
|Survey 7 || 1177 - 1358 || n/a || 06398130 - 06456410 || LFI only <br />
|-<br />
|Survey 8 || 1358 - 1543 || n/a || 06456420 - 06511160 || LFI only <br />
|-<br />
|HFI mission-half-1 || 91 - 531 || 240 - 13471 || 00004200 - 03155580 ||<br />
|-<br />
|HFI mission-half-2 || 531 - 974 || 13472 - 27005 || 03155590 - 05322590 ||<br />
|-<br />
|LFI Year 1 || 91 - 456 || n/a || 00004200 - 02114520 ||<br />
|-<br />
|LFI Year 2 || 456 - 807 || n/a || 02114530 - 04243900 ||<br />
|-<br />
|LFI Year 3 || 807 - 1177 || n/a || 05267180 - 06398120 ||<br />
|-<br />
|LFI Year 4 || 1177 - 1543 || n/a || 06398130 - 06511160 ||<br />
|-<br />
|}<br />
<br />
To help in further processing, there are also masks of the Galactic plane and of point sources, each provided for several different depths. <br />
<br />
All sky maps are in HEALPix format, with <i>N</i><sub>side</sub>=1024 (for LFI 30, 44, and 70GHz) and 2048 (for LFI 70GHz and HFI), in Galactic coordinates, and with nested ordering. <br />
<br />
'''WARNING''': The HEALPix convention for polarization is <b>not</b> the same as the IAU convention ([[#Polarization convention used in the Planck project|Section 8 on this page]]).<br />
<br />
The signal is given in units of K<sub>CMB</sub> for 30 to 353 GHz, and of MJy.sr<sup>-1</sup> (for a constant &nu;<i>I</i><sub>&nu;</sub> energy distribution) for 545 and 857 GHz. For each frequency channel, the intensity and polarization maps are packaged into a "BINTABLE" extension of a FITS file together with a hit-counts map (or "hits map", for short, giving the number of observation samples that are accumulated in a pixel, all detectors combined) and with the variance and covariance maps. Additional information is given in the FITS file header. The structure of the FITS file is given in the [[#FITS_file_structure | FITS file structure]] section below.<br />
<br />
==Production process==<br />
<br />
Sky maps are produced by appropriately combining the data from all working detectors in a frequency channel over some period of the mission. They give the best estimate of the signal from the sky (unpolarized) after removal, as far as possible, of known systematic effects and of the dipole signals induced by the motion of the solar system in the CMB and of the Planck satellite in the solar system. In particular, they include the zodiacal light emission ("zodi" for short) and also the scattering from the far sidelobes of the beams (FSL). More on this below.<br />
<br />
=== HFI processing ===<br />
<br />
The mapmaking and calibration process is described in detail in the [[Map-making_LFI | mapmaking]] section and in the {{PlanckPapers|planck2016-XLVI}} paper, where detailed references can be found. In brief, the timelines are cleaned and calibrated and converted into HealPix rings (HPRs), then ''SRoll'' is applied to destripe them in polarised space (removal of very low frequency noise by minimising differences at ring crossing points), to remove knows systematic effects (including the flux calibration), and to project them onto a HealPix map.<br />
<br />
The processing yields maps of the signal, hit counts and auto- and cross-variance maps for the 6 full channel and for a pseudo-channel built from the 353 PSBs only. For each channel HFI provides <br />
* a map for the full mission<br />
* two maps for each half-mission<br />
* two maps for built from odd or even rings only<br />
<br />
for a total of 35 maps. <br />
<br />
==== PR3 HFI products ====<br />
<br />
===== Healpix Pixel Rings (HPRs) =====<br />
''SRoll'' main products are the HFI frequency maps. Nevertheless, we also make available the Healpix Pixel Rings (HPRs) of those maps, ie. the data before projection. See [[Healpix_Rings_HFI| description of those files]].<br />
<br />
===== Frequency maps =====<br />
<br />
The 35 HFI frequency maps of the PR3 Legacy Release are the followings:<br />
<br />
{| border="1" cellpadding="3" cellspacing="0" align="center" style="text-align:left" width=800px<br />
|+ '''PR3 HFI frequency maps'''<br />
|- bgcolor="ffdead"<br />
!<br />
!100 GHz<br />
!143 GHz<br />
!217 GHz<br />
!353 GHz<br />
!353_PSB GHz<br />
!545 GHz<br />
!857 GHz<br />
|-<br />
| Full mission<br />
| I, Q, U<br />
| I, Q, U<br />
| I, Q, U<br />
| I, Q, U<br />
| I, Q, U<br />
| I<br />
| I<br />
|-<br />
| Half mission 1<br />
| I, Q, U<br />
| I, Q, U<br />
| I, Q, U<br />
| I, Q, U<br />
| I, Q, U<br />
| I<br />
| I<br />
|-<br />
| Half mission 2<br />
| I, Q, U<br />
| I, Q, U<br />
| I, Q, U<br />
| I, Q, U<br />
| I, Q, U<br />
| I<br />
| I<br />
|-<br />
| Odd rings<br />
| I, Q, U<br />
| I, Q, U<br />
| I, Q, U<br />
| I, Q, U<br />
| I, Q, U<br />
| I<br />
| I<br />
|-<br />
| Even rings<br />
| I, Q, U<br />
| I, Q, U<br />
| I, Q, U<br />
| I, Q, U<br />
| I, Q, U<br />
| I<br />
| I<br />
|}<br />
<br />
See [[Frequency_maps|description of those files]]. These maps are available on the [[https://www.cosmos.esa.int/web/planck/pla| Planck Legacy Archive]].<br />
<br />
<br />
=== LFI processing ===<br />
LFI maps were constructed with the MADAM mapmaking code, version 3.7.4. The code is based on a generalized destriping technique, where the correlated noise component is modelled as a sequence of constant offsets, called "baselines". A noise filter was used to constrain the baseline solution, allowing the use of 0.25-s and 1-s baselines for the 30 and 44GHz, and 70 GHz channels, respectively. See section 6 of {{PlanckPapers|planck2016-l02}}.<br />
<br />
<br />
Radiometers were combined according to the horn-uniform weighting scheme to minimize systematics. The flagged samples were excluded from the analysis by setting their weights to <i>C</i><sub>w</sub><sup>-1</sup> = 0. The Galaxy region was masked out in the destriping phase, to reduce errors arising from strong signal gradients. The polarization component was included in the analysis. <br />
<br />
; Dipole and Far Side Lobe correction: Input timelines are cleaned by the 4&pi;-convolved dipole and Galactic stray light, obtained as a convolution of the 4&pi; in-band far sidelobes and Galactic simulations, as explained in {{PlanckPapers|planck2016-l02}}. <br />
<br />
Scaling of the maps due to beam effects is taken into account in the LFI's beam functions (as provided in [[The_RIMO|the RIMO]]) which should be used for analysis of diffuse components.<br />
<br />
; Bandpass leakage correction :LFI high-resolution maps have been reseleased corrected for bandpass leakage or uncorrected. Further details about the procedure used to generate the bandpass correction maps can be found in section 7 of {{PlanckPapers|planck2016-l02}}.<br />
<br />
; Map zero-level : The 30, 44 and 70 GHz, maps are corrected for a zero-level monopole by applying an offset correction (see the LFI Calibration paper, {{PlanckPapers|planck2014-a06}}). Note that the offset applied is indicated in the header as a comment keyword.<br />
<br />
A detailed description of the mapmaking procedure is given in {{PlanckPapers|planck2013-p02}}, {{PlanckPapers|planck2014-a03}}, {{PlanckPapers|planck2014-a07}} and in the [[Map-making LFI#Map-making|Mapmaking]] section here, in {{PlanckPapers|planck2016-l02}} only a summary is reported.<br />
<br />
==Types of map ==<br />
<br />
=== Full-mission, full-channel maps (7 HFI, 4 LFI)===<br />
<br />
Full channel maps are built using all the valid detectors of a frequency channel and cover either the full or the nominal mission. For HFI, the 143-8 and 545-3 bolometers are rejected entirely, since they are seriously affected by RTS noise. HFI provides the Q and U components for the 100, 143, 217 and 353 GHz channels only. LFI provides the <i>I</i>, <i>Q</i>, and <i>U</i> maps for all the channels. Note that the HFI and LFI <i>Q</i> and <i>U</i> maps are corrected for bandpass leakage, version without correction for LFi is also provided. The <i>I</i>, <i>Q</i>, and <i>U</i> maps are displayed in the figures below. The colour range here is set using a histogram equalization scheme (from HEALPix) that is useful for these non-Gaussian data fields. For visualization purposes, the <i>Q</i> and <i>U</i> maps shown here have been smoothed with a 1&deg; Gaussian kernel, otherwise they look like noise to the naked eye. The 70 GHz full map is also available at <i>N</i><sub>side</sub>=2048.<br />
<br />
The high dynamic range colour scheme of the Planck maps is described [https://wiki.cosmos.esa.int/planck-legacy-archive/index.php/Planck_high_dynamic_range_colour_palette here].<br />
<br />
<center><br />
<gallery style="padding:0 0 0 0;" perrow=3 widths=260px heights=160px> <br />
File: LFI_030GHz_dx12_I.png| '''Full mission <i>I</i>, 30 GHz.'''<br />
File: LFI_044GHz_dx12_I.png| '''Full mission <i>I</i>, 44 GHz.'''<br />
File: LFI_070GHz_dx12_I.png| '''Full mission <i>I</i>, 70 GHz.'''<br />
File: SkyMap100e.png| '''Full mission <i>I</i>, 100 GHz.'''<br />
File: SkyMap143e.png| '''Full mission <i>I</i>, 143 GHz.'''<br />
File: SkyMap217e.png| '''Full mission <i>I</i>, 217 GHz.'''<br />
File: SkyMap353e.png| '''Full mission <i>I</i>, 353 GHz.'''<br />
File: SkyMap545e.png| '''Full mission <i>I</i>, 545 GHz.'''<br />
File: SkyMap857e.png| '''Full mission <i>I</i>, 857 GHz.'''<br />
</gallery><br />
</center><br />
<br><br />
<center><br />
<gallery style="padding:0 0 0 0;" perrow=3 widths=260px heights=160px> <br />
File: LFI_030GHz_dx12_Q.png| '''Full mission <i>Q</i>, 30 GHz.'''<br />
File: LFI_044GHz_dx12_Q.png | '''Full mission <i>Q</i>, 44 GHz.'''<br />
File: LFI_070GHz_dx12_Q.png | '''Full mission <i>Q</i>, 70 GHz.'''<br />
File: HFI_Skymap_100_full_bplcorrected_sm1deg_Qb.png | '''Full mission <i>Q</i>, 100 GHz.'''<br />
File: HFI_Skymap_143_full_bplcorrected_sm1deg_Qb.png | '''Full mission <i>Q</i>, 143 GHz.'''<br />
File: HFI_Skymap_217_full_bplcorrected_sm1deg_Qb.png | '''Full mission <i>Q</i>, 217 GHz.'''<br />
File: HFI_Skymap_353_full_bplcorrected_sm1deg_Qb.png | '''Full mission <i>Q</i>, 353 GHz.'''<br />
</gallery><br />
</center><br />
<br><br />
<center><br />
<gallery style="padding:0 0 0 0;" perrow=3 widths=260px heights=160px> <br />
File: LFI_030GHz_dx12_U.png| '''Full mission <i>U</i>, 30 GHz.'''<br />
File: LFI_044GHz_dx12_U.png | '''Full mission <i>U</i>, 44 GHz.'''<br />
File: LFI_070GHz_dx12_U.png | '''Full mission <i>U</i>, 70 GHz.'''<br />
File: HFI_Skymap_100_full_bplcorrected_sm1deg_Ub.png | '''Full mission <i>U</i>, 100 GHz.'''<br />
File: HFI_Skymap_143_full_bplcorrected_sm1deg_Ub.png | '''Full mission <i>U</i>, 143 GHz.'''<br />
File: HFI_Skymap_217_full_bplcorrected_sm1deg_Ub.png | '''Full mission <i>U</i>, 217 GHz.'''<br />
File: HFI_Skymap_353_full_bplcorrected_sm1deg_Ub.png | '''Full mission <i>U</i>, 353 GHz.'''<br />
</gallery><br />
<br />
</center><br />
<br />
=== Full mission light maps, full channel maps (7 HFI, 7 LFI)===<br />
<br />
These maps are based on the Full mission maps but contain fewer columns, IQU from 30 to 353 GHz, and I only at 545 and 857 GHz. These maps have been produced to reduce the transfer time of the most downloaded frequency full mission maps.<br />
<br />
=== Single-survey, full-channel maps (35 LFI)===<br />
<br />
Single-survey maps are built using all valid detectors of a frequency channel; they separately cover the different sky surveys. The surveys are defined as the times over which the satellite spin axis rotates by 180&deg;, which, due to the position of the detectors in the focal plane does not cover the full sky, but a fraction between about 80% and 90%, depending on detector position. During adjacent surveys the sky is scanned in opposite directions (more precisely it is the ecliptic equator that is scanned in opposite directions). While these are useful to investigate variable sources, they are also used to study the systematics of the time-response of the detectors as they scan bright sources, like the Galactic Plane, in different directions during different survey. Note that the HFI and LFI missions cover five and eight surveys, respectively, and in the case of HFI the last survey in incomplete.<br />
The 70 GHz survey maps are available also at <i>N</i><sub>side</sub>=2048. Note that LFI provides a special survey-map combination used in the low-&#8467; analysis; this maps, available at the three LFI frequencies, 30, 44, and 70 GHz, was built using the combination of Surveys 1, 3, 5, 6, 7, and 8.<br />
<br />
=== Year maps, full-channel maps (16 LFI)===<br />
<br />
These maps are built using the data of Surveys 1+2, Surveys 3+4, and so forth. They are used to study long-term systematic effects. The 70 GHz years maps are available also at <i>N</i><sub>side</sub>=2048.<br />
<br />
===Half-mission maps, full-channel maps (14 HFI, 12 LFI)===<br />
<br />
For HFI, the half mission is defined after eliminating those rings that are discarded for all bolometers, many of which occurred during the 5th survey when the "End-of-Life" tests were performed. The remaining rings are divided in half to define the two halves of the mission. This exercise is done for the full mission only.<br />
<br />
For LFI, instead of the half-mission maps, the following year combinations have been created: Year 1+2, Year 1+3, Year 2+4, Year 3+4,<br />
<br />
===Full mission, single-detector maps (22 LFI)===<br />
<br />
For LFI, all the 22 Radiometers maps are available, and (obviously) only in Stokes <i>I</i>.<br />
<br />
===Full-mission, detector-set or detector-pairs maps (8 LFI)===<br />
<br />
The objective here is to build independent temperature (<i>I</i>) and polarization (<i>Q</i> and <i>U</i>) maps using the two pairs of polarization-sensitive detectors of each channel where they are available, i.e., for the 44-353 GHz channels. The table below indicates which detectors were used to build each detector set (detset).<br />
<br />
{| border="1" cellpadding="3" cellspacing="0" align="center" style="text-align:left" width=600px<br />
|+ '''Definition of LFI detector pairs'''<br />
|- bgcolor="ffdead" <br />
!Frequency || Horn pair || Comment <br />
|-<br />
|44 GHz || 24 || This map is only in temperature<br />
|-<br />
|44 GHz || 25 and 26 || <br />
|-<br />
|70 GHz || 18 and 23 || Available also at <i>N</i><sub>side</sub>=2048<br />
|-<br />
|70 GHz || 19 and 22 || Available also at <i>N</i><sub>side</sub>=2048<br />
|-<br />
|70 GHz || 20 and 21 || Available also at <i>N</i><sub>side</sub>=2048<br />
|}<br />
<br />
===Half-ring maps (62 LFI)===<br />
<br />
These maps are similar to the ones described above, but are built using only the first or the second halves of each ring (or pointing period). The HFI provides half-ring maps for the full mission only, as well as for the full channel, the detsets, and the single bolometers. The LFI provides half-ring maps for the full mission in each channel (70 GHz also at <i>N</i><sub>side</sub>=2048), for the full-mission radiometers, and for the full-mission horn pairs.<br />
<br />
=== Odd and even rings maps (14 HFI)<br />
<br />
As the name indicates, these are generated by using only the odd or only the even rings.<br />
<br />
=== Caveats and known issues ===<br />
<br />
'''TBC'''<br />
<br />
==== Caveats when using the HFI frequency maps ====<br />
Some imperfections have shown up in the tests of the HFI PR3 maps that were previously hidden by higher-level systematics in the previous PR2 data. These lead to guidelines for the proper use of the HFI PR3 data.<br />
<br />
===== Monopoles =====<br />
Monopoles, which cannot be extracted from Planck data alone, are adjusted at each frequency (as was done in the previous PR2 release). For component separation, this provides maps that can be used directly in combination with other tracers.<br />
This monopole includes a CIB model, a diffuse ISM signal adjusted on the HI tracer, and a zodiacal emission signal adjusted to the proper absolute intensity.<br />
<br />
=====Use of the 353 GHz SWBs ===== <br />
We deliver two data sets: the recommended one not using the 353 GHz SWBs data, and the other one including the 353 GHz SWBs for specific use like, for example, increasing the signal to noise level at high multipoles.<br />
<br />
===== Color correction and component separation=====<br />
Different responses between bolometers to different foregrounds cannot be used with the PR3 release to extract component maps. Single bolometer maps computed by Sroll in a frequency band, are all adjusted by construction to the band average response.<br />
<br />
===== Sub-pixel effect in very bright regions===== <br />
The bandpass corrections have been optimized for high latitude regions which implied to reduce the noise of the CO and dust bandpass templates to avoid the introduction of significant correlated noise. The effect is negligible for dust but not for CO in very bright regions. See [[subpixel_HFI|detailled description]].<br />
<br />
===== Solar dipole residual===== <br />
The ''Planck'' 2015 Solar dipole is removed from the PR3 HFI maps to be consistent with LFI maps and to facilitate comparison with the previous PR2 ones. The best Solar dipole determination from HFI PR3 data shows a small shift in direction of about 1', but a 1.8 &mu;K lower amplitude. Removal of the ''Planck'' 2015 Solar dipole thus leaves a small but non-negligible dipole residual in the HFI PR3 maps. To correct for this, and adjust maps at the best photometric calibration, users of the HFI PR3 maps should:<br />
# put back into the maps the ''Planck'' 2015 Solar dipole (d,l,b)= (3364.5 &plusmn; 2.0 &mu;K, 264.00 &plusmn; 0.03&deg;, 48.24 &plusmn; 0.02&deg;),<br />
# include the [[#Calibration accuracy|absolute calibration frequency bias]], i.e., multiply by 1 minus the calibration bias,<br />
# lastly, remove the [[#HFI 2018 Solar dipole|HFI 2018 Solar dipole]].<br />
<br />
==Inputs==<br />
=== HFI inputs ===<br />
<br />
The HFI mapmaking takes as input:<br />
* the cleaned TOIs of the signal from each detector, together with their flags, produced by the [[TOI processing|TOI processing]] pipeline;<br />
* the TOIs of pointing (quaternions), described in [[Detector_pointing|Detector pointing]];<br />
* bolometer-level characterization data, from the DPC's internal IMO (not distributed);<br />
* Planck orbit data, used to compute and remove the Earth's dipole;<br />
* Planck solar dipole information, used to calibrate the CMB channels;<br />
* planet models used to calibrate the Galactic channels.<br />
<br />
=== LFI inputs ===<br />
<br />
The MADAM mapmaker takes as input:<br />
* the calibrated timelines (for details see [[TOI processing LFI|TOI Processing]]);<br />
* the detector pointings (for details see [[Detector_pointing|Detector pointing]]);<br />
* the noise information in the form of 3-parameter (white noise level &sigma;, slope, and knee frequency <i>f</i><sub>knee</sub>) noise model (for details see [[The RIMO|RIMO]]).<br />
<br />
==Related products==<br />
=== Masks ===<br />
This section presents the "general purpose" masks. Other masks specific to certain products are packaged with those products.<br />
<br />
Note that for this release, HFI has not produced any new masks. <br />
<br />
==== Gatactic Centre masks ====<br />
<br />
'''TBW'''<br />
<br />
<br />
====Point source masks [TO BE REMOVED ??]====<br />
<br />
For HFI and LFI two sets of point-source masks are provided. <br />
* Intensity masks, which remove sources detected with S/N > 5. <br />
* Polarisation masks, which remove sources that have polarization detection significance levels of 99.97 % or greater at the position of a source detected in intensity. They were derived from the polarization maps with dust foreground bandpass mismatch leakage corrections applied. The area excised around each source has a radius of 3σ (width) of the beam, i.e., 1.27 FWHM (for LFI the cut around each source has a radius of 32 arcmin at 30GHz, 27 arcmin at 44 GHz, and 13 arcmin at 70 GHz).<br />
<br />
Both sets of masks are found in the files ''HFI_Mask_PointSrc_2048_R2.00.fits'' and ''LFI_Mask_PointSrc_2048_R2.00.fits'', in which the first extension contains the intensity masks, and the second contains the polarization masks.<br />
<br />
====Galactic plane masks [TO BE REMOVED ??]====<br />
<br />
Eight Galactic emission masks are provided, giving 20, 40, 60, 70, 80, 90, 97, and 99% sky coverage, derived from the 353 GHz map after CMB subtraction. These are independent of frequency channel. Three versions are given: not apodized; and apodized by 2&deg; and 5&deg;. The filenames are ''HFI_Mask_GalPlane-apoN_2048_R2.00.fits'', where <i>N</i> = 0, 2, and 5.<br />
<br />
The masks are shown below. The eight "GalPlane" masks are combined (added together) and shown in a single figure for each of the three apodizations. While the result is quite clear for the case of no apodization, it is less so for the apodized case. The "PointSrc" masks are shown separately for the intensity case.<br />
<br />
<center><br />
<gallery perrow=3 widths=260px heights=160px ><br />
File: GalPlaneMask_apo0.png | '''Galactic plane masks, no apodization.'''<br />
File: GalPlaneMask_apo2.png | '''Galactic plane masks, apodized to 2&deg;.'''<br />
File: GalPlaneMask_apo5.png | '''Galactic plane masks, apodized to 5&deg;.'''<br />
File: PointSrcMask_100.png | '''Point source mask, 100 GHz.'''<br />
File: PointSrcMask_143.png | '''Point source mask, 143 GHz.'''<br />
File: PointSrcMask_217.png | '''Point source mask, 217 GHz.'''<br />
File: PointSrcMask_353.png | '''Point source mask, 343 GHz.'''<br />
File: PointSrcMask_545.png | '''Point source mask, 545 GHz.'''<br />
File: PointSrcMask_857.png | '''Point source mask, 857 GHz.'''<br />
</gallery><br />
</center><br />
<br />
== File names ==<br />
The FITS filenames are of the form ''{H|L}FI_SkyMap_fff{-tag}_Nside_R3.nn_{coverage}-{type}.fits'', where "fff" are three digits to indicate the Planck frequency band, "tag" indicates the single detector or the detset (no "tag" indicates full channel), "Nside" is the HEALPix <i>N</i><sub>side</sub> value of the map, "coverage" indicates which part of the mission is covered (full, half mission, survey, year, etc.), and the optional "type" indicates the subset of input data used. The table below lists the products by type, with the appropriate unix wildcards that form the full filename.<br />
<br />
{| class="wikitable" align="center" style="text-align"left" border="1" cellpadding="15" cellspacing="20" width=880px<br />
|+ '''HFI FITS filenames'''<br />
|- bgcolor="ffdead"<br />
! Coverage || Filename <br />
|-<br />
| Full channel, full mission ||HFI_SkyMap_fff{-tag}_2048_R3.??_full.fits<br />
|-<br />
| Full channel, half mission || HFI_SkyMap_fff{-tag}_2048_R3.??_halfmission-{1/2}.fits<br />
|-<br />
| Full channel, full mission, odd/even ring || HFI_SkyMap_fff{-tag}_2048_R3.??_{odd/even}ring.fits <br />
|}<br />
<br />
{| class="wikitable" align="center" style="text-align"left" border="1" cellpadding="15" cellspacing="20" width=1600px<br />
|+ '''LFI FITS filenames'''<br />
|- bgcolor="ffdead"<br />
! Coverage || Filename || Half-ring filename || Comment<br />
|-<br />
| Full channel, full mission ||LFI_SkyMap_???_1024_R3.??_full.fits ||LFI_SkyMap_???_1024_R3.??_full-ringhalf-?.fits || 70GHz is corrected for Template<br />
|-<br />
| Full channel, full mission BandPass corrected ||LFI_SkyMap_???-BPassCorrected_1024_R3.??_full.fits ||LFI_SkyMap_???-BPassCorrected_???_1024_R3.??_full-ringhalf-?.fits || 70GHz is corrected for Template<br />
|-<br />
| Full channel, single survey || LFI_SkyMap_???_1024_R3.??_survey-?.fits || n/a || n/a<br />
|-<br />
| Full channel, survey combination || LFI_SkyMap_???_1024_R3.??_survey-1-3-5-6-7-8.fits || n/a || n/a<br />
|-<br />
| Full channel, survey combination BandPass corrected|| LFI_SkyMap_???_1024_R3.??-BPassCorrected_survey-1-3-5-6-7-8.fits || n/a || n/a<br />
|-<br />
| Full channel, single year || LFI_SkyMap_???_1024_R3.??_year-?.fits || n/a || n/a<br />
|-<br />
| Full channel, single year BandPass corrected|| LFI_SkyMap_???-BPassCorrected_1024_R3.??_year-?.fits || n/a || n/a<br />
|-<br />
| Full channel, year combination || LFI_SkyMap_???_1024_R3.??_year?-?.fits || n/a || n/a<br />
|-<br />
| Full channel, year combination BandPass corrected|| LFI_SkyMap_???-BPassCorrected_1024_R3.??_year?-?.fits || n/a || n/a<br />
|-<br />
| Horn pair, full mission || LFI_SkyMap_???-??-??_1024_R3.??_full.fits || LFI_SkyMap_???_??-??_1024_R3.??_full-ringhalf-?.fits || n/a<br />
|-<br />
| Single radiometer, full mission || LFI_SkyMap_???-???_1024_R3.??_full.fits || LFI_SkyMap_???-???_1024_R3.??_full-ringhalf-?.fits || n/a<br />
|}<br />
<br />
For the benefit of users who are only looking for the frequency maps with no additional information, we also provide a file combining the nine frequency maps as separate columns in a single extension. The nine columns in this file contain the intensity maps <i>only</i> and no other information (hits maps or variance maps) is provided.<br />
<br />
== FITS file structure ==<br />
<br />
The FITS files for the sky maps contain a minimal primary header with no data, and a ''BINTABLE'' extension (EXTENSION 1, EXTNAME = ''FREQ-MAP'') containing the data. The structure is shown schematically in the figure below. The ''FREQ-MAP'' extension contains a 3- or 10-column table that contain the signal, hit-count, and variance maps, all in HEALPix format. The 3-column case is for intensity only maps, while the 10-column case is for polarization. The number of rows is the number of map pixels, which is <i>N</i><sub>pix</sub> = 12 <i>N</i><sub>side</sub><sup>2</sup> for HEALPix maps, where <i>N</i><sub>side</sub> = 1024 or 2048 for most the maps presented in this section.<br />
<br />
[[File:FITS_FreqMap.png | 550px | center | thumb | '''FITS file structure.''']]<br />
<br />
Note that file sizes are approximately 0.6 GB for <i>I</i>-only maps and 1.9 GB for <i>IQU</i> maps at <i>N</i><sub>side</sub>=2048, but about 0.14 GB for <i>I</i>-only maps and 0.45 GB for <i>IQU</i> maps at <i>N</i><sub>pix</sub>=1024 .<br />
<br />
Keywords indicate the coordinate system ("GALACTIC"), the HEALPix ordering scheme ("NESTED"), the units (K<sub>CMB</sub> or MJy.sr<sup>-1</sup>) of each column, and of course the frequency channel ("FREQ"). Where polarization <i>Q</i> and <i>U</i> maps are provided, the "COSMO" polarization convention (used in HEALPix) is adopted, and it is specified in the "POLCCONV" keyword (see [[Sky_temperature_maps#Polarization_convention_used_in_the_Planck_project|this section]]). The "COMMENT" fields give a one-line summary of the product, and some other information useful for traceability within the DPCs. The original filename is also given in the "FILENAME" keyword. The "BAD_DATA" keyword gives the value used by HEALPix to indicate pixels for which no signal is present (these will also have a hit-count value of 0). The main parameters are summarized in the table below.<br />
<br />
{| border="1" cellpadding="3" cellspacing="0" align="center" style="text-align:left" width=800px<br />
|+ '''Sky map file data structure'''<br />
|- bgcolor="ffdead" <br />
!colspan="4" | 1. EXTNAME = 'FREQ-MAP' : Data columns<br />
|- bgcolor="ffdead" <br />
! Column name || Data type || Units || Description<br />
|-<br />
|I_STOKES || Real*4 || K<sub>CMB</sub> or MJy.sr<sup>-1</sup> || Stokes <i>I</i> map<br />
|-<br />
|Q_STOKES || Real*4 || K<sub>CMB</sub> or MJy.sr<sup>-1</sup> || Stokes <i>Q</i> map (optional)<br />
|-<br />
|U_STOKES || Real*4 || K<sub>CMB</sub> or MJy.sr<sup>-1</sup> || Stokes <i>U</i> map (optional)<br />
|-<br />
|HITS || Int*4 || none || The hit-count map<br />
|-<br />
|II_COV || Real*4 || K<sub>CMB</sub><sup>2</sup> or (MJy.sr<sup>-1</sup>)<sup>2</sup> || <i>II</i> variance map<br />
|-<br />
|IQ_COV || Real*4 || K<sub>CMB</sub><sup>2</sup> or (MJy.sr<sup>-1</sup>)<sup>2</sup> || <i>IQ</i> variance map (optional)<br />
|-<br />
|IU_COV || Real*4 || K<sub>CMB</sub><sup>2</sup> or (MJy.sr<sup>-1</sup>)<sup>2</sup> || <i>IQ</i> variance map (optional)<br />
|-<br />
|QQ_COV || Real*4 || K<sub>CMB</sub><sup>2</sup> or (MJy.sr<sup>-1</sup>)<sup>2</sup> || <i>QQ</i> variance map (optional)<br />
|-<br />
|QU_COV || Real*4 || K<sub>CMB</sub><sup>2</sup> or (MJy.sr<sup>-1</sup>)<sup>2</sup> || <i>QU</i> variance map (optional)<br />
|-<br />
|UU_COV || Real*4 || K<sub>CMB</sub><sup>2</sup> or (MJy.sr<sup>-1</sup>)<sup>2</sup> || <i>UU</i> variance map (optional)<br />
|-<br />
|- bgcolor="ffdead" <br />
! Keyword || Data type || Value || Description<br />
|-<br />
|PIXTYPE || String || HEALPIX ||<br />
|-<br />
|COORDSYS || String || GALACTIC ||Coordinate system <br />
|-<br />
|ORDERING || String || NESTED || Healpix ordering<br />
|-<br />
|POLCCONV || String || COSMO || Polarization convention<br />
|-<br />
|NSIDE || Int || 1024 or 2048 || HEALPix <i>N</i><sub>side</sub> <br />
|-<br />
|FIRSTPIX || Int*4 || 0 || First pixel number<br />
|-<br />
|LASTPIX || Int*4 || 12 <i>N</i><sub>side</sub><sup>2</sup> – 1 || Last pixel number<br />
|-<br />
|FREQ || String || nnn || Frequency channel <br />
|}<br />
<br />
<br />
The same structure applies to all "SkyMap" products, independent of whether they are full channel, survey of half-ring. The distinction between the types of maps is present in the FITS filename (and in the traceability comment fields).<br />
<br />
==Polarization convention used in the Planck project==<br />
<br />
The FITS keyword "POLCCONV" defines the polarization convention of the data within the file.<br />
The Planck collaboration used the COSMO convention for the polarization angle (as usually adopted in space-based and other CMB missions), whereas other subfields of astronomy usually adopt the IAU convention. The basic difference comes down to whether one thinks of the light rays being emitted from the origin (the usual mathematics/physics convention) or converging on the observer from the sky (the usual astronomy convention), and hence the "obvious" choice is different for a physicists and for an astronomer. Given that CMB results are of interest to a wide range of both physicists and astronomers, there is no single choice of convention that everyone would regard as self-evident. Hence one simply has to be aware of the convention being adopted. Because of this the Planck Collaboration has taken pains to point out which convention is being used in publications and in data releases. In the following we describe the difference between these two conventions, and the consequence if it is <i>not</i> taken into account correctly in the analysis.<br />
<br />
[[File:conventions.png|thumb|center|400px|'''Figure 1. Polarization conventions, showing the COSMO convention (left) and IAU convention (right). The vector <math>\hat{z}</math> points in the outward direction in COSMO, and inwards in IAU. The bottom panel refers to the plane tangent to the sphere.''']]<br />
<br />
Changing the orientation convention is equivalent to a transformation &psi;'=&pi;-&psi; of the polarization angle (Figure 1). The consequence of this transformation is the inversion of the Stokes parameter <i>U</i>.<br />
The components of the polarization tensor in the helicity basis <math>\epsilon^{\pm}=(\hat{x}\pm i\hat{y})/\sqrt{2}</math> are<br />
<br />
<math><br />
(Q+iU)(\hat{n}) = \sum _{\ell m}a_{2,lm}{}_{2}Y_{\ell }^{m}(\hat{n}),<br />
\\(Q-iU)(\hat{n}) = \sum _{\ell m}a_{-2,lm}{}_{2}Y_{\ell }^{m}(\hat{n}),<br />
</math><br />
<br />
where <math>{}_{2}Y_{\ell }^{m}(\hat{n})</math> are the spin-weighted spherical harmonic functions.<br />
The <i>E</i> and <i>B</i> modes can be defined as<br />
<br />
<math><br />
E(\hat{n}) = \sum_{\ell m}a_{E,\ell m}Y_{\ell }^{m}(\hat{n}),<br />
\\B(\hat{n}) = \sum_{\ell m}a_{B,\ell m}Y_{\ell }^{m}(\hat{n}),<br />
</math><br />
<br />
where the coefficients <i>a<sub>E,&#8467;m</sub></i> and <i>a<sub>B,&#8467;m</sub></i> are derived from linear combinations of the <i>a<sub>2,&#8467;m</sub></i>, <i>a<sub>-2,&#8467;m</sub></i>, defined implicitly in the first equation (<i>Q</i>&plusmn; i<i>U</i>).<br />
<br />
[[File:test_gradient.jpg|thumb|center|400px|]]<br />
[[File:test_curl.jpg|thumb|center|400px|'''Figure 2. Error on Planck-LFI 70 GHz <i>EE</i> (top) and <i>BB</i> (bottom) power spectra, in the case of an incorrect choice being made for the polarization coordinate system convention (IAU instead of COSMO).''']]<br />
<br />
The effect of the sign inversion of <i>U</i> on the polarization spectra is a non-trivial mixing of <i>E</i> and <i>B</i> modes. <br />
An example of the typical error on <i>EE</i> and <i>BB</i> auto-spectra in the case of the wrong choice for the polarization basis is shown in Figure 2.<br />
<br />
<i>One should be careful</i> to be aware of the polarization convention that is being adopted. If the IAU convention is used in computing the power spectra, then the sign of the <i>U</i> component of the Planck maps must be inverted before computing the <i>E</i> and <i>B</i> modes.<br />
<br />
In astronomical applications it is common to define a pseudo-vector <i>P</i> to show the amplitude and orientation of<br />
polarization on a map. When plotting these line segments to show the orientation of the plane of polarization (or the orthogonal direction, often considered to be the projection of the magnetic field), the results are the same for both the COSMO and IAU conventions. This because the appearance of <i>P</i> is a property of the radiation and hence not affected by the sign of <i>U</i>.<br />
<br />
=== Note on the convention used in the Planck Catalogue of Compact Sources (PCCS) ===<br />
Planck non-cosmology papers sometimes follow the IAU convention for internal analysis, for ease of comparison with other studies (e.g., comparison of Planck-derived thermal dust emission polarization with the optical polarization of starlight). Nevertheless, Planck data products, such as component-separated maps, still use the COSMO convention. The one exception is for the compact source catalogue. Because catalogues of astronomical objects found by Planck need to be compared directly with other source catalogues, the polarized sources described in the Planck Catalogue of Compact Sources follow the IAU convention, and the polarization angles are defined on an interval of [-90&deg;,90&deg;]. To switch to the COSMO convention, the polarization angles listed in the catalogue should be shifted by 90&deg; and multiplied by -1.<br />
<br />
== References ==<br />
<References /><br />
<br />
<br />
<span style="background:green"><br />
<br />
<span style="background:green"><br />
== Previous releases ==<br />
<br />
<div class="toccolours mw-collapsible mw-collapsed" style="background-color: #FFDAB9;width:80%" ><br />
'''2015 Sky temperature and polarization maps'''<br />
<br />
<div class="mw-collapsible-content"><br />
<br />
<br />
'''General description'''<br />
<br />
Sky maps give the best estimate of the intensity and polarization (Stokes Q and U components), if available, of the signal from the sky after removal, as far as possible, of known systematic effects (mostly instrumental, but including also the solar and earth-motion dipole, Galactic strylight and the Zodiacal light). Sky maps are provided for the full Planck mission using all valid detectors in each frequency channel, and also for various subsets by splitting the mission in various time ranges or in subsets of the detectors in a given channel. These products are useful for the study of source variability, but they are especially interesting for characterisation purposes (see also the [[HFI-Validation | data validation]] section). The details of the start and end of the time ranges are given in the table below.<br />
<br />
To help in further processing, there are also masks of the Galactic Plane and of point sources, each provided for several different depths.<br />
<br />
All sky maps are in Healpix format, with Nside of 1024 (LFI 30, 44 and 70) and 2048 (LFI 70 and HFI), in Galactic coordinates, and Nested ordering. <br />
<br />
;WARNING: the Healpix convention for polarization is NOT the same as the IAU convention - see Section 8 in this page.<br />
<br />
The signal is given in units of K<sub>cmb</sub> for 30-353 GHz, and of MJy/sr (for a constant <math>\nu F_\nu</math> energy distribution ) for 545 and 857 GHz. For each frequency channel, the intensity and polarization maps are packaged into a ''BINTABLE'' extension of a FITS file together with a hit-count map (or hit map, for short, giving the number of observation samples that are cumulated in a pixel, all detectors combined) and with the variance and covariance maps. Additional information is given in the FITS file header. The structure of the FITS file is given in the [[#FITS_file_structure | FITS file structure]] section below. <br />
<br />
; R2.00 : this first release (Jan 2015) contains polarisation data for the 353 GHz channel only.<br />
; R2.01 : this second release (May 2015) adds polarisation data to the 100-217 GHz channels.<br />
; R2.02 : a full re-release to correct the Healpix bad pixel value in the maps which was altered during the preparation of the maps and not reset to the correct value (the valid pixels are unchanged). It also fixes some FITS keywords, and includes a full re-release of the Zodi correction maps, with the 100-217 GHz one now including the polarisation correction)<br />
<br />
{| border="1" cellpadding="3" cellspacing="0" align="center" style="text-align:left" width=800px<br />
|+ '''Ranges for mission and surveys'''<br />
|- bgcolor="ffdead" <br />
! Range || ODs || HFI rings || pointing-IDs || Comment<br />
|-<br />
|nominal mission || 91 - 563 || 240 - 14723 || 00004200 - 03180200 ||<br />
|-<br />
|full mission || 91 - 974 || 240 - 27005 || 00004200 - 05322620 || for HFI<br />
|-<br />
|full mission || 91 - 1543 || n/a || 00004200 - 06511160 || for LFI<br />
|-<br />
|Survey 1 || 91 - 270 || 240 - 5720 || 00004200 - 01059820 ||<br />
|-<br />
|Survey 2 || 270 - 456 || 5721 - 11194 || 01059830 - 02114520 ||<br />
|-<br />
|Survey 3 || 456 - 636 || 11195 - 16691 || 02114530 - 03193660 ||<br />
|-<br />
|Survey 4 || 636 - 807 || 16692 - 21720 || 03193670 - 04243900 ||<br />
|-<br />
|Survey 5 || 807 - 974 || 21721 - 27005 || 05267180 - 05322590 || end of mission for HFI<br />
|-<br />
|Survey 5 || 807 - 993 || n/a || 05267180 - 06344800 || end of survey for LFI<br />
|-<br />
|Survey 6 || 993 - 1177 || n/a || 06344810 - 06398120 || LFI only <br />
|-<br />
|Survey 7 || 1177 - 1358 || n/a || 06398130 - 06456410 || LFI only <br />
|-<br />
|Survey 8 || 1358 - 1543 || n/a || 06456420 - 06511160 || LFI only <br />
|-<br />
|Survey 9 || 1543 - 1604 || n/a || 06511170 - 06533320 || LFI only Not in this delivery<br />
|-<br />
|HFI mission-half-1 || 91 - 531 || 240 - 13471 || 00004200 - 03155580 ||<br />
|-<br />
|HFI mission-half-2 || 531 - 974 || 13472 - 27005 || 03155590 - 05322590 ||<br />
|-<br />
|LFI Year 1 || 91 - 456 || n/a || 00004200 - 02114520 ||<br />
|-<br />
|LFI Year 2 || 456 - 807 || n/a || 02114530 - 04243900 ||<br />
|-<br />
|LFI Year 3 || 807 - 1177 || n/a || 05267180 - 06398120 ||<br />
|-<br />
|LFI Year 4 || 1177 - 1543 || n/a || 06398130 - 06511160 ||<br />
|-<br />
|}<br />
<br />
'''Production process'''<br />
<br />
Sky maps are produced by combining appropriately the data of all working detectors in a frequency channel over some period of the mission. They give the best estimate of the signal from the sky (unpolarised) after removal, as far as possible, of known systematic effects and of the dipole signals induced by the motion of the solar system in the CMB and of the Planck satellite in the solar system. In particular, they include the Zodiacal light emission (Zodi for short) and also the scattering from the far-side lobes of the beams (FSL). More on this below.<br />
<br />
''' HFI processing '''<br />
<br />
The mapmaking and calibration process is described in detail in the [[Map-making_LFI | Map-making]] section and in the {{PlanckPapers|planck2014-a09}} paper, where detailed references are found. In brief it consists of:<br />
<br />
; binning the TOI data onto ''rings'' : Healpix rings (HPRs) are used here, each ring containing the combined data of one pointing period. <br />
; flux calibration : at 100-353 GHz, the flux calibration factors are determined by correlating the signal with the orbital dipole, which is determined very accurately from the Planck satellite orbital parameters provided by Flight Dynamics. This provides a single gain factor per bolometer. At 545 and 857 GHz the gain is determined from the observation of Uranus and Neptune (but not Jupiter which is too bright) and comparison to recent models made explicitly for this mission. A single gain is applied to all rings at these frequencies.<br />
; destriping : in order to remove low-frequency noise, an offset per ring is determined by minimizing the differences between HPRs at their crossings, and removed.<br />
; Zodiacal light correction : a Zodiacal light model is used to build HPRs of the the Zodi emission, which is subtracted from the calibrated HPRs.<br />
; projection onto the map : the offset-corrected, flux-calibrated, and Zodi-cleaned HPRs are projected onto Healpix maps, with the data of each bolometer weighted by a factor of 1/NET of that bolometer.<br />
<br />
These steps are followed by some post-processing which is designed to prepare the maps for the component separation work. This post processing consists of: <br />
<br />
; Dust bandpass leakage correction : the Q and U maps are corrected for the intensity-to-polarisation leakage caused by the foregrounds having a non-CMB spectrum, and as a consequence of the non-identical bandpasses on the different detectors (bandpass mismatch, or BPM). This correction is determined using the ''ground'' method as described in Section 7.3 of {{PlanckPapers|planck2014-a09}}. These correction maps can be found in the Planck Legacy Archive as ''HFI_CorrMap_???-dustleak-ground_2048_R2.0?_{coverage}.fits''. The correction is applied by subtracting the correction map from the corresponding input map. This correction is not applied to the nominal mission maps in order to maintain compatibility with the PR1 products. ''In fact this correction was computed and applied only to the products used in component separation'', so they were not applied to the single survey maps and to the half-ring maps, which are considered characterisation products.<br />
; Far Side Lobe calibration correction : the 100-217 maps are multiplied by factors of 1.00087, 1.00046, and 1.00043, respectively, to compensate for the non-removal of the far-side lobes, and similarly the corresponding covariance maps have also been corrected by multiplication by the square of the factor.<br />
; Fill missing pixels : missing pixels are filled in with a value that is the mean of valid pixels within a given radius. A radius of 1 deg is used for the full channel maps, and 1.5 deg is used for the detset maps. This step is not applied to the single survey maps since they have large swaths of the sky that are not covered.<br />
<br />
; Map zero-level : for the 100 to 857 GHz maps, the zero levels are set to their optimal levels for Galactic and CIB studies. A procedure for adjusting them to astrophysical values is given in the HFI Mapmaking and Calibration paper {{PlanckPapers|planck2014-a09}}.<br />
<br />
These maps provide the main mission products. Together with signal maps, hit count, variance, and variance maps are also produced. The hit maps give the (integer) number of valid TOI-level samples that contribute to the signal of each pixel. All valid samples are counted in the same way, i.e., there is no weighting factor applied. The variance maps project the white noise estimate, provided by the NETs, in the sky domain.<br />
<br />
Note that the nominal mission maps have not had the post-processing applied, which makes them more easily comparable to the PR1 products.<br />
<br />
''' LFI processing '''<br />
LFI maps were constructed with the Madam map-making code, version 3.7.4. The code is based on generalized destriping technique, where the correlated noise component is modeled as a sequence of constant offset, called baselines. A noise filter was used to constrain the baseline solution allowing the use of 0.25 s and 1 second baselines for the 30 and 44, 70 GHz respectively.<br />
<br />
Radiometers were combined according to the horn-uniform weighting scheme to minimize systematics. The used weights are listed in [[Map-making LFI#Map-making|Map-making]]. The flagged samples were excluded from the analysis by setting their weights to <math>C_{w}^{-1}</math> = 0. The galaxy region was masked out in the destriping phase, to reduce error arising from strong signal gradients. The polarization component was included in the analysis... <br />
<br />
; Dipole and Far Side Lobe correction : input timelines are cleaned by 4pi convolved dipole and Galactic Straylight obtained as convolution of the 4pi in band far sidelobes and Galactic Simulation as explained in Section 7.4 of {{PlanckPapers|planck2014-a03}}. <br />
<br />
Beam effects on the LFI maps are described in Section 7.1 of {{PlanckPapers|planck2014-a03}}. Scaling of the maps due to beam effects is taken into account in the LFI's beam functions (as provided in the RIMO, give reference) which should be used for analysis of diffuse components. To compute the flux densities of compact sources, correction must be made for beam effects (see Table 8 of {{PlanckPapers|planck2014-a03}})."<br />
<br />
; Bandpass leakage correction : '''as opposed to the HFI, the LFI high resolution maps have not been corrected for bandpass leakage. Only low resolution (nside 256) maps are provided with the bandpass correction'''. The correction maps (LFI_CorrMap_0??-BPassCorr_*.fits) can be found in the Planck Legacy Archive. Further details about the procedure used to generate the bandpass correction maps can be found in Section 11 of {{PlanckPapers|planck2014-a03}}.<br />
<br />
; Map zero-level : for the 30, 44 and 70 GHz, maps are corrected for zero level monopole by applying an offset correction, see LFI Calibration paper {{PlanckPapers|planck2014-a06}}. Note that the offset applied is indicated in the header as a comment keyword.<br />
<br />
A detailed description of the map-making procedure is given in {{PlanckPapers|planck2013-p02}}, {{PlanckPapers|planck2014-a03}}, {{PlanckPapers|planck2014-a07}} and in section [[Map-making LFI#Map-making|Map-making]].<br />
<br />
'''Types of maps '''<br />
<br />
''' Full mission, full channel maps (6 HFI, 4 LFI)'''<br />
<br />
Full channel maps are built using all the valid detectors of a frequency channel and cover the either the full or the nominal mission. For HFI, the 143-8 and 545-3 bolometers are rejected entirely as they are seriously affected by RTS noise. HFI provides the Q and U components for the 100, 143, 217 and 353 GHz channels only. LFI provides the I, Q and U maps for all the channels. Reminder: HFI Q and U maps are corrected for bandpass leakage but LFI Q and U maps are not. The I, Q and U maps are displayed in the figures below. The color range is set using a histogram equalisation scheme (from HEALPIX) that is useful for these non-Gaussian data fields. For visualization purposes, the Q and U maps shown here have been smoothed with a 1 degree Gaussian kernel, otherwise they look like noise to the naked eye.<br />
The 70 GHz full map is available also at <math>N_{side}</math> 2048.<br />
<br />
<center><br />
<gallery style="padding:0 0 0 0;" perrow=3 widths=260px heights=160px> <br />
File: SkyMap30e.png| '''Full mission I, 30 GHz'''<br />
File: SkyMap44e.png | '''Full mission I, 44 GHz'''<br />
File: SkyMap70e.png | '''Full mission I, 70 GHz'''<br />
File: SkyMap100e.png | '''Full mission I, 100 GHz'''<br />
File: SkyMap143e.png | '''Full mission I, 143 GHz'''<br />
File: SkyMap217e.png | '''Full mission I, 217 GHz'''<br />
File: SkyMap353e.png | '''Full mission I, 353 GHz'''<br />
File: SkyMap545e.png | '''Full mission I, 545 GHz'''<br />
File: SkyMap857e.png | '''Full mission I, 857 GHz'''<br />
</gallery><br />
</center><br />
<br><br />
<center><br />
<gallery style="padding:0 0 0 0;" perrow=3 widths=260px heights=160px> <br />
File: LFI_SkyMap_030_1024_R2.01_full_Qb_sm1deg.png| '''Full mission Q, 30 GHz'''<br />
File: LFI_SkyMap_044_1024_R2.01_full_Qb_sm1deg.png | '''Full mission Q, 44 GHz'''<br />
File: LFI_SkyMap_070_1024_R2.01_full_Qb_sm1deg.png | '''Full mission Q, 70 GHz'''<br />
File: HFI_Skymap_100_full_bplcorrected_sm1deg_Qb.png | '''Full mission Q, 100 GHz'''<br />
File: HFI_Skymap_143_full_bplcorrected_sm1deg_Qb.png | '''Full mission Q, 143 GHz'''<br />
File: HFI_Skymap_217_full_bplcorrected_sm1deg_Qb.png | '''Full mission Q, 217 GHz'''<br />
File: HFI_Skymap_353_full_bplcorrected_sm1deg_Qb.png | '''Full mission Q, 353 GHz'''<br />
</gallery><br />
</center><br />
<br><br />
<center><br />
<gallery style="padding:0 0 0 0;" perrow=3 widths=260px heights=160px> <br />
File: LFI_SkyMap_030_1024_R2.01_full_Ub_sm1deg.png| '''Full mission U, 30 GHz'''<br />
File: LFI_SkyMap_044_1024_R2.01_full_Ub_sm1deg.png | '''Full mission U, 44 GHz'''<br />
File: LFI_SkyMap_070_1024_R2.01_full_Ub_sm1deg.png | '''Full mission U, 70 GHz'''<br />
File: HFI_Skymap_100_full_bplcorrected_sm1deg_Ub.png | '''Full mission U, 100 GHz'''<br />
File: HFI_Skymap_143_full_bplcorrected_sm1deg_Ub.png | '''Full mission U, 143 GHz'''<br />
File: HFI_Skymap_217_full_bplcorrected_sm1deg_Ub.png | '''Full mission U, 217 GHz'''<br />
File: HFI_Skymap_353_full_bplcorrected_sm1deg_Ub.png | '''Full mission U, 353 GHz'''<br />
</gallery><br />
<br />
</center><br />
<br />
''' Full mission light maps, full channel maps (6 HFI, 7 LFI) '''<br />
<br />
These maps are based on the Full mission maps but contain fewer columns, IQU from 30 to 353 GHz, and I only at 545 and 857 GHz. These maps have been produced to reduce the transfer time of the most downloaded frequency full mission maps.<br />
<br />
''' Nominal mission, full channel maps (6 HFI) '''<br />
<br />
These maps are similar to the ones above, but cover the nominal mission only. They are meant primarily to be compared to the PR1 products in order to see the level of improvements in the processing. Because of this, they are produced in Temperature only, and have not had the post-processing applied.<br />
<br />
''' Single survey, full channel maps (30 HFI, 35 LFI)'''<br />
<br />
Single survey maps are built using all valid detectors of a frequency channel; they cover separately the different sky surveys. The surveys are defined as the times over which the satellite spin axis rotates but 180 degrees, which, due to the position of the detectors in the focal plane does not cover the full sky, but a fraction between ~80 and 90% depending on detector position. During adjacent surveys the sky is scanned in opposite directions. More precisely it is the ecliptic equator that is scanned in opposite directions. While these are useful to investigate variable sources, they are also used to study the systematics of the time-response of the detectors as they scan bright sources, like the Galactic Plane, in different directions during different survey. Note that the HFI and LFI missions cover 5 and 8 surveys, respectively, and in case of HFI the last survey in incomplete.<br />
The 70 GHz surveys maps are available also at <math>N_{side}</math> 2048.<br />
Note LFI provide a special surveys maps combination used in the low l analysis. This maps, available at the three LFI frequency 30, 44 and 70 GHz, was built using the combination of survey 1, 3, 5, 6, 7 and 8. <br />
<br />
''' Year maps, full channel maps (12 HFI, 16 LFI)'''<br />
<br />
These maps are built using the data of surveys 1+2, surveys 3+4, and so forth. They are used to study long-term systematic effects.<br />
The 70 GHz years maps are available also at <math>N_{side}</math> 2048.<br />
<br />
'''Half-mission maps, full channel maps (12 HFI, 12 LFI)'''<br />
<br />
For HFI, the half mission is defined after eliminating those rings discarded for all bolometers. There are 347 such rings, may of which are during the 5th survey when the ''End-of-Life'' tests were performed. The remaining 26419 rings are divided in half (up to the odd ring) to define the two halves of the mission. This exercise is done for the full mission only.<br />
<br />
For LFI instead of the half-mission the following year combination has been created: Year 1+2, Year 1+3, Year 2+4, Year 3+4, <br />
<br />
'''Full mission, single detector maps (18 HFI, 22 LFI)'''<br />
<br />
IN case of HFI these maps are built only for the SWBs (non polarized) and contain only temperature data, of course. They are not built for the polarisation sensitive detectors because they are not fixed on the sky as the polarisation component depends on the position angle at the time of observation. Instead, we provide maps built by ''quads'' of polarisation-sensitive detectors (see next section), which have different polarisation angles and that can be used to built I, Q, and U maps<br />
<br />
{| border="1" cellpadding="3" cellspacing="0" align="center" style="text-align:left" width=600px<br />
|+ '''HFI Temperature sensitive bolometers'''<br />
|- bgcolor="ffdead" <br />
!Frequency || Detector names<br />
|-<br />
|143 GHz || 143-5, 6, 7<br />
|-<br />
|217 GHz || 217-1, 2, 3, 4<br />
|-<br />
|353 GHz || 353-1, 2, 7, 8<br />
|-<br />
|545 GHz || 545-1, 2, 4<br />
|-<br />
|857 GHz || 857-1, 2 , 3, 4<br />
|}<br />
<br />
The 143-8 and 353-3 bolometer data are affected by strong RTS (random telegraphic signal) noise. They have not been used in the data processing, and are not delivered. For a figure showing the focal plane layout, see [[Detector_pointing#Introduction_and_Summary | this Introduction]] of the Detector Pointing chapter.<br />
<br />
In case of LFI, all the 22 Radiometers maps are available, those, obviously, are only in temperature.<br />
<br />
'''Full mission, detector set or detector pairs maps (8 HFI, 8 LFI)'''<br />
<br />
The objective here is to build independent temperature (I) and polarisation (Q and U) maps with the two pairs of polarisation sensitive detectors of each channel where they are available, i.e. in the 44-353 GHz channels. The table below indicates which detectors were used to built each detector set (detset).<br />
<br />
<br />
{| border="1" cellpadding="3" cellspacing="0" align="center" style="text-align:left" width=600px<br />
|+ '''Definition of HFI Detector Sets'''<br />
|- bgcolor="ffdead" <br />
!Frequency || DetSet1 || DetSet2 <br />
|-<br />
|100 GHz || 100-1a/b & 100-4a/b || 100-2a/b & 100-3a/b<br />
|-<br />
|143 GHz || 143-1a/b 1 & 43-3a/b || 143-2a/b & 143-4a/b<br />
|-<br />
|217 GHz || 217-5a/b & 217-7a/b || 217-6a/b & 217-8a/b<br />
|-<br />
|353 GHz || 353-3a/b & 353-5a/b || 353-4a/b & 353-6a/b<br />
|}<br />
<br />
{| border="1" cellpadding="3" cellspacing="0" align="center" style="text-align:left" width=600px<br />
|+ '''Definition of LFI Detector Pairs'''<br />
|- bgcolor="ffdead" <br />
!Frequency || Horn Pair || Comment <br />
|-<br />
|44 GHz || 24 || This maps is only in temperature<br />
|-<br />
|44 GHz || 25 & 26 || <br />
|-<br />
|70 GHz || 18 & 23 || Available also at <math>N_{side}</math> = 2048<br />
|-<br />
|70 GHz || 19 & 22 || Available also at <math>N_{side}</math> = 2048<br />
|-<br />
|70 GHz || 20 & 21 || Available also at <math>N_{side}</math> = 2048<br />
|}<br />
<br />
<br />
'''Half-ring maps (64 HFI, 62 LFI)'''<br />
<br />
These maps are similar to the ones above, but are built using only the first or the second half of each ring (or pointing period). The HFI provides half-ring maps for the full mission only, and for the full channel, the detsets, and the single bolometers. The LFI provides half-rings maps for the channel full mission (70 GHz also at <math>N_{side}</math> 2048), for the radiometer full mission and the horn pairs full mission.<br />
<!----<br />
'''Masks'''<br />
<br />
Masks are provided of the Galactic Plane and of the point sources. For the Galactic Plane, eight masks are given covering different fractions of the sky, and for the points sources two masks are given, at the 5 and 10 sigma level, for each Planck HFI and LFI frequency channel. These are generic masks, specific masks applicable to other products are delivered with the products themselves.<br />
---><br />
<br />
''' The Zodiacal light correction maps '''<br />
<br />
The Zodiacal light signal depends on the location of the observer relative to the Zodiacal light bands, and thus it is not a fixed pattern on the sky but depends on the period of observation. The maps presented here are the difference between the uncorrected (and not delivered) and the corrected maps. <br />
<br />
Note that while the Zodiacal light model that is subtracted at ring level (see [[Map-making#Zodiacal_light_correction | here]]) is not polarised, the corrections are not null and Q and U. This is suspected to come from some combination of leakage due to bandpass differences and beam mismatch, and maybe other effects. These leakages are typically of order a few %, at max, of the maximum zodi intensity at I for each channel. They range from ~150 nK at 100 GHz to ~5 uK at 353 GHz.<br />
<br />
''' Caveats and known issues '''<br />
<br />
; HFI polarization 100-217 GHz : at low multipoles, despite the progress that has been made to control the systematic effects present in the maps, polarization data between 100-217 GHz are still contaminated by systematic residuals. Figure 10 of {{PlanckPapers|planck2014-a09}} shows the EE power spectra from the half-difference maps at 100, 143, and 217 GHz and compared to the noise power spectrum from FFP8 simulations. he half-ring differences are compatible with noise while, at multipoles typically lower than 50, detector-set and half-mission differences are dominated by excess power which is larger than the EE CMB signal. The Planck Collaboration has used the range ell>30 to carry out component separation ({{PlanckPapers|planck2014-a11}}), as data at ell<30 is not considered usable for cosmological analyses. The origin of the excess power will be explored in a forthcoming publication.<br />
<br />
<br />
'''Inputs'''<br />
''' HFI inputs '''<br />
<br />
The HFI mapmaking takes as input:<br />
* the cleaned TOIs of signal of each detector, together with their flags, produced by the [[TOI processing|TOI processing]] pipeline;<br />
* the TOIs of pointing (quaternions), described in [[Detector_pointing|Detector pointing]];<br />
* bolometer-level characterization data, from the DPC's internal IMO (not distributed);<br />
* Planck orbit data, used to compute and remove the Earth's dipole;<br />
* Planck solar dipole information, used to calibrate the CMB channels;<br />
* Planet models used to calibrate the Galactic channels.<br />
<br />
''' LFI inputs '''<br />
<br />
The Madam mapmaker takes as input:<br />
<br />
* the calibrated timelines (for details see [[TOI processing LFI|TOI Processing]]);<br />
* the detector pointings (for details see [[Detector_pointing|Detector pointing]]);<br />
* the noise information in the form of 3-parameter (white noise level, &sigma;, slope, and knee frequency, <i>f</i><sub>knee</sub>) noise model (for details see [[The RIMO|RIMO]])<br />
<br />
'''Related products'''<br />
''' Masks '''<br />
<br />
This section presents the masks of the point sources and of the Galactic plane. These are ''general purpose'' masks. Other masks specific to certain products are packaged with the products.<br />
<br />
'''Point source masks'''<br />
<br />
For HFI and LFI two sets of masks are provided: <br />
* Intensity masks, which removes sources detected with SNR > 5. <br />
* Polarisation masks, which remove sources which have polarisation detection significance of 99.97 % or greater at the position of a source detected in intensity. They were derived from the polarisation maps with dust ground bandpass mismatch leakage correction applied. The cut around each source has a radius of 3σ (width) of the beam ~ 1.27 FWHM (for LFI the cut around each source has a radius of 32 arcmin at 30GHz, 27 arcmin at 44 GHz and 13 arcmin at 70 GHz).<br />
<br />
Both sets are found in the files ''HFI_Mask_PointSrc_2048_R2.00.fits'' and ''LFI_Mask_PointSrc_2048_R2.00.fits'' in which the first extension contains the Intensity masks, and the second contains the Polarisation masks.<br />
<br />
'''Galactic plane masks'''<br />
<br />
Eight masks are provided giving 20, 40, 60, 70, 80, 90, 97, and 99% sky coverage derived from the 353 GHz map, after CMB subtraction. They are independent of frequency channel. Three versions of these are given: not apodized, and apodized by 2 and 5 deg. The filenames are ''HFI_Mask_GalPlane-apoN_2048_R2.00.fits'', where N = 0, 2, 5.<br />
<br />
The masks are shows below. The 8 GalPlane masks are combined (added together) and shown in a single figure for each of the three apodization. While the result is quite clear for the case of no apodization, it is less so for the apodized case. The point source masks are shown separately for the Intensity case.<br />
<br />
<center><br />
<gallery perrow=3 widths=260px heights=160px ><br />
File: GalPlaneMask_apo0.png | '''Galactic Plane masks, no apod'''<br />
File: GalPlaneMask_apo2.png | '''Galactic Plane masks, apod 2 deg'''<br />
File: GalPlaneMask_apo5.png | '''Galactic Plane masks, apod 5 deg'''<br />
File: PointSrcMask_100.png | '''PointSource mask 100 GHz'''<br />
File: PointSrcMask_143.png | '''PointSource mask 143 GHz'''<br />
File: PointSrcMask_217.png | '''PointSource mask 217 GHz'''<br />
File: PointSrcMask_353.png | '''PointSource mask 343 GHz'''<br />
File: PointSrcMask_545.png | '''PointSource mask 545 GHz'''<br />
File: PointSrcMask_857.png | '''PointSource mask 857 GHz'''<br />
</gallery><br />
</center><br />
<br />
''' File names '''<br />
The FITS filenames are of the form ''{H|L}FI_SkyMap_fff{-tag}_Nside_R2.nn_{coverage}-{type}.fits'', where ''fff'' are three digits to indicate the Planck frequency band, ''tag'' indicates the single detector or the detset, ''Nside'' is the Healpix Nside of the map, ''coverage'' indicates which part of the mission is covered (full, half mission, survey, year, ...) , and the optional ''type'' indicates the subset of input data used. The table below lists the products by type, with the appropriate unix wildcards that form the full filename.<br />
<br />
{| class="wikitable" align="center" style="text-align"left" border="1" cellpadding="15" cellspacing="20" width=880px<br />
|+ '''HFI FITS filenames'''<br />
|- bgcolor="ffdead"<br />
! Coverage || filename || half-ring filename <br />
|-<br />
| Full chan, full mission ||HFI_SkyMap_???_2048_R2.??_full.fits ||HFI_SkyMap_???_2048_R2.??_full-ringhalf-?.fits<br />
|-<br />
| Full channel, nominal mission ||HFI_SkyMap_???_2048_R2.??_nominal.fits || n/a<br />
|-<br />
| Full channel, single survey || HFI_SkyMap_???_2048_R2.??_survey-?.fits || n/a<br />
|-<br />
| Full channel, single year || HFI_SkyMap_???_2048_R2.??_year-?.fits || n/a<br />
|-<br />
| Full channel, half mission || HFI_SkyMap_???_2048_R2.??_halfmission*-?.fits || n/a<br />
|-<br />
| Det-set, full mission || HFI_SkyMap_???-ds?_2048_R2.??_full.fits || HFI_SkyMap_???-ds?_2048_R2.??_full-ringhalf-?.fits<br />
|-<br />
|Single SWB, full mission || HFI_SkyMap_???-?_2048_R2.??_full.fits || HFI_SkyMap_???-?_2048_R2.??_full-ringhalf-?.fits<br />
|}<br />
<br />
{| class="wikitable" align="center" style="text-align"left" border="1" cellpadding="15" cellspacing="20" width=1000px<br />
|+ '''LFI FITS filenames'''<br />
|- bgcolor="ffdead"<br />
! Coverage || filename || half-ring filename || Comment<br />
|-<br />
| Full channel, full mission ||LFI_SkyMap_???_1024_R2.??_full.fits ||LFI_SkyMap_???_1024_R2.??_full-ringhalf-?.fits || Available also at Nside = 2048<br />
|-<br />
| Full channel, single survey || LFI_SkyMap_???_1024_R2.??_survey-?.fits || n/a || Available also at Nside = 2048<br />
|-<br />
| Full channel, survey combination || LFI_SkyMap_???_1024_R2.??_survey-1-3-5-6-7-8.fits || n/a || n/a<br />
|-<br />
| Full channel, single year || LFI_SkyMap_???_1024_R2.??_year-?.fits || n/a || Available also at Nside = 2048<br />
|-<br />
| Full channel, year combination || LFI_SkyMap_???_1024_R2.??_year?-?.fits || n/a || n/a<br />
|-<br />
| Horn pair, full mission || LFI_SkyMap_???-??-??_1024_R2.??_full.fits || LFI_SkyMap_???_??-??_1024_R2.??_full-ringhalf-?.fits || Available also at Nside = 2048<br />
|-<br />
| Single radiometer, full mission || LFI_SkyMap_???-???_1024_R2.??_full.fits || LFI_SkyMap_???-???_1024_R2.??_full-ringhalf-?.fits || n/a<br />
|}<br />
<br />
<br />
<br />
For the benefit of users who are only looking for the frequency maps with no additional information, we also provide a file combining the 9 frequency maps as separate columns in a single extension. The 9 columns in this file contain the intensity maps ONLY and no other information (hit maps and variance maps) is provided.<br />
<br />
<!---<br />
{| class="wikitable" align="center" style="text-align:center" border="1" cellpadding="3" cellspacing="0" width=500px<br />
|+ '''FITS filenames'''<br />
|- bgcolor="ffdead"<br />
! Frequency || Full channel maps<br />
|-<br />
| '''30GHz''' || {{PLASingleFile|fileType=map|name=LFI_SkyMap_030_1024_R1.10_nominal.fits|link=LFI_SkyMap_030_1024_R1.10_nominal.fits}}<br />
|-<br />
| '''44GHz''' || {{PLASingleFile|fileType=map|name=LFI_SkyMap_044_1024_R1.10_nominal.fits|link=LFI_SkyMap_044_1024_R1.10_nominal.fits}}<br />
|-<br />
| '''70GHz''' || {{PLASingleFile|fileType=map|name=LFI_SkyMap_070_1024_R1.10_nominal.fits|link=LFI_SkyMap_070_1024_R1.10_nominal.fits}}<br />
|-<br />
| '''70GHz''' || {{PLASingleFile|fileType=map|name=LFI_SkyMap_070_2048_R1.10_nominal.fits|link=LFI_SkyMap_070_2048_R1.10_nominal.fits}}<br />
|-<br />
| '''100GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_100_2048_R1.10_nominal.fits|link=HFI_SkyMap_100_2048_R1.10_nominal.fits}}<br />
|-<br />
| '''143GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_143_2048_R1.10_nominal.fits|link=HFI_SkyMap_143_2048_R1.10_nominal.fits}}<br />
|-<br />
| '''217GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_217_2048_R1.10_nominal.fits|link=HFI_SkyMap_217_2048_R1.10_nominal.fits}}<br />
|-<br />
| '''353GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_353_2048_R1.10_nominal.fits|link=HFI_SkyMap_353_2048_R1.10_nominal.fits}}<br />
|-<br />
| '''545GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_545_2048_R1.10_nominal.fits|link=HFI_SkyMap_545_2048_R1.10_nominal.fits}}<br />
|-<br />
| '''857GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_857_2048_R1.10_nominal.fits|link=HFI_SkyMap_857_2048_R1.10_nominal.fits}}<br />
|- bgcolor="ffdead"<br />
! Frequency || Full channel, Zodi-corrected maps<br />
|-<br />
| '''100GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_100_2048_R1.10_nominal_ZodiCorrected.fits|link=HFI_SkyMap_100_2048_R1.10_nominal_ZodiCorrected.fits}} <br />
|-<br />
| '''143GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_143_2048_R1.10_nominal_ZodiCorrected.fits|link=HFI_SkyMap_143_2048_R1.10_nominal_ZodiCorrected.fits}}<br />
|-<br />
| '''217GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_217_2048_R1.10_nominal_ZodiCorrected.fits|link=HFI_SkyMap_217_2048_R1.10_nominal_ZodiCorrected.fits}}<br />
|-<br />
| '''353GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_353_2048_R1.10_nominal_ZodiCorrected.fits|link=HFI_SkyMap_353_2048_R1.10_nominal_ZodiCorrected.fits}}<br />
|-<br />
| '''545GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_545_2048_R1.10_nominal_ZodiCorrected.fits|link=HFI_SkyMap_545_2048_R1.10_nominal_ZodiCorrected.fits}}<br />
|-<br />
| '''857GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_857_2048_R1.10_nominal_ZodiCorrected.fits|link=HFI_SkyMap_857_2048_R1.10_nominal_ZodiCorrected.fits}}<br />
|- bgcolor="ffdead"<br />
! Frequency || Combined frequency maps<br />
|-<br />
| '''All''' || {{PLASingleFile|fileType=file|name=COM_MapSet_I-allFreqs_R1.10_nominal.fits|link=COM_MapSet_I-allFreqs_R1.10_nominal.fits}} <br />
|}<br />
<br />
<br />
{| class="wikitable" align="center" style="text-align:center" border="1" cellpadding="3" cellspacing="0" width=850px<br />
|+ '''FITS filenames'''<br />
|- bgcolor="ffdead"<br />
! Frequency || Survey 1 maps || Survey 2 maps<br />
|-<br />
| '''30GHz''' || {{PLASingleFile|fileType=map|name=LFI_SkyMap_030_1024_R1.10_survey_1.fits|link=LFI_SkyMap_030_1024_R1.10_survey_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=LFI_SkyMap_030_1024_R1.10_survey_2.fits|link=LFI_SkyMap_030_1024_R1.10_survey_2.fits}}<br />
|-<br />
| '''44GHz''' || {{PLASingleFile|fileType=map|name=LFI_SkyMap_044_1024_R1.10_survey_1.fits|link=LFI_SkyMap_044_1024_R1.10_survey_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=LFI_SkyMap_044_1024_R1.10_survey_2.fits|link=LFI_SkyMap_044_1024_R1.10_survey_2.fits}}<br />
|-<br />
| '''70GHz''' || {{PLASingleFile|fileType=map|name=LFI_SkyMap_070_1024_R1.10_survey_1.fits|link=LFI_SkyMap_070_1024_R1.10_survey_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=LFI_SkyMap_070_1024_R1.10_survey_2.fits|link=LFI_SkyMap_070_1024_R1.10_survey_2.fits}}<br />
|-<br />
| '''70GHz''' || {{PLASingleFile|fileType=map|name=LFI_SkyMap_070_2048_R1.10_survey_1.fits|link=LFI_SkyMap_070_2048_R1.10_survey_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=LFI_SkyMap_070_2048_R1.10_survey_2.fits|link=LFI_SkyMap_070_2048_R1.10_survey_2.fits}}<br />
|-<br />
| '''100GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_100_2048_R1.10_survey_1.fits|link=HFI_SkyMap_100_2048_R1.10_survey_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_100_2048_R1.10_survey_2.fits|link=HFI_SkyMap_100_2048_R1.10_survey_2.fits}}<br />
|-<br />
| '''143GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_143_2048_R1.10_survey_1.fits|link=HFI_SkyMap_143_2048_R1.10_survey_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_143_2048_R1.10_survey_2.fits|link=HFI_SkyMap_143_2048_R1.10_survey_2.fits}}<br />
|-<br />
| '''217GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_217_2048_R1.10_survey_1.fits|link=HFI_SkyMap_217_2048_R1.10_survey_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_217_2048_R1.10_survey_2.fits|link=HFI_SkyMap_217_2048_R1.10_survey_2.fits}}<br />
|-<br />
| '''353GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_353_2048_R1.10_survey_1.fits|link=HFI_SkyMap_353_2048_R1.10_survey_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_353_2048_R1.10_survey_2.fits|link=HFI_SkyMap_353_2048_R1.10_survey_2.fits}}<br />
|-<br />
| '''545GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_545_2048_R1.10_survey_1.fits|link=HFI_SkyMap_545_2048_R1.10_survey_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_545_2048_R1.10_survey_2.fits|link=HFI_SkyMap_545_2048_R1.10_survey_2.fits}}<br />
|-<br />
| '''857GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_857_2048_R1.10_survey_1.fits|link=HFI_SkyMap_857_2048_R1.10_survey_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_857_2048_R1.10_survey_2.fits|link=HFI_SkyMap_857_2048_R1.10_survey_2.fits}}<br />
|- bgcolor="ffdead"<br />
! Frequency || Survey 1 Zodi-corrected maps || Survey 2 Zodi-corrected maps<br />
|-<br />
| '''100GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_100_2048_R1.10_survey_1_ZodiCorrected.fits|link=HFI_SkyMap_100_2048_R1.10_survey_1_ZodiCorrected.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_100_2048_R1.10_survey_2_ZodiCorrected.fits|link=HFI_SkyMap_100_2048_R1.10_survey_2_ZodiCorrected.fits}}<br />
|-<br />
| '''143GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_143_2048_R1.10_survey_1_ZodiCorrected.fits|link=HFI_SkyMap_143_2048_R1.10_survey_1_ZodiCorrected.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_143_2048_R1.10_survey_2_ZodiCorrected.fits|link=HFI_SkyMap_143_2048_R1.10_survey_2_ZodiCorrected.fits}}<br />
|-<br />
| '''217GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_217_2048_R1.10_survey_1_ZodiCorrected.fits|link=HFI_SkyMap_217_2048_R1.10_survey_1_ZodiCorrected.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_217_2048_R1.10_survey_2_ZodiCorrected.fits|link=HFI_SkyMap_217_2048_R1.10_survey_2_ZodiCorrected.fits}}<br />
|-<br />
| '''353GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_353_2048_R1.10_survey_1_ZodiCorrected.fits|link=HFI_SkyMap_353_2048_R1.10_survey_1_ZodiCorrected.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_353_2048_R1.10_survey_2_ZodiCorrected.fits|link=HFI_SkyMap_353_2048_R1.10_survey_2_ZodiCorrected.fits}}<br />
|-<br />
| '''545GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_545_2048_R1.10_survey_1_ZodiCorrected.fits|link=HFI_SkyMap_545_2048_R1.10_survey_1_ZodiCorrected.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_545_2048_R1.10_survey_2_ZodiCorrected.fits|link=HFI_SkyMap_545_2048_R1.10_survey_2_ZodiCorrected.fits}}<br />
|-<br />
| '''857GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_857_2048_R1.10_survey_1_ZodiCorrected.fits|link=HFI_SkyMap_857_2048_R1.10_survey_1_ZodiCorrected.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_857_2048_R1.10_survey_2_ZodiCorrected.fits|link=HFI_SkyMap_857_2048_R1.10_survey_2_ZodiCorrected.fits}}<br />
|- bgcolor="ffdead"<br />
! Frequency || Half-ring 1 maps ||Half-ring 2 maps<br />
|-<br />
| '''30GHz''' || {{PLASingleFile|fileType=map|name=LFI_SkyMap_030_1024_R1.10_nominal_ringhalf_1.fits|link=LFI_SkyMap_030_1024_R1.10_nominal_ringhalf_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=LFI_SkyMap_030_1024_R1.10_nominal_ringhalf_2.fits|link=LFI_SkyMap_030_1024_R1.10_nominal_ringhalf_2.fits}}<br />
|-<br />
| '''44GHz''' || {{PLASingleFile|fileType=map|name=LFI_SkyMap_044_1024_R1.10_nominal_ringhalf_1.fits|link=LFI_SkyMap_044_1024_R1.10_nominal_ringhalf_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=LFI_SkyMap_044_1024_R1.10_nominal_ringhalf_2.fits|link=LFI_SkyMap_044_1024_R1.10_nominal_ringhalf_2.fits}}<br />
|-<br />
| '''70GHz''' || {{PLASingleFile|fileType=map|name=LFI_SkyMap_070_1024_R1.10_nominal_ringhalf_1.fits|link=LFI_SkyMap_070_1024_R1.10_nominal_ringhalf_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=LFI_SkyMap_070_1024_R1.10_nominal_ringhalf_2.fits|link=LFI_SkyMap_070_1024_R1.10_nominal_ringhalf_2.fits}}<br />
|-<br />
| '''70GHz''' || {{PLASingleFile|fileType=map|name=LFI_SkyMap_070_2048_R1.10_nominal_ringhalf_1.fits|link=LFI_SkyMap_070_2048_R1.10_nominal_ringhalf_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=LFI_SkyMap_070_2048_R1.10_nominal_ringhalf_2.fits|link=LFI_SkyMap_070_2048_R1.10_nominal_ringhalf_2.fits}}<br />
|-<br />
| '''100GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_100_2048_R1.10_nominal_ringhalf_1.fits|link=HFI_SkyMap_100_2048_R1.10_nominal_ringhalf_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_100_2048_R1.10_nominal_ringhalf_2.fits|link=HFI_SkyMap_100_2048_R1.10_nominal_ringhalf_2.fits}}<br />
|-<br />
| '''143GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_143_2048_R1.10_nominal_ringhalf_1.fits|link=HFI_SkyMap_143_2048_R1.10_nominal_ringhalf_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_143_2048_R1.10_nominal_ringhalf_2.fits|link=HFI_SkyMap_143_2048_R1.10_nominal_ringhalf_2.fits}}<br />
|-<br />
| '''217GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_217_2048_R1.10_nominal_ringhalf_1.fits|link=HFI_SkyMap_217_2048_R1.10_nominal_ringhalf_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_217_2048_R1.10_nominal_ringhalf_2.fits|link=HFI_SkyMap_217_2048_R1.10_nominal_ringhalf_2.fits}}<br />
|-<br />
| '''353GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_353_2048_R1.10_nominal_ringhalf_1.fits|link=HFI_SkyMap_353_2048_R1.10_nominal_ringhalf_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_353_2048_R1.10_nominal_ringhalf_2.fits|link=HFI_SkyMap_353_2048_R1.10_nominal_ringhalf_2.fits}}<br />
|-<br />
| '''545GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_545_2048_R1.10_nominal_ringhalf_1.fits|link=HFI_SkyMap_545_2048_R1.10_nominal_ringhalf_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_545_2048_R1.10_nominal_ringhalf_2.fits|link=HFI_SkyMap_545_2048_R1.10_nominal_ringhalf_2.fits}}<br />
|-<br />
| '''857GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_857_2048_R1.10_nominal_ringhalf_1.fits|link=HFI_SkyMap_857_2048_R1.10_nominal_ringhalf_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_857_2048_R1.10_nominal_ringhalf_2.fits|link=HFI_SkyMap_857_2048_R1.10_nominal_ringhalf_2.fits}}<br />
|}<br />
---><br />
<br />
''' FITS file structure '''<br />
<br />
The FITS files for the sky maps contain a minimal primary header with no data, and a ''BINTABLE'' extension (EXTENSION 1, EXTNAME = ''FREQ-MAP'') containing the data. The structure is shows schematically in the figure below. The ''FREQ-MAP'' extension contains a 3- or a 10-column table that contain the signal, hit-count and variance maps, all in Healpix format. The 3-column case is for intensity only maps, the 10-column case is for polarisation. The number of rows is the number of map pixels, which is Npix = 12 <math>N_{side}</math><sup>2</sup> for Healpix maps, where <math>N_{side}</math> = 1024 or 2048 for most the maps presented in this chapter.<br />
<br />
[[File:FITS_FreqMap.png | 550px | center | thumb | '''FITS file structure''']]<br />
<br />
Note that file sizes are ~0.6 GB for I-only maps and ~1.9 GB for I,Q,U maps at <math>N_{side}</math> 2048 and ~0.14 GB for I-only maps and ~0.45 GB for I,Q,U maps at <math>N_{side}</math> 1024 .<br />
<br />
Keywords indicate the coordinate system (GALACTIC), the Healpix ordering scheme (NESTED), the units (K_cmb or MJy/sr) of each column, and of course the frequency channel (FREQ). Where polarisation Q and U maps are provided, the ''COSMO'' polarisation convention (used in HEALPIX) is adopted, and it is specified in the ''POLCCONV'' keyword (see [[Sky_temperature_maps#Polarization_convention_used_in_the_Planck_project|this section]]. The COMMENT fields give a one-line summary of the product, and some other information useful for traceability within the DPCs. The original filename is also given in the ''FILENAME'' keyword. The ''BAD_DATA'' keyword gives the value used by Healpix to indicate pixels for which no signal is present (these will also have a hit-count value of 0). The main parameters are summarised below:<br />
<br />
<br />
{| border="1" cellpadding="3" cellspacing="0" align="center" style="text-align:left" width=800px<br />
|+ '''Sky map file data structure'''<br />
|- bgcolor="ffdead" <br />
!colspan="4" | 1. EXTNAME = 'FREQ-MAP' : Data columns<br />
|- bgcolor="ffdead" <br />
! Column Name || Data Type || Units || Description<br />
|-<br />
|I_STOKES || Real*4 || K_cmb or MJy/sr || The Stokes I map<br />
|-<br />
|Q_STOKES || Real*4 || K_cmb or MJy/sr || The Stokes Q map (optional)<br />
|-<br />
|U_STOKES || Real*4 || K_cmb or MJy/sr || The Stokes U map (optional)<br />
|-<br />
|HITS || Int*4 || none || The hit-count map<br />
|-<br />
|II_COV || Real*4 || K_cmb<sup>2</sup> or (MJy/sr)<sup>2</sup> || The II variance map<br />
|-<br />
|IQ_COV || Real*4 || K_cmb<sup>2</sup> or (MJy/sr)<sup>2</sup> || The IQ variance map (optional)<br />
|-<br />
|IU_COV || Real*4 || K_cmb<sup>2</sup> or (MJy/sr)<sup>2</sup> || The IQ variance map (optional)<br />
|-<br />
|QQ_COV || Real*4 || K_cmb<sup>2</sup> or (MJy/sr)<sup>2</sup> || The QQ variance map (optional)<br />
|-<br />
|QU_COV || Real*4 || K_cmb<sup>2</sup> or (MJy/sr)<sup>2</sup> || The QU variance map (optional)<br />
|-<br />
|UU_COV || Real*4 || K_cmb<sup>2</sup> or (MJy/sr)<sup>2</sup> || The UU variance map (optional)<br />
|-<br />
|- bgcolor="ffdead" <br />
! Keyword || Data Type || Value || Description<br />
|-<br />
|PIXTYPE || string || HEALPIX ||<br />
|-<br />
|COORDSYS || string || GALACTIC ||Coordinate system <br />
|-<br />
|ORDERING || string || NESTED || Healpix ordering<br />
|-<br />
|POLCCONV || String || COSMO || Polarization convention<br />
|-<br />
|NSIDE || Int || 1024 or 2048 || Healpix <math>N_{side}</math> <br />
|-<br />
|FIRSTPIX || Int*4 || 0 || First pixel number<br />
|-<br />
|LASTPIX || Int*4 || 12 <math>N_{side}</math><sup>2</sup> – 1 || Last pixel number<br />
|-<br />
|FREQ || string || nnn || The frequency channel <br />
|}<br />
<br />
<br />
The same structure applies to all ''SkyMap'' products, independent of whether they are full channel, survey of half-ring. The distinction between the types of maps is present in the FITS filename (and in the traceability comment fields).<br />
<br />
'''Polarization convention used in the Planck project'''<br />
<br />
The Planck collaboration used the COSMO convention for the polarization angle (as usually used in space based CMB missions), whereas other astronomical fields usually use the IAU convention. In the following document we report the difference between these two conventions, and the consequence if it is NOT taken into account correctly in the analysis.<br />
<br />
[[File:conventions.png|thumb|center|400px|'''Figure 1. COSMO convention (left) and IAU convention (right). The versor <math>\hat{z}</math> points outwards the pointing direction in COSMO, and inwards in IAU. The bottom panel refers to the plane tangent to the sphere.''']]<br />
<br />
Changing the orientation convention is equivalent to a transformation <math>\psi'=\pi-\psi</math> of the polarization angle (Figure 1). The consequence of this transformation is the inversion of the Stokes parameter <math>U</math>.<br />
The components of the polarization tensor in the helicity basis <math>\epsilon^{\pm}=1/\sqrt{2}(\hat{x}\pm i\hat{y})</math> are:<br />
<br />
<math><br />
(Q+iU)(\hat{n}) = \sum _{\ell m}a_{2,lm}{}_{2}Y_{\ell }^{m}(\hat{n})<br />
\\(Q-iU)(\hat{n}) = \sum _{\ell m}a_{-2,lm}{}_{2}Y_{\ell }^{m}(\hat{n})<br />
</math><br />
<br />
where <math>{}_{2}Y_{\ell }^{m}(\hat{n})</math> are the spin weighted spherical harmonic functions.<br />
The <math>E</math> and <math>B</math> modes can be defined as:<br />
<math><br />
E(\hat{n}) = \sum_{\ell m}a_{E,\ell m}Y_{\ell }^{m}(\hat{n})<br />
\\B(\hat{n}) = \sum_{\ell m}a_{B,\ell m}Y_{\ell }^{m}(\hat{n})<br />
</math><br />
<br />
where the coefficients <math>a_{E,\ell m}</math> and <math>a_{B,\ell m}</math> are derived from linear combinations of the <math>a_{2,\ell m}</math> , <math>a_{-2,\ell m}</math> defined implicitly in the first equation (<math>Q\pm iU</math>).<br />
<br />
[[File:test_gradient.jpg|thumb|center|400px|]]<br />
[[File:test_curl.jpg|thumb|center|400px|'''Figure 2. Error on Planck-LFI 70 GHz <math>EE</math> (top) and <math>BB</math> (bottom) spectra, in case of wrong choice of the coordinate system convention (IAU instead of COSMO).''']]<br />
<br />
The effect of the sign inversion of <math>U</math> on the polarization spectra is a non trivial mixing of <math>E</math> and <math>B</math> modes. <br />
<br />
An example of the typical error on <math>EE</math> and <math>BB</math> auto-spectra in case of a wrong choice of the polarization basis is shown in Figure 2.<br />
<br />
BE CAREFUL about the polarization convention you are using. If the IAU convention is used in computing the power spectra, the sign of the <math>U</math> component of the Planck maps must be inverted before computing <math>E</math> and <math>B</math> modes.<br />
<br />
''' Note on the convention used by the Planck Catalogue of Compact Sources (PCCS) '''<br />
For continuity with other compact sources catolgues, the Catalogue of Compact Sources provided by Planck follows the IAU convention, and the polarization angles are defined on an interval of [-90&deg;,90&deg;]. To switch to the COSMO convention, the polarization angles listed in the catalogue have to be shifted by 90&deg; and multiplied by -1.<br />
<br />
== References ==<br />
<References /><br />
<br />
</div><br />
</div><br />
<br />
<div class="toccolours mw-collapsible mw-collapsed" style="background-color: #EEE8AA;width:80%" ><br />
'''2013 Sky temperature maps'''<br />
<br />
<div class="mw-collapsible-content"><br />
<br />
'''General description'''<br />
<br />
<br />
Sky maps give the best estimate of the intensity of the signal from the sky after removal, as far as possible, of known systematic effects and of the dipole signals induced by the motion of the solar system in the CMB and of the Planck satellite in the solar system. Sky maps are provided for the nominal Planck mission and also, separately, for the first two single surveys, the third one being covered only for a small part during the nominal mission.The details of the start and end times of each are given in [[HFIpreprocessingstatics | this table]]. As a secondary product, maps with estimates of the Zodiacal light and Far-Side-Lobes contribution removed are also provided. <br />
<br />
For characterization purposes, are also provided maps covering the nominal survey but each one using only half of the available data. These are the ''ringhalf_{1|2}'' maps, which are built using the first and second half of the stable pointing part in each pointing period. These maps are used extensively to investigate the (high frequency) noise properties the maps themselves and of other products described elsewhere (see e.g., the [[HFI-Validation | data validation]] section).<br />
<br />
To help in further processing, there are also masks of the Galactic Plane and of point sources, each provided for several different depths.<br />
<br />
All sky maps are in Healpix format, with Nside of 2048 for HFI and of 1024 for LFI (note that the LFI 70 GHz has been delivered also at Nside of 2048 to be directly comparable with HFI maps), in Galactic coordinates, and Nested ordering. The signal is given in units of K<sub>cmb</sub> for 30-353 GHz, and of MJy/sr (for a constant $\nu F_\nu$ energy distribution ) for 545 and 857 GHz. Each sky map is packaged into a ''BINTABLE'' extension of a FITS file together with a hit-count map (or hit map, for short, giving the number of observation samples that are cumulated in a pixel, all detectors combined) and a variance map (determined from the half-ring maps), and additional information is given in the FITS file header. The structure of the FITS file is given in the [[#Format | FITS file structure]] section below.<br />
<br />
<br />
'''Types of maps '''<br />
<br />
; Full channel maps<br />
: Full channel maps are built using all the valid detectors of a frequency channel and cover the nominal mission. For HFI, the 143-8 and 545-3 bolometers are rejected entirely as they are seriously affected by RTS noise. The maps are displayed in the figures below. The range is the same from 30 - 143 GHz in order to show the CMB at the same level. At higher frequencies the range is increased in order to keep the Galactic Plane from invading the whole sky.<br />
<br />
<center><br />
<gallery style="padding:0 0 0 0;" perrow=3 widths=260px heights=160px> <br />
File: SkyMap30.png| '''Nominal mission, 30 GHz'''<br />
File: SkyMap44.png | '''Nominal mission, 44 GHz'''<br />
File: SkyMap70.png | '''Nominal mission, 70 GHz'''<br />
File: SkyMap100.png | '''Nominal mission, 100 GHz'''<br />
File: SkyMap143.png | '''Nominal mission, 143 GHz'''<br />
File: SkyMap217.png | '''Nominal mission, 217 GHz'''<br />
File: SkyMap353.png | '''Nominal mission, 353 GHz'''<br />
File: SkyMap545.png | '''Nominal mission, 545 GHz'''<br />
File: SkyMap857.png | '''Nominal mission, 857 GHz'''<br />
</gallery><br />
</center><br />
<br />
; Single survey maps <br />
: Single survey maps are built using all valid detectors of a frequency channel; they cover separately the different sky surveys. The surveys are defined as the times over which the satellite spin axis rotates but 180 degrees, which, due to the position of the detectors in the focal plane does not cover the full sky, but a fraction between ~80 and 90% depending on detector position.<br />
<br />
; Detector set or detector pairs maps<br />
: These are maps built from a subset of the detectors in a frequency channel, typically our of two PSB pairs (i.e., four poloarisation-sensitive bolometers with different orientation on the sky), for HFI in order to extract a single temperature map. While none of these maps are part of the first Planck data release, the concept of ''detset'' is used, and thus it is worth mentioning it here. In particular, information by detector set is available at the [[Frequency_maps_angular_power_spectra | sky power spectrum]] level and in the [[The RIMO | RIMO]].<br />
<br />
; Half-ring maps<br />
: Half-ring maps are built using only the first or the second half of the stable pointing period data. There are thus two half-ring maps per frequency channel named ''ringhalf_1'' and ''ringhalf_2'' respectively. These maps are built for characterization purposes in order to perform null tests. In particular, the difference between the two half-ring maps at a given frequency give a good estimate of the high frequency noise in the data (albeit biased low by ~0.5% for the HFI channels due to specifics of the TOI processing).<br />
<br />
; Masks<br />
: Masks are provided of the Galactic Plane and of the point sources. For the Galactic Plane, eight masks are given covering different fractions of the sky, and for the points sources two masks are given, at the 5 and 10 sigma level, for each Planck HFI frequency channel. These are generic masks, specific masks applicable to other products are delivered with the products themselves.<br />
<br />
''' Caveats and known issues'''<br />
<br />
The primary limitation of the HFI maps are<br />
* the absence of correction of the ADC non-linearities,<br />
* the far-side lobe contribution is not accounted for in the processing and in the calibration,<br />
* the dipole removal is based on the non-relativistic approximation which leaves a weak quadrupole component in the map.<br />
And thus the overall calibration accuracy is at the 0.2% level in 100-217 GHz channels<br />
<br />
The LFI 70 GHz maps at Nside=2048 should be considered as additional product, the default are the LFI maps at Nside=1024. No effective beam at Nside=2048 is provided, only at Nside=1024, for this reason the use of the effective beam with maps at Nside 2048 is discouraged.<br />
<br />
''' Map zero-level '''<br />
<br />
For the 100 to 857 GHz maps, the zero levels are set to their optimal levels for Galactic and CIB studies. A procedure for adjusting them to astrophysical values is given in the HFI Calibration paper {{PlanckPapers|planck2013-p03b}}.<br />
<br />
For the 30, 44 and 70 GHz, maps are corrected for zero level monopole by applying an offset correction, see LFI Calibration paper {{PlanckPapers|planck2013-p02b}} section 3.4 "Setting the zero levels in the maps". Note that the offset applied is indicated in the header as a comment keyword.<br />
<br />
''' The Zodiacal light and the Far-Side Lobes '''<br />
<br />
The figures below show the modeled Zodiacal light and Far Side Lobes projected onto the maps; they are simply the difference between the ''main product'' and the ''ZodiCorrected'' maps for the nominal mission. The units are given in the figures. The ''heat'' color table has been used in place of the standard Planck for clarity reasons. <br />
<center><br />
<gallery perrow=3 widths=260px heights=170px><br />
File: ZodiRes100.png | '''zodi/FSL rediduals - 100 GHz'''<br />
File: ZodiRes143.png | '''zodi/FSL rediduals - 143 GHz''' <br />
File: ZodiRes217.png | '''zodi/FSL rediduals - 217 GHz'''<br />
File: ZodiRes353.png | '''zodi/FSL rediduals - 353 GHz'''<br />
File: ZodiRes545.png | '''zodi/FSL rediduals - 545 GHz'''<br />
File: ZodiRes857.png | '''zodi/FSL rediduals - 857 GHz'''<br />
</gallery><br />
</center><br />
The effects of the FSLs are seen most clearly at the highest frequencies, as structures roughly symmetric about the center of the image, which corresponds to the location of the Galactic Centre, which is in turn the source of most of the radiation that is scattered into the FSLs.<br />
<br />
''' Artifacts near caustics of the scanning strategy '''<br />
<br />
The [[Survey scanning and performance|scanning strategy]] is such that regions around the Ecliptic poles are surveyed very deeply and compared to the average, and the transition from the nominal depth to the high depth, as shows on hit-count maps is very rapid, namely a few pixels, for a contrast of ~30. These transitions, or caustics in the maps, occur at different positions on the sky for different detectors, as the positions depend on their location in the focal plane of the instrument. As a result, when data from different detectors are combined to build a full channel map, the the weights of different detectors in the mix changes rapidly across the caustic, and given the remaining errors in the relative calibration of the detectors, a visible effect can be introduced in the maps, especially when the SNR is very high, i.e. at the highest frequencies and near bright regions like the Galactic Plane. Some examples are shown below.<br />
<br />
<center><br />
<gallery perrow=3 heights=260px widths=260pix ><br />
File: causta857.png | '''857 GHz intensity map around (272.5, -27)'''<br />
File: caustb857.png | '''857 GHz intensity map around (264.5, -37.5)'''<br />
File: caustc857.png | '''857 GHz intensity map around (98.5, 43)'''<br />
File: hita857.png | '''857 GHz hit count map around (272.5, -27)'''<br />
File: hitb857.png | '''857 GHz hit count map around (264.5, -37.5)'''<br />
File: hitc857.png | '''857 GHz hit count map around (98.5, 43)'''<br />
</gallery><br />
</center><br />
<br />
'''Production process'''<br />
<br />
<br />
Sky maps are produced by combining appropriately the data of all working detectors in a frequency channel over some period of the mission. They give the best estimate of the signal from the sky (unpolarised) after removal, as far as possible, of known systematic effects and of the dipole signals induced by the motion of the solar system in the CMB and of the Planck satellite in the solar system. In particular, they include the Zodiacal light emission (Zodi for short) and also the scattering from the far-side lobes of the beams (FSL). More on this below.<br />
<br />
''' HFI processing '''<br />
<br />
The inputs to the mapmaking are TOIs of signal that have been cleaned (as far as possible) of instrumental effects and calibrated in absorbed watts. While the processing involved is described in detail in the [[TOI processing|TOI processing]] section, we give a very brief summary here for convenience. That pipeline performs the following operations:<br />
<br />
; demodulation: this is performed around a variable level which is determined from the valid input data (a validity flag from a previous version of the processing is used for this purpose), and the data are converted to engineering units (V) using known conversion coefficients.<br />
; despiking: using the demodulated data converted to V (by the transfer function) the glitches are identified and fitted with templates. A glitch flag is produced that identifies the strongest part of the glitches, and a timeline of glitch tails is produced from the template fits, and subtracted from the demodulated timeline from step 1. Finally, the flagged ranges are replaced with data from an average over the pointing period (TBC)<br />
; dark template removal: the two dark bolometers are demodulated and despiked as above; the resulting timelines are then smoothed and used as an indicator of the overall temperature variations of the bolometer plate. Where the variations are consistent with each other, they are combined and removed from the bolometer signal timelines using appropriate coupling coefficients. The few percent of the data where they are not consistent are flagged on the timelines.<br />
; conversion to absorbed power: the timeline is converted to watts of absorbed power using the bolometer function. This includes a non-linearity correction; removal of the 4K cooler lines: the electromagnetic interference of the 4K cooler with the bolometer readout wires induces some sharp lines in the signal power spectra at frequencies of the 4K cooler's fundamental and its multiples, folded by the signal modulations. Fourier coefficients of the relevant lines are determined on a per-ring basis, and then removed from the data. The quality of the removal depends on the bolometer.<br />
; deconvolution by the time transfer function: this is done to correct for the non-instantaneous time response of the bolometers. The function itself is modeled using 4 parameters which are adjusted primarily on the planet data and also from comparisons of the northward and southward scans of the Galactic Plane. It is then removed using Fourier techniques, which has the side-effect of increasing the noise at high frequencies.<br />
; jump correction: removes some (relatively rare: 0.3 jumps per bolometer per pointing period, on average) jumps in the signal baseline. The jumps are detected characterized on smoothed TOIs, and corrected by adding a constant to part of the signal timeline. The origin of the jumps is not known.<br />
<br />
The results of this processing are a timeline of signal (in absorbed watts) and a ''valid data'' flag timeline for each of the 50 valid bolometers processed; these timelines contain the full sky signal, i.e., including the solar and orbital dipoles, the Zodiacal light, and contributions from the Far-Side lobes. The dipoles are necessary for the flux calibration and are removed at the mapmaking stage. The remaining two bolometers (143-8 and 535-3) show semi-random jumps in the signal level, typically jumping over 2-5 different ''pseudo-baseline'' levels, a behavior known as ''Random Telegraphic Signal'', so that these are commonly called the RTS bolometers. Finally, ring-level statistics of different types (mean, median, rms, kurtosis, etc.) are determined on a per-ring basis for all timelines, and a selection based on these statistics is used to discard anomalous rings, which are recorded in a ring-level flag for each valid bolometer timeline (see the [[TOI_processing#Discarded_rings| Discarded rings]] section). <br />
<br />
Throughout this processing, bright planets (Mars, Jupiter, Saturn, Uranus) and bright asteroids are masked in the timeline in order to avoid ringing effects in the processing. Since they move on the sky, the portion of the sky masked during one survey is observed during one, and no hole is left in the final map. In parallel, the planet data are processed in a similar way, but with different parameters for the despiking step, and without the final jump correction step. These results are processed separately to determine the beam shapes and the focal plane geometry.<br />
<br />
The pointing is determined starting from the AHF produced by MOC, which gives the direction and orientation of the LOS of a fiducial position in the focal plane at frequencies of 8Hz during stable pointing and 4 Hz during maneuvers (TBC for details, reference). This is interpolated to the times of data observation (ref to method), corrected for the wobble and other time-dependent offsets determined from the observed positions of a large number of sources around the sky, and finally converted to the LOS of each detector using the quaternions in the IMO (which are determined from observations of bright planets - see the [[Detector_pointing]] section). <br />
<br />
The mapmaking and calibration process is described in detail in the [[Map-making_LFI | Map-making]] section, where detailed references are found. In brief it consists of:<br />
<br />
; binning the TOI data onto ''rings'' : Healpix rings (HPRs) are used here, each ring containing the combined data of one pointing period. <br />
; flux calibration : at 100-353 GHz, the flux calibration factors are determined for each pointing period (or ring) from the solar-motion dipole, using the WMAP dipole as the reference, and after removal of the dipole signal induced by the motion of the Planck satellite in the solar system. This gain by ring is smoothed with a window of width 50 rings, which reveals an apparent variation of ~1-2% on a scale of 100s to 1000s of rings for the 100-217 GHz channels, and is applied. At 353GHz, where the solar motion dipole is weaker compared to the signal, no gain variation is detected (within the uncertainties), and a single fixed gain is applied to all rings. At 545 and 857 GHz the gain is determined from the observation of Uranus and Neptune (but not Jupiter which is too bright) and comparison to recent models made explicitly for this mission. A single gain is applied to all rings at these frequencies.<br />
; destriping : in order to remove low-frequency noise, an offset per ring is determined by minimizing the differences between HPRs at their crossings, and removed.<br />
; projection onto the map : the offset-corrected and flux-calibrated HPRs are projected onto Healpix maps, with the data of each bolometer weighted by a factor of 1/NET of that bolometer, and accounting for the slight different band transmission profiles of the bolometers in each band. <br />
<br />
These maps provide the main mission products. A second, reduced, set of maps, cleaned of the Zodiacal emission of the FSL leakage is also produced for the nominal mission and the two single surveys, but not for the half-rings (since the contribution would be the same for the two halves of each ring). For this purpose, the the Zodiacal emission and the FSL contamination, which are not fixed on the sky, are modeled separately at HPR-level, and subtracted from the signal HPR before projecting them onto the maps. <br />
<br />
Together with signal maps, hit count and variance maps are also produced. The hit maps give the (integer) number of valid TOI-level samples that contribute to the signal of each pixel. All valid samples are counted in the same way, i.e., there is no weighting factor applied. The variance maps project the white noise estimate, provided by the NETs, in the sky domain.<br />
<br />
''' LFI processing '''<br />
<br />
LFI maps were constructed with the Madam map-making code, version 3.7.4. The code is based on generalized destriping technique, where the correlated noise component is modeled as a sequence of constant offset, called baselines. A noise filter was used to constrain the baseline solution allowing the use of 1 second baselines.<br />
<br />
Radiometers were combined according to the horn-uniform weighting scheme to minimize systematics. The used weights are listed in [[Map-making LFI#Map-making|Map-making]]. The flagged samples were excluded from the analysis by setting their weights to $C_{w}^{-1}$ = 0. The galaxy region was masked out in the destriping phase, to reduce error arising from strong signal gradients. The polarization component was included in the analysis, although only the temperature maps are released. <br />
<br />
A detailed description of the map-making procedure is given in {{PlanckPapers|planck2013-p02}} and in section [[Map-making LFI#Map-making|Map-making]].<br />
<br />
'''Inputs'''<br />
<br />
<br />
''' HFI inputs '''<br />
<br />
* The cleaned TOIs of signal of each detector, together with their flags, produced by the [[TOI processing|TOI processing]] pipeline<br />
* The TOIs of pointing (quaternions), described in [[Detector_pointing]]<br />
* Bolometer-level characterization data, from the DPC's internal IMO (not distributed)<br />
* Planck orbit data used to compute and remove the earth dipole<br />
* WMAP solar dipole information used to calibrate the CMB channels<br />
* Planet models used to calibrate the Galactic channels.<br />
<br />
''' LFI inputs '''<br />
<br />
The Madam map-maker takes as an input:<br />
<br />
* The calibrated timelines (for details see [[TOI processing LFI|TOI Processing]])<br />
* The detector pointings (for details see [[Detector pointing|Detector pointing]])<br />
* The noise information in the form of three-parameter (white noise level ($\sigma$), slope, and knee frequency ($f_\mathrm{knee}$)) noise model (for details see [[The RIMO|RIMO]])<br />
<br />
'''Related products'''<br />
<br />
<br />
''' Masks '''<br />
<br />
Masks are provided of<br />
<br />
; the point sources<br />
: 15 masks are provided, three for the LFI (one mask for each frequency masking at the 4<math>\sigma</math> level) and 12 for the HFI (two masks for each frequency at the 5 and 10<math>\sigma</math> levels. For the HFI the masks can be used as they are, for the LFI they need to be downgraded to Nside=1024 except for the 70 GHz channel at Nside=2048 which does not need to be downgraded.<br />
<br />
; the Galactic Plane<br />
: 8 masks are provided giving 20, 40, 60, 70, 80, 90, 97, and 99% sky coverage in two different files, at Nside=2048. For the HFI they can be used as they are, for the LFI they need to be downgraded at Nside=1024 (note that if using the 70 GHZ at Nside=2048 no downgraded is needed)<br />
<br />
<br />
The masks are binary, in GALACTIC coordinates, and NESTED ordering. The table below give the filenames. <br />
<br />
<br />
{| class="wikitable" align="center" style="text-align:center" border="1" cellpadding="5" cellspacing="0" <br />
|+ '''FITS filenames for masks'''<br />
|-bgcolor="ffdead"<br />
! Frequency || LFI Point Source masks<br />
|-<br />
| '''30GHz''' || {{PLASingleFile|fileType=map|name=LFI_MASK_030-ps_2048_R1.00.fits|link=LFI_MASK_030-ps_2048_R1.00.fits}}<br />
|-<br />
| '''44GHz''' || {{PLASingleFile|fileType=map|name=LFI_MASK_044-ps_2048_R1.00.fits|link=LFI_MASK_044-ps_2048_R1.00.fits}}<br />
|-<br />
| '''70GHz''' || {{PLASingleFile|fileType=map|name=LFI_MASK_070-ps_2048_R1.00.fits|link=LFI_MASK_070-ps_2048_R1.00.fits}}<br />
|- bgcolor="ffdead"<br />
! colspan="2" | HFI Point Source masks<br />
|-<br />
| colspan="2" | {{PLASingleFile|fileType=map|name=HFI_Mask_PointSrc_2048_R1.10.fits|link=HFI_Mask_PointSrc_2048_R1.10.fits}}<br />
|- bgcolor="ffdead"<br />
! colspan="2" | Galactic Plane masks<br />
|-<br />
| colspan="2" | {{PLASingleFile|fileType=map|name=HFI_Mask_GalPlane_2048_R1.10.fits|link=HFI_Mask_GalPlane_2048_R1.10.fits}} <br />
|}<br />
<br />
<br />
The masks are shows below in a single figure. While this is quite clear for the Galactic Plane masks, it is less so for the point source masks, but it does give a clear perspective on how the latter are distributed over the sky.<br />
<br />
<center><br />
<gallery perrow=2 widths=300px heights=185px ><br />
File: HFI_GalPlaneMask.png | '''Galactic Plane masks'''<br />
File: HFI_PointSrcMask.png | '''PointSource masks'''<br />
</gallery><br />
</center><br />
<br />
''' File names '''<br />
<br />
<br />
The FITS filenames are of the form ''{H|L}FI_SkyMap_fff_nnnn_R1.nn_{coverage}_{type}.fits'', where ''fff'' are three digits to indicate the Planck frequency band, and ''nnnn'' is the Healpix Nside of the map, ''coverage'' indicates which part of the mission is covered, and the optional ''type'' indicates the subset of input data used. A full list of products, with links to them in the Archive, is given in the tables below.<br />
<br />
For the benefit of users who are only looking for the frequency maps with no additional information, we also provide a file combining the 9 frequency maps as separate columns in a single extension. The 9 columns in this file contain the intensity maps ONLY and no other information (hit maps and variance maps) is provided.<br />
<br />
{| class="wikitable" align="center" style="text-align:center" border="1" cellpadding="5" cellspacing="0" width=500px<br />
|+ '''FITS filenames'''<br />
|- bgcolor="ffdead"<br />
! Frequency || Full channel maps<br />
|-<br />
| '''30GHz''' || {{PLASingleFile|fileType=map|name=LFI_SkyMap_030_1024_R1.10_nominal.fits|link=LFI_SkyMap_030_1024_R1.10_nominal.fits}}<br />
|-<br />
| '''44GHz''' || {{PLASingleFile|fileType=map|name=LFI_SkyMap_044_1024_R1.10_nominal.fits|link=LFI_SkyMap_044_1024_R1.10_nominal.fits}}<br />
|-<br />
| '''70GHz''' || {{PLASingleFile|fileType=map|name=LFI_SkyMap_070_1024_R1.10_nominal.fits|link=LFI_SkyMap_070_1024_R1.10_nominal.fits}}<br />
|-<br />
| '''70GHz''' || {{PLASingleFile|fileType=map|name=LFI_SkyMap_070_2048_R1.10_nominal.fits|link=LFI_SkyMap_070_2048_R1.10_nominal.fits}}<br />
|-<br />
| '''100GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_100_2048_R1.10_nominal.fits|link=HFI_SkyMap_100_2048_R1.10_nominal.fits}}<br />
|-<br />
| '''143GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_143_2048_R1.10_nominal.fits|link=HFI_SkyMap_143_2048_R1.10_nominal.fits}}<br />
|-<br />
| '''217GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_217_2048_R1.10_nominal.fits|link=HFI_SkyMap_217_2048_R1.10_nominal.fits}}<br />
|-<br />
| '''353GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_353_2048_R1.10_nominal.fits|link=HFI_SkyMap_353_2048_R1.10_nominal.fits}}<br />
|-<br />
| '''545GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_545_2048_R1.10_nominal.fits|link=HFI_SkyMap_545_2048_R1.10_nominal.fits}}<br />
|-<br />
| '''857GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_857_2048_R1.10_nominal.fits|link=HFI_SkyMap_857_2048_R1.10_nominal.fits}}<br />
|- bgcolor="ffdead"<br />
! Frequency || Full channel, Zodi-corrected maps<br />
|-<br />
| '''100GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_100_2048_R1.10_nominal_ZodiCorrected.fits|link=HFI_SkyMap_100_2048_R1.10_nominal_ZodiCorrected.fits}} <br />
|-<br />
| '''143GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_143_2048_R1.10_nominal_ZodiCorrected.fits|link=HFI_SkyMap_143_2048_R1.10_nominal_ZodiCorrected.fits}}<br />
|-<br />
| '''217GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_217_2048_R1.10_nominal_ZodiCorrected.fits|link=HFI_SkyMap_217_2048_R1.10_nominal_ZodiCorrected.fits}}<br />
|-<br />
| '''353GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_353_2048_R1.10_nominal_ZodiCorrected.fits|link=HFI_SkyMap_353_2048_R1.10_nominal_ZodiCorrected.fits}}<br />
|-<br />
| '''545GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_545_2048_R1.10_nominal_ZodiCorrected.fits|link=HFI_SkyMap_545_2048_R1.10_nominal_ZodiCorrected.fits}}<br />
|-<br />
| '''857GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_857_2048_R1.10_nominal_ZodiCorrected.fits|link=HFI_SkyMap_857_2048_R1.10_nominal_ZodiCorrected.fits}}<br />
|- bgcolor="ffdead"<br />
! Frequency || Combined frequency maps<br />
|-<br />
| '''All''' || {{PLASingleFile|fileType=file|name=COM_MapSet_I-allFreqs_R1.10_nominal.fits|link=COM_MapSet_I-allFreqs_R1.10_nominal.fits}} <br />
|}<br />
<br />
<br />
{| class="wikitable" align="center" style="text-align:center" border="1" cellpadding="5" cellspacing="0" width=850px<br />
|+ '''FITS filenames'''<br />
|- bgcolor="ffdead"<br />
! Frequency || Survey 1 maps || Survey 2 maps<br />
|-<br />
| '''30GHz''' || {{PLASingleFile|fileType=map|name=LFI_SkyMap_030_1024_R1.10_survey_1.fits|link=LFI_SkyMap_030_1024_R1.10_survey_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=LFI_SkyMap_030_1024_R1.10_survey_2.fits|link=LFI_SkyMap_030_1024_R1.10_survey_2.fits}}<br />
|-<br />
| '''44GHz''' || {{PLASingleFile|fileType=map|name=LFI_SkyMap_044_1024_R1.10_survey_1.fits|link=LFI_SkyMap_044_1024_R1.10_survey_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=LFI_SkyMap_044_1024_R1.10_survey_2.fits|link=LFI_SkyMap_044_1024_R1.10_survey_2.fits}}<br />
|-<br />
| '''70GHz''' || {{PLASingleFile|fileType=map|name=LFI_SkyMap_070_1024_R1.10_survey_1.fits|link=LFI_SkyMap_070_1024_R1.10_survey_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=LFI_SkyMap_070_1024_R1.10_survey_2.fits|link=LFI_SkyMap_070_1024_R1.10_survey_2.fits}}<br />
|-<br />
| '''70GHz''' || {{PLASingleFile|fileType=map|name=LFI_SkyMap_070_2048_R1.10_survey_1.fits|link=LFI_SkyMap_070_2048_R1.10_survey_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=LFI_SkyMap_070_2048_R1.10_survey_2.fits|link=LFI_SkyMap_070_2048_R1.10_survey_2.fits}}<br />
|-<br />
| '''100GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_100_2048_R1.10_survey_1.fits|link=HFI_SkyMap_100_2048_R1.10_survey_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_100_2048_R1.10_survey_2.fits|link=HFI_SkyMap_100_2048_R1.10_survey_2.fits}}<br />
|-<br />
| '''143GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_143_2048_R1.10_survey_1.fits|link=HFI_SkyMap_143_2048_R1.10_survey_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_143_2048_R1.10_survey_2.fits|link=HFI_SkyMap_143_2048_R1.10_survey_2.fits}}<br />
|-<br />
| '''217GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_217_2048_R1.10_survey_1.fits|link=HFI_SkyMap_217_2048_R1.10_survey_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_217_2048_R1.10_survey_2.fits|link=HFI_SkyMap_217_2048_R1.10_survey_2.fits}}<br />
|-<br />
| '''353GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_353_2048_R1.10_survey_1.fits|link=HFI_SkyMap_353_2048_R1.10_survey_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_353_2048_R1.10_survey_2.fits|link=HFI_SkyMap_353_2048_R1.10_survey_2.fits}}<br />
|-<br />
| '''545GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_545_2048_R1.10_survey_1.fits|link=HFI_SkyMap_545_2048_R1.10_survey_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_545_2048_R1.10_survey_2.fits|link=HFI_SkyMap_545_2048_R1.10_survey_2.fits}}<br />
|-<br />
| '''857GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_857_2048_R1.10_survey_1.fits|link=HFI_SkyMap_857_2048_R1.10_survey_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_857_2048_R1.10_survey_2.fits|link=HFI_SkyMap_857_2048_R1.10_survey_2.fits}}<br />
|- bgcolor="ffdead"<br />
! Frequency || Survey 1 Zodi-corrected maps || Survey 2 Zodi-corrected maps<br />
|-<br />
| '''100GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_100_2048_R1.10_survey_1_ZodiCorrected.fits|link=HFI_SkyMap_100_2048_R1.10_survey_1_ZodiCorrected.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_100_2048_R1.10_survey_2_ZodiCorrected.fits|link=HFI_SkyMap_100_2048_R1.10_survey_2_ZodiCorrected.fits}}<br />
|-<br />
| '''143GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_143_2048_R1.10_survey_1_ZodiCorrected.fits|link=HFI_SkyMap_143_2048_R1.10_survey_1_ZodiCorrected.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_143_2048_R1.10_survey_2_ZodiCorrected.fits|link=HFI_SkyMap_143_2048_R1.10_survey_2_ZodiCorrected.fits}}<br />
|-<br />
| '''217GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_217_2048_R1.10_survey_1_ZodiCorrected.fits|link=HFI_SkyMap_217_2048_R1.10_survey_1_ZodiCorrected.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_217_2048_R1.10_survey_2_ZodiCorrected.fits|link=HFI_SkyMap_217_2048_R1.10_survey_2_ZodiCorrected.fits}}<br />
|-<br />
| '''353GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_353_2048_R1.10_survey_1_ZodiCorrected.fits|link=HFI_SkyMap_353_2048_R1.10_survey_1_ZodiCorrected.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_353_2048_R1.10_survey_2_ZodiCorrected.fits|link=HFI_SkyMap_353_2048_R1.10_survey_2_ZodiCorrected.fits}}<br />
|-<br />
| '''545GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_545_2048_R1.10_survey_1_ZodiCorrected.fits|link=HFI_SkyMap_545_2048_R1.10_survey_1_ZodiCorrected.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_545_2048_R1.10_survey_2_ZodiCorrected.fits|link=HFI_SkyMap_545_2048_R1.10_survey_2_ZodiCorrected.fits}}<br />
|-<br />
| '''857GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_857_2048_R1.10_survey_1_ZodiCorrected.fits|link=HFI_SkyMap_857_2048_R1.10_survey_1_ZodiCorrected.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_857_2048_R1.10_survey_2_ZodiCorrected.fits|link=HFI_SkyMap_857_2048_R1.10_survey_2_ZodiCorrected.fits}}<br />
|- bgcolor="ffdead"<br />
! Frequency || Half-ring 1 maps ||Half-ring 2 maps<br />
|-<br />
| '''30GHz''' || {{PLASingleFile|fileType=map|name=LFI_SkyMap_030_1024_R1.10_nominal_ringhalf_1.fits|link=LFI_SkyMap_030_1024_R1.10_nominal_ringhalf_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=LFI_SkyMap_030_1024_R1.10_nominal_ringhalf_2.fits|link=LFI_SkyMap_030_1024_R1.10_nominal_ringhalf_2.fits}}<br />
|-<br />
| '''44GHz''' || {{PLASingleFile|fileType=map|name=LFI_SkyMap_044_1024_R1.10_nominal_ringhalf_1.fits|link=LFI_SkyMap_044_1024_R1.10_nominal_ringhalf_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=LFI_SkyMap_044_1024_R1.10_nominal_ringhalf_2.fits|link=LFI_SkyMap_044_1024_R1.10_nominal_ringhalf_2.fits}}<br />
|-<br />
| '''70GHz''' || {{PLASingleFile|fileType=map|name=LFI_SkyMap_070_1024_R1.10_nominal_ringhalf_1.fits|link=LFI_SkyMap_070_1024_R1.10_nominal_ringhalf_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=LFI_SkyMap_070_1024_R1.10_nominal_ringhalf_2.fits|link=LFI_SkyMap_070_1024_R1.10_nominal_ringhalf_2.fits}}<br />
|-<br />
| '''70GHz''' || {{PLASingleFile|fileType=map|name=LFI_SkyMap_070_2048_R1.10_nominal_ringhalf_1.fits|link=LFI_SkyMap_070_2048_R1.10_nominal_ringhalf_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=LFI_SkyMap_070_2048_R1.10_nominal_ringhalf_2.fits|link=LFI_SkyMap_070_2048_R1.10_nominal_ringhalf_2.fits}}<br />
|-<br />
| '''100GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_100_2048_R1.10_nominal_ringhalf_1.fits|link=HFI_SkyMap_100_2048_R1.10_nominal_ringhalf_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_100_2048_R1.10_nominal_ringhalf_2.fits|link=HFI_SkyMap_100_2048_R1.10_nominal_ringhalf_2.fits}}<br />
|-<br />
| '''143GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_143_2048_R1.10_nominal_ringhalf_1.fits|link=HFI_SkyMap_143_2048_R1.10_nominal_ringhalf_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_143_2048_R1.10_nominal_ringhalf_2.fits|link=HFI_SkyMap_143_2048_R1.10_nominal_ringhalf_2.fits}}<br />
|-<br />
| '''217GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_217_2048_R1.10_nominal_ringhalf_1.fits|link=HFI_SkyMap_217_2048_R1.10_nominal_ringhalf_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_217_2048_R1.10_nominal_ringhalf_2.fits|link=HFI_SkyMap_217_2048_R1.10_nominal_ringhalf_2.fits}}<br />
|-<br />
| '''353GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_353_2048_R1.10_nominal_ringhalf_1.fits|link=HFI_SkyMap_353_2048_R1.10_nominal_ringhalf_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_353_2048_R1.10_nominal_ringhalf_2.fits|link=HFI_SkyMap_353_2048_R1.10_nominal_ringhalf_2.fits}}<br />
|-<br />
| '''545GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_545_2048_R1.10_nominal_ringhalf_1.fits|link=HFI_SkyMap_545_2048_R1.10_nominal_ringhalf_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_545_2048_R1.10_nominal_ringhalf_2.fits|link=HFI_SkyMap_545_2048_R1.10_nominal_ringhalf_2.fits}}<br />
|-<br />
| '''857GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_857_2048_R1.10_nominal_ringhalf_1.fits|link=HFI_SkyMap_857_2048_R1.10_nominal_ringhalf_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_857_2048_R1.10_nominal_ringhalf_2.fits|link=HFI_SkyMap_857_2048_R1.10_nominal_ringhalf_2.fits}}<br />
|}<br />
<br />
''' FITS file structure '''<br />
<br />
<br />
[[File:FITS_FreqMap.png | 500px | right | thumb | '''FITS file structure''']]<br />
<br />
The FITS files for the sky maps contain a minimal primary header with no data, and a ''BINTABLE'' extension (EXTENSION 1, EXTNAME = ''FREQ-MAP'') containing the data. The structure is shows schematically in the figure at right. <br />
<br />
The ''FREQ-MAP'' extension contains is a 3-column table that contain the signal, hit-count and variance maps, all in Healpix format, in columns 1, 2, and 3, respectively. The number of rows is 50331648 for HFI and LFI 70 GHz at Nside=2048 and 12582912 for LFI maps at Nside=1024 (N.B: Npix = 12 Nside^2). The three columns are ''I_STOKES'' for the intensity (or temperature) signal, ''HIT'' for the hit-count and ''II_COV'' for the variance. The exact order of the columns in the figure is indicative only, and the details can be found in the keywords. <br />
<br />
Keywords indicate the coordinate system (GALACTIC), the Healpix ordering scheme (NESTED), the units (K_cmb or MJy/sr) of each column, and of course the frequency channel (FREQ). The COMMENT fields give a one-line summary of the product, and some other information useful for traceability within the DPCs. The original filename is also given in the ''FILENAME'' keyword as are the datasum and the md5 checksum for the extension. The ''BAD_DATA'' keyword gives the value used by Healpix to indicate pixels for which no signal is present (these will also have a hit-count value of 0). The COMMENT fields give further information including some traceability data for the DPC's. The main parameters are summarised below:<br />
<br />
<br />
{| border="1" cellpadding="3" cellspacing="0" align="center" style="text-align:left" width=800px<br />
|+ '''Sky map file data structure'''<br />
|- bgcolor="ffdead" <br />
!colspan="4" | 1. EXTNAME = 'FREQ-MAP' : Data columns<br />
|- bgcolor="ffdead" <br />
! Column Name || Data Type || Units || Description<br />
|-<br />
|I_STOKES || Real*4 || K_cmb or MJy/sr || The signal map<br />
|-<br />
|HITS || Int*4 || none || The hit-count map<br />
|-<br />
|II_COV || Real*4 || K_cmb<sup>2</sup> or (MJy/sr)<sup>2</sup> || The variance map<br />
|- bgcolor="ffdead" <br />
! Keyword || Data Type || Value || Description<br />
|-<br />
|PIXTYPE || string || HEALPIX ||<br />
|-<br />
|COORDSYS || string || GALACTIC ||Coordinate system <br />
|-<br />
|ORDERING || string || NESTED || Healpix ordering<br />
|-<br />
|NSIDE || Int || 1024 or 2048 || Healpix Nside <br />
|-<br />
|FIRSTPIX || Int*4 || 0 || First pixel number<br />
|-<br />
|LASTPIX || Int*4 || 12582911 or 50331647 || Last pixel number<br />
|-<br />
|FREQ || string || nnn || The frequency channel <br />
|}<br />
<br />
<br />
The same structure applies to all ''SkyMap'' products, independent of whether they are full channel, survey of half-ring. The distinction between the types of maps is present in the FITS filename (and in the traceability comment fields).<br />
<br />
''' References'''<br />
<br />
<References /><br />
<br />
<br />
</div><br />
</div><br />
<br />
<br />
<br />
[[Category:Mission products|002]]</div>Azaccheihttps://wiki.cosmos.esa.int/planck-legacy-archive/index.php?title=Frequency_maps&diff=14113Frequency maps2018-07-06T13:47:43Z<p>Azacchei: /* File names */</p>
<hr />
<div>{{DISPLAYTITLE:Frequency maps in Temperature and Polarization}}<br />
==General description==<br />
<br />
Sky maps give the best estimate of the intensity and polarization (Stokes <i>Q</i> and <i>U</i> components), if available, of the signal from the sky after removal, as far as possible, of known systematic effects (mostly instrumental, but including also the solar and Earth-motion dipoles, Galactic stray light, and the zodiacal light). The Planck Collaboration has made three releases of maps, in 2013, 2015 and 2018. This section describes the 2018 release. For descriptions of the other two releases, please go to 2013, and 2015.<br />
<br />
In the 2013, 2015 and 2018 releases, sky maps are provided for the full Planck mission using all valid detectors in each frequency channel, and also for various subsets obtained by splitting the mission into various time ranges or into subsets of the detectors in a given channel, or by considering only odd or even pointing periods. These products are especially interesting for characterization purposes (see also the [[HFI-Validation | data validation]] section), though some are also useful for the study of source variability. The details of the start and end of the time ranges are given in the table below. <br />
<br />
For this (2018) release, HFI is providing a more limited subset of maps that include the full channel maps, the half-mission and the odd-even ring splits. Also, note that for the 353 GHz band, both full channel and PSBs only maps are provided, and that by default it is the PBS-only maps that are served.<br />
<br />
<br />
{| border="1" cellpadding="3" cellspacing="0" align="center" style="text-align:left" width=800px<br />
|+ '''Ranges for mission and surveys'''<br />
|- bgcolor="ffdead" <br />
! Range || ODs || HFI rings || pointing-IDs || Comment<br />
|-<br />
|Nominal mission || 91 - 563 || 240 - 14723 || 00004200 - 03180200 ||<br />
|-<br />
|Full mission || 91 - 974 || 240 - 27005 || 00004200 - 05322620 || For HFI<br />
|-<br />
|Full mission || 91 - 1543 || n/a || 00004200 - 06511160 || For LFI<br />
|-<br />
|Survey 1 || 91 - 270 || 240 - 5720 || 00004200 - 01059820 ||<br />
|-<br />
|Survey 2 || 270 - 456 || 5721 - 11194 || 01059830 - 02114520 ||<br />
|-<br />
|Survey 3 || 456 - 636 || 11195 - 16691 || 02114530 - 03193660 ||<br />
|-<br />
|Survey 4 || 636 - 807 || 16692 - 21720 || 03193670 - 04243900 ||<br />
|-<br />
|Survey 5 || 807 - 974 || 21721 - 26050 || 05267180 - 05322590 || End of mission for HFI<br />
|-<br />
|Survey 5 || 807 - 993 || n/a || 05267180 - 06344800 || End of survey for LFI<br />
|-<br />
|Survey 6 || 993 - 1177 || n/a || 06344810 - 06398120 || LFI only <br />
|-<br />
|Survey 7 || 1177 - 1358 || n/a || 06398130 - 06456410 || LFI only <br />
|-<br />
|Survey 8 || 1358 - 1543 || n/a || 06456420 - 06511160 || LFI only <br />
|-<br />
|HFI mission-half-1 || 91 - 531 || 240 - 13471 || 00004200 - 03155580 ||<br />
|-<br />
|HFI mission-half-2 || 531 - 974 || 13472 - 27005 || 03155590 - 05322590 ||<br />
|-<br />
|LFI Year 1 || 91 - 456 || n/a || 00004200 - 02114520 ||<br />
|-<br />
|LFI Year 2 || 456 - 807 || n/a || 02114530 - 04243900 ||<br />
|-<br />
|LFI Year 3 || 807 - 1177 || n/a || 05267180 - 06398120 ||<br />
|-<br />
|LFI Year 4 || 1177 - 1543 || n/a || 06398130 - 06511160 ||<br />
|-<br />
|}<br />
<br />
To help in further processing, there are also masks of the Galactic plane and of point sources, each provided for several different depths. <br />
<br />
All sky maps are in HEALPix format, with <i>N</i><sub>side</sub>=1024 (for LFI 30, 44, and 70GHz) and 2048 (for LFI 70GHz and HFI), in Galactic coordinates, and with nested ordering. <br />
<br />
'''WARNING''': The HEALPix convention for polarization is <b>not</b> the same as the IAU convention ([[#Polarization convention used in the Planck project|Section 8 on this page]]).<br />
<br />
The signal is given in units of K<sub>CMB</sub> for 30 to 353 GHz, and of MJy.sr<sup>-1</sup> (for a constant &nu;<i>I</i><sub>&nu;</sub> energy distribution) for 545 and 857 GHz. For each frequency channel, the intensity and polarization maps are packaged into a "BINTABLE" extension of a FITS file together with a hit-counts map (or "hits map", for short, giving the number of observation samples that are accumulated in a pixel, all detectors combined) and with the variance and covariance maps. Additional information is given in the FITS file header. The structure of the FITS file is given in the [[#FITS_file_structure | FITS file structure]] section below.<br />
<br />
==Production process==<br />
<br />
Sky maps are produced by appropriately combining the data from all working detectors in a frequency channel over some period of the mission. They give the best estimate of the signal from the sky (unpolarized) after removal, as far as possible, of known systematic effects and of the dipole signals induced by the motion of the solar system in the CMB and of the Planck satellite in the solar system. In particular, they include the zodiacal light emission ("zodi" for short) and also the scattering from the far sidelobes of the beams (FSL). More on this below.<br />
<br />
=== HFI processing ===<br />
<br />
The mapmaking and calibration process is described in detail in the [[Map-making_LFI | mapmaking]] section and in the {{PlanckPapers|planck2016-XLVI}} paper, where detailed references can be found. In brief, the timelines are cleaned and calibrated and converted into HealPix rings (HPRs), then ''SRoll'' is applied to destripe them in polarised space (removal of very low frequency noise by minimising differences at ring crossing points), to remove knows systematic effects (including the flux calibration), and to project them onto a HealPix map.<br />
<br />
The processing yields maps of the signal, hit counts and auto- and cross-variance maps for the 6 full channel and for a pseudo-channel built from the 353 PSBs only. For each channel HFI provides <br />
* a map for the full mission<br />
* two maps for each half-mission<br />
* two maps for built from odd or even rings only<br />
<br />
for a total of 35 maps. <br />
<br />
==== PR3 HFI products ====<br />
<br />
===== Healpix Pixel Rings (HPRs) =====<br />
''SRoll'' main products are the HFI frequency maps. Nevertheless, we also make available the Healpix Pixel Rings (HPRs) of those maps, ie. the data before projection. See [[Healpix_Rings_HFI| description of those files]].<br />
<br />
===== Frequency maps =====<br />
<br />
The 35 HFI frequency maps of the PR3 Legacy Release are the followings:<br />
<br />
{| border="1" cellpadding="3" cellspacing="0" align="center" style="text-align:left" width=800px<br />
|+ '''PR3 HFI frequency maps'''<br />
|- bgcolor="ffdead"<br />
!<br />
!100 GHz<br />
!143 GHz<br />
!217 GHz<br />
!353 GHz<br />
!353_PSB GHz<br />
!545 GHz<br />
!857 GHz<br />
|-<br />
| Full mission<br />
| I, Q, U<br />
| I, Q, U<br />
| I, Q, U<br />
| I, Q, U<br />
| I, Q, U<br />
| I<br />
| I<br />
|-<br />
| Half mission 1<br />
| I, Q, U<br />
| I, Q, U<br />
| I, Q, U<br />
| I, Q, U<br />
| I, Q, U<br />
| I<br />
| I<br />
|-<br />
| Half mission 2<br />
| I, Q, U<br />
| I, Q, U<br />
| I, Q, U<br />
| I, Q, U<br />
| I, Q, U<br />
| I<br />
| I<br />
|-<br />
| Odd rings<br />
| I, Q, U<br />
| I, Q, U<br />
| I, Q, U<br />
| I, Q, U<br />
| I, Q, U<br />
| I<br />
| I<br />
|-<br />
| Even rings<br />
| I, Q, U<br />
| I, Q, U<br />
| I, Q, U<br />
| I, Q, U<br />
| I, Q, U<br />
| I<br />
| I<br />
|}<br />
<br />
See [[Frequency_maps|description of those files]]. These maps are available on the [[https://www.cosmos.esa.int/web/planck/pla| Planck Legacy Archive]].<br />
<br />
<br />
=== LFI processing ===<br />
LFI maps were constructed with the MADAM mapmaking code, version 3.7.4. The code is based on a generalized destriping technique, where the correlated noise component is modelled as a sequence of constant offsets, called "baselines". A noise filter was used to constrain the baseline solution, allowing the use of 0.25-s and 1-s baselines for the 30 and 44GHz, and 70 GHz channels, respectively. See section 6 of {{PlanckPapers|planck2016-l02}}.<br />
<br />
<br />
Radiometers were combined according to the horn-uniform weighting scheme to minimize systematics. The flagged samples were excluded from the analysis by setting their weights to <i>C</i><sub>w</sub><sup>-1</sup> = 0. The Galaxy region was masked out in the destriping phase, to reduce errors arising from strong signal gradients. The polarization component was included in the analysis. <br />
<br />
; Dipole and Far Side Lobe correction: Input timelines are cleaned by the 4&pi;-convolved dipole and Galactic stray light, obtained as a convolution of the 4&pi; in-band far sidelobes and Galactic simulations, as explained in {{PlanckPapers|planck2016-l02}}. <br />
<br />
Scaling of the maps due to beam effects is taken into account in the LFI's beam functions (as provided in [[The_RIMO|the RIMO]]) which should be used for analysis of diffuse components.<br />
<br />
; Bandpass leakage correction :LFI high-resolution maps have been reseleased corrected for bandpass leakage or uncorrected. Further details about the procedure used to generate the bandpass correction maps can be found in section 7 of {{PlanckPapers|planck2016-l02}}.<br />
<br />
; Map zero-level : The 30, 44 and 70 GHz, maps are corrected for a zero-level monopole by applying an offset correction (see the LFI Calibration paper, {{PlanckPapers|planck2014-a06}}). Note that the offset applied is indicated in the header as a comment keyword.<br />
<br />
A detailed description of the mapmaking procedure is given in {{PlanckPapers|planck2013-p02}}, {{PlanckPapers|planck2014-a03}}, {{PlanckPapers|planck2014-a07}} and in the [[Map-making LFI#Map-making|Mapmaking]] section here, in {{PlanckPapers|planck2016-l02}} only a summary is reported.<br />
<br />
==Types of map ==<br />
<br />
=== Full-mission, full-channel maps (7 HFI, 4 LFI)===<br />
<br />
Full channel maps are built using all the valid detectors of a frequency channel and cover either the full or the nominal mission. For HFI, the 143-8 and 545-3 bolometers are rejected entirely, since they are seriously affected by RTS noise. HFI provides the Q and U components for the 100, 143, 217 and 353 GHz channels only. LFI provides the <i>I</i>, <i>Q</i>, and <i>U</i> maps for all the channels. Note that the HFI and LFI <i>Q</i> and <i>U</i> maps are corrected for bandpass leakage, version without correction for LFi is also provided. The <i>I</i>, <i>Q</i>, and <i>U</i> maps are displayed in the figures below. The colour range here is set using a histogram equalization scheme (from HEALPix) that is useful for these non-Gaussian data fields. For visualization purposes, the <i>Q</i> and <i>U</i> maps shown here have been smoothed with a 1&deg; Gaussian kernel, otherwise they look like noise to the naked eye. The 70 GHz full map is also available at <i>N</i><sub>side</sub>=2048.<br />
<br />
The high dynamic range colour scheme of the Planck maps is described [https://wiki.cosmos.esa.int/planck-legacy-archive/index.php/Planck_high_dynamic_range_colour_palette here].<br />
<br />
<center><br />
<gallery style="padding:0 0 0 0;" perrow=3 widths=260px heights=160px> <br />
File: LFI_030GHz_dx12_I.png| '''Full mission <i>I</i>, 30 GHz.'''<br />
File: LFI_044GHz_dx12_I.png| '''Full mission <i>I</i>, 44 GHz.'''<br />
File: LFI_070GHz_dx12_I.png| '''Full mission <i>I</i>, 70 GHz.'''<br />
File: SkyMap100e.png| '''Full mission <i>I</i>, 100 GHz.'''<br />
File: SkyMap143e.png| '''Full mission <i>I</i>, 143 GHz.'''<br />
File: SkyMap217e.png| '''Full mission <i>I</i>, 217 GHz.'''<br />
File: SkyMap353e.png| '''Full mission <i>I</i>, 353 GHz.'''<br />
File: SkyMap545e.png| '''Full mission <i>I</i>, 545 GHz.'''<br />
File: SkyMap857e.png| '''Full mission <i>I</i>, 857 GHz.'''<br />
</gallery><br />
</center><br />
<br><br />
<center><br />
<gallery style="padding:0 0 0 0;" perrow=3 widths=260px heights=160px> <br />
File: LFI_030GHz_dx12_Q.png| '''Full mission <i>Q</i>, 30 GHz.'''<br />
File: LFI_044GHz_dx12_Q.png | '''Full mission <i>Q</i>, 44 GHz.'''<br />
File: LFI_070GHz_dx12_Q.png | '''Full mission <i>Q</i>, 70 GHz.'''<br />
File: HFI_Skymap_100_full_bplcorrected_sm1deg_Qb.png | '''Full mission <i>Q</i>, 100 GHz.'''<br />
File: HFI_Skymap_143_full_bplcorrected_sm1deg_Qb.png | '''Full mission <i>Q</i>, 143 GHz.'''<br />
File: HFI_Skymap_217_full_bplcorrected_sm1deg_Qb.png | '''Full mission <i>Q</i>, 217 GHz.'''<br />
File: HFI_Skymap_353_full_bplcorrected_sm1deg_Qb.png | '''Full mission <i>Q</i>, 353 GHz.'''<br />
</gallery><br />
</center><br />
<br><br />
<center><br />
<gallery style="padding:0 0 0 0;" perrow=3 widths=260px heights=160px> <br />
File: LFI_030GHz_dx12_U.png| '''Full mission <i>U</i>, 30 GHz.'''<br />
File: LFI_044GHz_dx12_U.png | '''Full mission <i>U</i>, 44 GHz.'''<br />
File: LFI_070GHz_dx12_U.png | '''Full mission <i>U</i>, 70 GHz.'''<br />
File: HFI_Skymap_100_full_bplcorrected_sm1deg_Ub.png | '''Full mission <i>U</i>, 100 GHz.'''<br />
File: HFI_Skymap_143_full_bplcorrected_sm1deg_Ub.png | '''Full mission <i>U</i>, 143 GHz.'''<br />
File: HFI_Skymap_217_full_bplcorrected_sm1deg_Ub.png | '''Full mission <i>U</i>, 217 GHz.'''<br />
File: HFI_Skymap_353_full_bplcorrected_sm1deg_Ub.png | '''Full mission <i>U</i>, 353 GHz.'''<br />
</gallery><br />
<br />
</center><br />
<br />
=== Full mission light maps, full channel maps (7 HFI, 7 LFI)===<br />
<br />
These maps are based on the Full mission maps but contain fewer columns, IQU from 30 to 353 GHz, and I only at 545 and 857 GHz. These maps have been produced to reduce the transfer time of the most downloaded frequency full mission maps.<br />
<br />
=== Single-survey, full-channel maps (35 LFI)===<br />
<br />
Single-survey maps are built using all valid detectors of a frequency channel; they separately cover the different sky surveys. The surveys are defined as the times over which the satellite spin axis rotates by 180&deg;, which, due to the position of the detectors in the focal plane does not cover the full sky, but a fraction between about 80% and 90%, depending on detector position. During adjacent surveys the sky is scanned in opposite directions (more precisely it is the ecliptic equator that is scanned in opposite directions). While these are useful to investigate variable sources, they are also used to study the systematics of the time-response of the detectors as they scan bright sources, like the Galactic Plane, in different directions during different survey. Note that the HFI and LFI missions cover five and eight surveys, respectively, and in the case of HFI the last survey in incomplete.<br />
The 70 GHz survey maps are available also at <i>N</i><sub>side</sub>=2048. Note that LFI provides a special survey-map combination used in the low-&#8467; analysis; this maps, available at the three LFI frequencies, 30, 44, and 70 GHz, was built using the combination of Surveys 1, 3, 5, 6, 7, and 8.<br />
<br />
=== Year maps, full-channel maps (16 LFI)===<br />
<br />
These maps are built using the data of Surveys 1+2, Surveys 3+4, and so forth. They are used to study long-term systematic effects. The 70 GHz years maps are available also at <i>N</i><sub>side</sub>=2048.<br />
<br />
===Half-mission maps, full-channel maps (14 HFI, 12 LFI)===<br />
<br />
For HFI, the half mission is defined after eliminating those rings that are discarded for all bolometers, many of which occurred during the 5th survey when the "End-of-Life" tests were performed. The remaining rings are divided in half to define the two halves of the mission. This exercise is done for the full mission only.<br />
<br />
For LFI, instead of the half-mission maps, the following year combinations have been created: Year 1+2, Year 1+3, Year 2+4, Year 3+4,<br />
<br />
===Full mission, single-detector maps (22 LFI)===<br />
<br />
For LFI, all the 22 Radiometers maps are available, and (obviously) only in Stokes <i>I</i>.<br />
<br />
===Full-mission, detector-set or detector-pairs maps (8 LFI)===<br />
<br />
The objective here is to build independent temperature (<i>I</i>) and polarization (<i>Q</i> and <i>U</i>) maps using the two pairs of polarization-sensitive detectors of each channel where they are available, i.e., for the 44-353 GHz channels. The table below indicates which detectors were used to build each detector set (detset).<br />
<br />
{| border="1" cellpadding="3" cellspacing="0" align="center" style="text-align:left" width=600px<br />
|+ '''Definition of LFI detector pairs'''<br />
|- bgcolor="ffdead" <br />
!Frequency || Horn pair || Comment <br />
|-<br />
|44 GHz || 24 || This map is only in temperature<br />
|-<br />
|44 GHz || 25 and 26 || <br />
|-<br />
|70 GHz || 18 and 23 || Available also at <i>N</i><sub>side</sub>=2048<br />
|-<br />
|70 GHz || 19 and 22 || Available also at <i>N</i><sub>side</sub>=2048<br />
|-<br />
|70 GHz || 20 and 21 || Available also at <i>N</i><sub>side</sub>=2048<br />
|}<br />
<br />
===Half-ring maps (62 LFI)===<br />
<br />
These maps are similar to the ones described above, but are built using only the first or the second halves of each ring (or pointing period). The HFI provides half-ring maps for the full mission only, as well as for the full channel, the detsets, and the single bolometers. The LFI provides half-ring maps for the full mission in each channel (70 GHz also at <i>N</i><sub>side</sub>=2048), for the full-mission radiometers, and for the full-mission horn pairs.<br />
<br />
=== Odd and even rings maps (14 HFI)<br />
<br />
As the name indicates, these are generated by using only the odd or only the even rings.<br />
<br />
=== Caveats and known issues ===<br />
<br />
'''TBC'''<br />
<br />
==== Caveats when using the HFI frequency maps ====<br />
Some imperfections have shown up in the tests of the HFI PR3 maps that were previously hidden by higher-level systematics in the previous PR2 data. These lead to guidelines for the proper use of the HFI PR3 data.<br />
<br />
===== Monopoles =====<br />
Monopoles, which cannot be extracted from Planck data alone, are adjusted at each frequency (as was done in the previous PR2 release). For component separation, this provides maps that can be used directly in combination with other tracers.<br />
This monopole includes a CIB model, a diffuse ISM signal adjusted on the HI tracer, and a zodiacal emission signal adjusted to the proper absolute intensity.<br />
<br />
=====Use of the 353 GHz SWBs ===== <br />
We deliver two data sets: the recommended one not using the 353 GHz SWBs data, and the other one including the 353 GHz SWBs for specific use like, for example, increasing the signal to noise level at high multipoles.<br />
<br />
===== Color correction and component separation=====<br />
Different responses between bolometers to different foregrounds cannot be used with the PR3 release to extract component maps. Single bolometer maps computed by Sroll in a frequency band, are all adjusted by construction to the band average response.<br />
<br />
===== Sub-pixel effect in very bright regions===== <br />
The bandpass corrections have been optimized for high latitude regions which implied to reduce the noise of the CO and dust bandpass templates to avoid the introduction of significant correlated noise. The effect is negligible for dust but not for CO in very bright regions. See [[subpixel_HFI|detailled description]].<br />
<br />
===== Solar dipole residual===== <br />
The ''Planck'' 2015 Solar dipole is removed from the PR3 HFI maps to be consistent with LFI maps and to facilitate comparison with the previous PR2 ones. The best Solar dipole determination from HFI PR3 data shows a small shift in direction of about 1', but a 1.8 &mu;K lower amplitude. Removal of the ''Planck'' 2015 Solar dipole thus leaves a small but non-negligible dipole residual in the HFI PR3 maps. To correct for this, and adjust maps at the best photometric calibration, users of the HFI PR3 maps should:<br />
# put back into the maps the ''Planck'' 2015 Solar dipole (d,l,b)= (3364.5 &plusmn; 2.0 &mu;K, 264.00 &plusmn; 0.03&deg;, 48.24 &plusmn; 0.02&deg;),<br />
# include the [[#Calibration accuracy|absolute calibration frequency bias]], i.e., multiply by 1 minus the calibration bias,<br />
# lastly, remove the [[#HFI 2018 Solar dipole|HFI 2018 Solar dipole]].<br />
<br />
==Inputs==<br />
=== HFI inputs ===<br />
<br />
The HFI mapmaking takes as input:<br />
* the cleaned TOIs of the signal from each detector, together with their flags, produced by the [[TOI processing|TOI processing]] pipeline;<br />
* the TOIs of pointing (quaternions), described in [[Detector_pointing|Detector pointing]];<br />
* bolometer-level characterization data, from the DPC's internal IMO (not distributed);<br />
* Planck orbit data, used to compute and remove the Earth's dipole;<br />
* Planck solar dipole information, used to calibrate the CMB channels;<br />
* planet models used to calibrate the Galactic channels.<br />
<br />
=== LFI inputs ===<br />
<br />
The MADAM mapmaker takes as input:<br />
* the calibrated timelines (for details see [[TOI processing LFI|TOI Processing]]);<br />
* the detector pointings (for details see [[Detector_pointing|Detector pointing]]);<br />
* the noise information in the form of 3-parameter (white noise level &sigma;, slope, and knee frequency <i>f</i><sub>knee</sub>) noise model (for details see [[The RIMO|RIMO]]).<br />
<br />
==Related products==<br />
=== Masks ===<br />
This section presents the "general purpose" masks. Other masks specific to certain products are packaged with those products.<br />
<br />
Note that for this release, HFI has not produced any new masks. <br />
<br />
==== Gatactic Centre masks ====<br />
<br />
'''TBW'''<br />
<br />
<br />
====Point source masks [TO BE REMOVED ??]====<br />
<br />
For HFI and LFI two sets of point-source masks are provided. <br />
* Intensity masks, which remove sources detected with S/N > 5. <br />
* Polarisation masks, which remove sources that have polarization detection significance levels of 99.97 % or greater at the position of a source detected in intensity. They were derived from the polarization maps with dust foreground bandpass mismatch leakage corrections applied. The area excised around each source has a radius of 3σ (width) of the beam, i.e., 1.27 FWHM (for LFI the cut around each source has a radius of 32 arcmin at 30GHz, 27 arcmin at 44 GHz, and 13 arcmin at 70 GHz).<br />
<br />
Both sets of masks are found in the files ''HFI_Mask_PointSrc_2048_R2.00.fits'' and ''LFI_Mask_PointSrc_2048_R2.00.fits'', in which the first extension contains the intensity masks, and the second contains the polarization masks.<br />
<br />
====Galactic plane masks [TO BE REMOVED ??]====<br />
<br />
Eight Galactic emission masks are provided, giving 20, 40, 60, 70, 80, 90, 97, and 99% sky coverage, derived from the 353 GHz map after CMB subtraction. These are independent of frequency channel. Three versions are given: not apodized; and apodized by 2&deg; and 5&deg;. The filenames are ''HFI_Mask_GalPlane-apoN_2048_R2.00.fits'', where <i>N</i> = 0, 2, and 5.<br />
<br />
The masks are shown below. The eight "GalPlane" masks are combined (added together) and shown in a single figure for each of the three apodizations. While the result is quite clear for the case of no apodization, it is less so for the apodized case. The "PointSrc" masks are shown separately for the intensity case.<br />
<br />
<center><br />
<gallery perrow=3 widths=260px heights=160px ><br />
File: GalPlaneMask_apo0.png | '''Galactic plane masks, no apodization.'''<br />
File: GalPlaneMask_apo2.png | '''Galactic plane masks, apodized to 2&deg;.'''<br />
File: GalPlaneMask_apo5.png | '''Galactic plane masks, apodized to 5&deg;.'''<br />
File: PointSrcMask_100.png | '''Point source mask, 100 GHz.'''<br />
File: PointSrcMask_143.png | '''Point source mask, 143 GHz.'''<br />
File: PointSrcMask_217.png | '''Point source mask, 217 GHz.'''<br />
File: PointSrcMask_353.png | '''Point source mask, 343 GHz.'''<br />
File: PointSrcMask_545.png | '''Point source mask, 545 GHz.'''<br />
File: PointSrcMask_857.png | '''Point source mask, 857 GHz.'''<br />
</gallery><br />
</center><br />
<br />
== File names ==<br />
The FITS filenames are of the form ''{H|L}FI_SkyMap_fff{-tag}_Nside_R3.nn_{coverage}-{type}.fits'', where "fff" are three digits to indicate the Planck frequency band, "tag" indicates the single detector or the detset (no "tag" indicates full channel), "Nside" is the HEALPix <i>N</i><sub>side</sub> value of the map, "coverage" indicates which part of the mission is covered (full, half mission, survey, year, etc.), and the optional "type" indicates the subset of input data used. The table below lists the products by type, with the appropriate unix wildcards that form the full filename.<br />
<br />
{| class="wikitable" align="center" style="text-align"left" border="1" cellpadding="15" cellspacing="20" width=880px<br />
|+ '''HFI FITS filenames'''<br />
|- bgcolor="ffdead"<br />
! Coverage || Filename <br />
|-<br />
| Full channel, full mission ||HFI_SkyMap_fff{-tag}_2048_R3.??_full.fits<br />
|-<br />
| Full channel, half mission || HFI_SkyMap_fff{-tag}_2048_R3.??_halfmission-{1/2}.fits<br />
|-<br />
| Full channel, full mission, odd/even ring || HFI_SkyMap_fff{-tag}_2048_R3.??_{odd/even}ring.fits <br />
|}<br />
<br />
{| class="wikitable" align="center" style="text-align"left" border="1" cellpadding="15" cellspacing="20" width=1400px<br />
|+ '''LFI FITS filenames'''<br />
|- bgcolor="ffdead"<br />
! Coverage || Filename || Half-ring filename || Comment<br />
|-<br />
| Full channel, full mission ||LFI_SkyMap_???_1024_R3.??_full.fits ||LFI_SkyMap_???_1024_R2.??_full-ringhalf-?.fits || 70GHz is corrected for Template<br />
|-<br />
| Full channel, full mission BandPass corrected ||LFI_SkyMap_???-BPassCorrected_1024_R3.??_full.fits ||LFI_SkyMap_???-BPassCorrected_???_1024_R2.??_full-ringhalf-?.fits || 70GHz is corrected for Template<br />
|-<br />
| Full channel, single survey || LFI_SkyMap_???_1024_R3.??_survey-?.fits || n/a || n/a<br />
|-<br />
| Full channel, survey combination || LFI_SkyMap_???_1024_R3.??_survey-1-3-5-6-7-8.fits || n/a || n/a<br />
|-<br />
| Full channel, survey combination BandPass corrected|| LFI_SkyMap_???_1024_R3.??-BPassCorrected_survey-1-3-5-6-7-8.fits || n/a || n/a<br />
|-<br />
| Full channel, single year || LFI_SkyMap_???_1024_R3.??_year-?.fits || n/a || n/a<br />
|-<br />
| Full channel, single year BandPass corrected|| LFI_SkyMap_???-BPassCorrected_1024_R3.??_year-?.fits || n/a || n/a<br />
|-<br />
| Full channel, year combination || LFI_SkyMap_???_1024_R3.??_year?-?.fits || n/a || n/a<br />
|-<br />
| Full channel, year combination BandPass corrected|| LFI_SkyMap_???-BPassCorrected_1024_R3.??_year?-?.fits || n/a || n/a<br />
|-<br />
| Horn pair, full mission || LFI_SkyMap_???-??-??_1024_R3.??_full.fits || LFI_SkyMap_???_??-??_1024_R3.??_full-ringhalf-?.fits || n/a<br />
|-<br />
| Single radiometer, full mission || LFI_SkyMap_???-???_1024_R3.??_full.fits || LFI_SkyMap_???-???_1024_R3.??_full-ringhalf-?.fits || n/a<br />
|}<br />
<br />
For the benefit of users who are only looking for the frequency maps with no additional information, we also provide a file combining the nine frequency maps as separate columns in a single extension. The nine columns in this file contain the intensity maps <i>only</i> and no other information (hits maps or variance maps) is provided.<br />
<br />
== FITS file structure ==<br />
<br />
The FITS files for the sky maps contain a minimal primary header with no data, and a ''BINTABLE'' extension (EXTENSION 1, EXTNAME = ''FREQ-MAP'') containing the data. The structure is shown schematically in the figure below. The ''FREQ-MAP'' extension contains a 3- or 10-column table that contain the signal, hit-count, and variance maps, all in HEALPix format. The 3-column case is for intensity only maps, while the 10-column case is for polarization. The number of rows is the number of map pixels, which is <i>N</i><sub>pix</sub> = 12 <i>N</i><sub>side</sub><sup>2</sup> for HEALPix maps, where <i>N</i><sub>side</sub> = 1024 or 2048 for most the maps presented in this section.<br />
<br />
[[File:FITS_FreqMap.png | 550px | center | thumb | '''FITS file structure.''']]<br />
<br />
Note that file sizes are approximately 0.6 GB for <i>I</i>-only maps and 1.9 GB for <i>IQU</i> maps at <i>N</i><sub>side</sub>=2048, but about 0.14 GB for <i>I</i>-only maps and 0.45 GB for <i>IQU</i> maps at <i>N</i><sub>pix</sub>=1024 .<br />
<br />
Keywords indicate the coordinate system ("GALACTIC"), the HEALPix ordering scheme ("NESTED"), the units (K<sub>CMB</sub> or MJy.sr<sup>-1</sup>) of each column, and of course the frequency channel ("FREQ"). Where polarization <i>Q</i> and <i>U</i> maps are provided, the "COSMO" polarization convention (used in HEALPix) is adopted, and it is specified in the "POLCCONV" keyword (see [[Sky_temperature_maps#Polarization_convention_used_in_the_Planck_project|this section]]). The "COMMENT" fields give a one-line summary of the product, and some other information useful for traceability within the DPCs. The original filename is also given in the "FILENAME" keyword. The "BAD_DATA" keyword gives the value used by HEALPix to indicate pixels for which no signal is present (these will also have a hit-count value of 0). The main parameters are summarized in the table below.<br />
<br />
{| border="1" cellpadding="3" cellspacing="0" align="center" style="text-align:left" width=800px<br />
|+ '''Sky map file data structure'''<br />
|- bgcolor="ffdead" <br />
!colspan="4" | 1. EXTNAME = 'FREQ-MAP' : Data columns<br />
|- bgcolor="ffdead" <br />
! Column name || Data type || Units || Description<br />
|-<br />
|I_STOKES || Real*4 || K<sub>CMB</sub> or MJy.sr<sup>-1</sup> || Stokes <i>I</i> map<br />
|-<br />
|Q_STOKES || Real*4 || K<sub>CMB</sub> or MJy.sr<sup>-1</sup> || Stokes <i>Q</i> map (optional)<br />
|-<br />
|U_STOKES || Real*4 || K<sub>CMB</sub> or MJy.sr<sup>-1</sup> || Stokes <i>U</i> map (optional)<br />
|-<br />
|HITS || Int*4 || none || The hit-count map<br />
|-<br />
|II_COV || Real*4 || K<sub>CMB</sub><sup>2</sup> or (MJy.sr<sup>-1</sup>)<sup>2</sup> || <i>II</i> variance map<br />
|-<br />
|IQ_COV || Real*4 || K<sub>CMB</sub><sup>2</sup> or (MJy.sr<sup>-1</sup>)<sup>2</sup> || <i>IQ</i> variance map (optional)<br />
|-<br />
|IU_COV || Real*4 || K<sub>CMB</sub><sup>2</sup> or (MJy.sr<sup>-1</sup>)<sup>2</sup> || <i>IQ</i> variance map (optional)<br />
|-<br />
|QQ_COV || Real*4 || K<sub>CMB</sub><sup>2</sup> or (MJy.sr<sup>-1</sup>)<sup>2</sup> || <i>QQ</i> variance map (optional)<br />
|-<br />
|QU_COV || Real*4 || K<sub>CMB</sub><sup>2</sup> or (MJy.sr<sup>-1</sup>)<sup>2</sup> || <i>QU</i> variance map (optional)<br />
|-<br />
|UU_COV || Real*4 || K<sub>CMB</sub><sup>2</sup> or (MJy.sr<sup>-1</sup>)<sup>2</sup> || <i>UU</i> variance map (optional)<br />
|-<br />
|- bgcolor="ffdead" <br />
! Keyword || Data type || Value || Description<br />
|-<br />
|PIXTYPE || String || HEALPIX ||<br />
|-<br />
|COORDSYS || String || GALACTIC ||Coordinate system <br />
|-<br />
|ORDERING || String || NESTED || Healpix ordering<br />
|-<br />
|POLCCONV || String || COSMO || Polarization convention<br />
|-<br />
|NSIDE || Int || 1024 or 2048 || HEALPix <i>N</i><sub>side</sub> <br />
|-<br />
|FIRSTPIX || Int*4 || 0 || First pixel number<br />
|-<br />
|LASTPIX || Int*4 || 12 <i>N</i><sub>side</sub><sup>2</sup> – 1 || Last pixel number<br />
|-<br />
|FREQ || String || nnn || Frequency channel <br />
|}<br />
<br />
<br />
The same structure applies to all "SkyMap" products, independent of whether they are full channel, survey of half-ring. The distinction between the types of maps is present in the FITS filename (and in the traceability comment fields).<br />
<br />
==Polarization convention used in the Planck project==<br />
<br />
The FITS keyword "POLCCONV" defines the polarization convention of the data within the file.<br />
The Planck collaboration used the COSMO convention for the polarization angle (as usually adopted in space-based and other CMB missions), whereas other subfields of astronomy usually adopt the IAU convention. The basic difference comes down to whether one thinks of the light rays being emitted from the origin (the usual mathematics/physics convention) or converging on the observer from the sky (the usual astronomy convention), and hence the "obvious" choice is different for a physicists and for an astronomer. Given that CMB results are of interest to a wide range of both physicists and astronomers, there is no single choice of convention that everyone would regard as self-evident. Hence one simply has to be aware of the convention being adopted. Because of this the Planck Collaboration has taken pains to point out which convention is being used in publications and in data releases. In the following we describe the difference between these two conventions, and the consequence if it is <i>not</i> taken into account correctly in the analysis.<br />
<br />
[[File:conventions.png|thumb|center|400px|'''Figure 1. Polarization conventions, showing the COSMO convention (left) and IAU convention (right). The vector <math>\hat{z}</math> points in the outward direction in COSMO, and inwards in IAU. The bottom panel refers to the plane tangent to the sphere.''']]<br />
<br />
Changing the orientation convention is equivalent to a transformation &psi;'=&pi;-&psi; of the polarization angle (Figure 1). The consequence of this transformation is the inversion of the Stokes parameter <i>U</i>.<br />
The components of the polarization tensor in the helicity basis <math>\epsilon^{\pm}=(\hat{x}\pm i\hat{y})/\sqrt{2}</math> are<br />
<br />
<math><br />
(Q+iU)(\hat{n}) = \sum _{\ell m}a_{2,lm}{}_{2}Y_{\ell }^{m}(\hat{n}),<br />
\\(Q-iU)(\hat{n}) = \sum _{\ell m}a_{-2,lm}{}_{2}Y_{\ell }^{m}(\hat{n}),<br />
</math><br />
<br />
where <math>{}_{2}Y_{\ell }^{m}(\hat{n})</math> are the spin-weighted spherical harmonic functions.<br />
The <i>E</i> and <i>B</i> modes can be defined as<br />
<br />
<math><br />
E(\hat{n}) = \sum_{\ell m}a_{E,\ell m}Y_{\ell }^{m}(\hat{n}),<br />
\\B(\hat{n}) = \sum_{\ell m}a_{B,\ell m}Y_{\ell }^{m}(\hat{n}),<br />
</math><br />
<br />
where the coefficients <i>a<sub>E,&#8467;m</sub></i> and <i>a<sub>B,&#8467;m</sub></i> are derived from linear combinations of the <i>a<sub>2,&#8467;m</sub></i>, <i>a<sub>-2,&#8467;m</sub></i>, defined implicitly in the first equation (<i>Q</i>&plusmn; i<i>U</i>).<br />
<br />
[[File:test_gradient.jpg|thumb|center|400px|]]<br />
[[File:test_curl.jpg|thumb|center|400px|'''Figure 2. Error on Planck-LFI 70 GHz <i>EE</i> (top) and <i>BB</i> (bottom) power spectra, in the case of an incorrect choice being made for the polarization coordinate system convention (IAU instead of COSMO).''']]<br />
<br />
The effect of the sign inversion of <i>U</i> on the polarization spectra is a non-trivial mixing of <i>E</i> and <i>B</i> modes. <br />
An example of the typical error on <i>EE</i> and <i>BB</i> auto-spectra in the case of the wrong choice for the polarization basis is shown in Figure 2.<br />
<br />
<i>One should be careful</i> to be aware of the polarization convention that is being adopted. If the IAU convention is used in computing the power spectra, then the sign of the <i>U</i> component of the Planck maps must be inverted before computing the <i>E</i> and <i>B</i> modes.<br />
<br />
In astronomical applications it is common to define a pseudo-vector <i>P</i> to show the amplitude and orientation of<br />
polarization on a map. When plotting these line segments to show the orientation of the plane of polarization (or the orthogonal direction, often considered to be the projection of the magnetic field), the results are the same for both the COSMO and IAU conventions. This because the appearance of <i>P</i> is a property of the radiation and hence not affected by the sign of <i>U</i>.<br />
<br />
=== Note on the convention used in the Planck Catalogue of Compact Sources (PCCS) ===<br />
Planck non-cosmology papers sometimes follow the IAU convention for internal analysis, for ease of comparison with other studies (e.g., comparison of Planck-derived thermal dust emission polarization with the optical polarization of starlight). Nevertheless, Planck data products, such as component-separated maps, still use the COSMO convention. The one exception is for the compact source catalogue. Because catalogues of astronomical objects found by Planck need to be compared directly with other source catalogues, the polarized sources described in the Planck Catalogue of Compact Sources follow the IAU convention, and the polarization angles are defined on an interval of [-90&deg;,90&deg;]. To switch to the COSMO convention, the polarization angles listed in the catalogue should be shifted by 90&deg; and multiplied by -1.<br />
<br />
== References ==<br />
<References /><br />
<br />
<br />
<span style="background:green"><br />
<br />
<span style="background:green"><br />
== Previous releases ==<br />
<br />
<div class="toccolours mw-collapsible mw-collapsed" style="background-color: #FFDAB9;width:80%" ><br />
'''2015 Sky temperature and polarization maps'''<br />
<br />
<div class="mw-collapsible-content"><br />
<br />
<br />
'''General description'''<br />
<br />
Sky maps give the best estimate of the intensity and polarization (Stokes Q and U components), if available, of the signal from the sky after removal, as far as possible, of known systematic effects (mostly instrumental, but including also the solar and earth-motion dipole, Galactic strylight and the Zodiacal light). Sky maps are provided for the full Planck mission using all valid detectors in each frequency channel, and also for various subsets by splitting the mission in various time ranges or in subsets of the detectors in a given channel. These products are useful for the study of source variability, but they are especially interesting for characterisation purposes (see also the [[HFI-Validation | data validation]] section). The details of the start and end of the time ranges are given in the table below.<br />
<br />
To help in further processing, there are also masks of the Galactic Plane and of point sources, each provided for several different depths.<br />
<br />
All sky maps are in Healpix format, with Nside of 1024 (LFI 30, 44 and 70) and 2048 (LFI 70 and HFI), in Galactic coordinates, and Nested ordering. <br />
<br />
;WARNING: the Healpix convention for polarization is NOT the same as the IAU convention - see Section 8 in this page.<br />
<br />
The signal is given in units of K<sub>cmb</sub> for 30-353 GHz, and of MJy/sr (for a constant <math>\nu F_\nu</math> energy distribution ) for 545 and 857 GHz. For each frequency channel, the intensity and polarization maps are packaged into a ''BINTABLE'' extension of a FITS file together with a hit-count map (or hit map, for short, giving the number of observation samples that are cumulated in a pixel, all detectors combined) and with the variance and covariance maps. Additional information is given in the FITS file header. The structure of the FITS file is given in the [[#FITS_file_structure | FITS file structure]] section below. <br />
<br />
; R2.00 : this first release (Jan 2015) contains polarisation data for the 353 GHz channel only.<br />
; R2.01 : this second release (May 2015) adds polarisation data to the 100-217 GHz channels.<br />
; R2.02 : a full re-release to correct the Healpix bad pixel value in the maps which was altered during the preparation of the maps and not reset to the correct value (the valid pixels are unchanged). It also fixes some FITS keywords, and includes a full re-release of the Zodi correction maps, with the 100-217 GHz one now including the polarisation correction)<br />
<br />
{| border="1" cellpadding="3" cellspacing="0" align="center" style="text-align:left" width=800px<br />
|+ '''Ranges for mission and surveys'''<br />
|- bgcolor="ffdead" <br />
! Range || ODs || HFI rings || pointing-IDs || Comment<br />
|-<br />
|nominal mission || 91 - 563 || 240 - 14723 || 00004200 - 03180200 ||<br />
|-<br />
|full mission || 91 - 974 || 240 - 27005 || 00004200 - 05322620 || for HFI<br />
|-<br />
|full mission || 91 - 1543 || n/a || 00004200 - 06511160 || for LFI<br />
|-<br />
|Survey 1 || 91 - 270 || 240 - 5720 || 00004200 - 01059820 ||<br />
|-<br />
|Survey 2 || 270 - 456 || 5721 - 11194 || 01059830 - 02114520 ||<br />
|-<br />
|Survey 3 || 456 - 636 || 11195 - 16691 || 02114530 - 03193660 ||<br />
|-<br />
|Survey 4 || 636 - 807 || 16692 - 21720 || 03193670 - 04243900 ||<br />
|-<br />
|Survey 5 || 807 - 974 || 21721 - 27005 || 05267180 - 05322590 || end of mission for HFI<br />
|-<br />
|Survey 5 || 807 - 993 || n/a || 05267180 - 06344800 || end of survey for LFI<br />
|-<br />
|Survey 6 || 993 - 1177 || n/a || 06344810 - 06398120 || LFI only <br />
|-<br />
|Survey 7 || 1177 - 1358 || n/a || 06398130 - 06456410 || LFI only <br />
|-<br />
|Survey 8 || 1358 - 1543 || n/a || 06456420 - 06511160 || LFI only <br />
|-<br />
|Survey 9 || 1543 - 1604 || n/a || 06511170 - 06533320 || LFI only Not in this delivery<br />
|-<br />
|HFI mission-half-1 || 91 - 531 || 240 - 13471 || 00004200 - 03155580 ||<br />
|-<br />
|HFI mission-half-2 || 531 - 974 || 13472 - 27005 || 03155590 - 05322590 ||<br />
|-<br />
|LFI Year 1 || 91 - 456 || n/a || 00004200 - 02114520 ||<br />
|-<br />
|LFI Year 2 || 456 - 807 || n/a || 02114530 - 04243900 ||<br />
|-<br />
|LFI Year 3 || 807 - 1177 || n/a || 05267180 - 06398120 ||<br />
|-<br />
|LFI Year 4 || 1177 - 1543 || n/a || 06398130 - 06511160 ||<br />
|-<br />
|}<br />
<br />
'''Production process'''<br />
<br />
Sky maps are produced by combining appropriately the data of all working detectors in a frequency channel over some period of the mission. They give the best estimate of the signal from the sky (unpolarised) after removal, as far as possible, of known systematic effects and of the dipole signals induced by the motion of the solar system in the CMB and of the Planck satellite in the solar system. In particular, they include the Zodiacal light emission (Zodi for short) and also the scattering from the far-side lobes of the beams (FSL). More on this below.<br />
<br />
''' HFI processing '''<br />
<br />
The mapmaking and calibration process is described in detail in the [[Map-making_LFI | Map-making]] section and in the {{PlanckPapers|planck2014-a09}} paper, where detailed references are found. In brief it consists of:<br />
<br />
; binning the TOI data onto ''rings'' : Healpix rings (HPRs) are used here, each ring containing the combined data of one pointing period. <br />
; flux calibration : at 100-353 GHz, the flux calibration factors are determined by correlating the signal with the orbital dipole, which is determined very accurately from the Planck satellite orbital parameters provided by Flight Dynamics. This provides a single gain factor per bolometer. At 545 and 857 GHz the gain is determined from the observation of Uranus and Neptune (but not Jupiter which is too bright) and comparison to recent models made explicitly for this mission. A single gain is applied to all rings at these frequencies.<br />
; destriping : in order to remove low-frequency noise, an offset per ring is determined by minimizing the differences between HPRs at their crossings, and removed.<br />
; Zodiacal light correction : a Zodiacal light model is used to build HPRs of the the Zodi emission, which is subtracted from the calibrated HPRs.<br />
; projection onto the map : the offset-corrected, flux-calibrated, and Zodi-cleaned HPRs are projected onto Healpix maps, with the data of each bolometer weighted by a factor of 1/NET of that bolometer.<br />
<br />
These steps are followed by some post-processing which is designed to prepare the maps for the component separation work. This post processing consists of: <br />
<br />
; Dust bandpass leakage correction : the Q and U maps are corrected for the intensity-to-polarisation leakage caused by the foregrounds having a non-CMB spectrum, and as a consequence of the non-identical bandpasses on the different detectors (bandpass mismatch, or BPM). This correction is determined using the ''ground'' method as described in Section 7.3 of {{PlanckPapers|planck2014-a09}}. These correction maps can be found in the Planck Legacy Archive as ''HFI_CorrMap_???-dustleak-ground_2048_R2.0?_{coverage}.fits''. The correction is applied by subtracting the correction map from the corresponding input map. This correction is not applied to the nominal mission maps in order to maintain compatibility with the PR1 products. ''In fact this correction was computed and applied only to the products used in component separation'', so they were not applied to the single survey maps and to the half-ring maps, which are considered characterisation products.<br />
; Far Side Lobe calibration correction : the 100-217 maps are multiplied by factors of 1.00087, 1.00046, and 1.00043, respectively, to compensate for the non-removal of the far-side lobes, and similarly the corresponding covariance maps have also been corrected by multiplication by the square of the factor.<br />
; Fill missing pixels : missing pixels are filled in with a value that is the mean of valid pixels within a given radius. A radius of 1 deg is used for the full channel maps, and 1.5 deg is used for the detset maps. This step is not applied to the single survey maps since they have large swaths of the sky that are not covered.<br />
<br />
; Map zero-level : for the 100 to 857 GHz maps, the zero levels are set to their optimal levels for Galactic and CIB studies. A procedure for adjusting them to astrophysical values is given in the HFI Mapmaking and Calibration paper {{PlanckPapers|planck2014-a09}}.<br />
<br />
These maps provide the main mission products. Together with signal maps, hit count, variance, and variance maps are also produced. The hit maps give the (integer) number of valid TOI-level samples that contribute to the signal of each pixel. All valid samples are counted in the same way, i.e., there is no weighting factor applied. The variance maps project the white noise estimate, provided by the NETs, in the sky domain.<br />
<br />
Note that the nominal mission maps have not had the post-processing applied, which makes them more easily comparable to the PR1 products.<br />
<br />
''' LFI processing '''<br />
LFI maps were constructed with the Madam map-making code, version 3.7.4. The code is based on generalized destriping technique, where the correlated noise component is modeled as a sequence of constant offset, called baselines. A noise filter was used to constrain the baseline solution allowing the use of 0.25 s and 1 second baselines for the 30 and 44, 70 GHz respectively.<br />
<br />
Radiometers were combined according to the horn-uniform weighting scheme to minimize systematics. The used weights are listed in [[Map-making LFI#Map-making|Map-making]]. The flagged samples were excluded from the analysis by setting their weights to <math>C_{w}^{-1}</math> = 0. The galaxy region was masked out in the destriping phase, to reduce error arising from strong signal gradients. The polarization component was included in the analysis... <br />
<br />
; Dipole and Far Side Lobe correction : input timelines are cleaned by 4pi convolved dipole and Galactic Straylight obtained as convolution of the 4pi in band far sidelobes and Galactic Simulation as explained in Section 7.4 of {{PlanckPapers|planck2014-a03}}. <br />
<br />
Beam effects on the LFI maps are described in Section 7.1 of {{PlanckPapers|planck2014-a03}}. Scaling of the maps due to beam effects is taken into account in the LFI's beam functions (as provided in the RIMO, give reference) which should be used for analysis of diffuse components. To compute the flux densities of compact sources, correction must be made for beam effects (see Table 8 of {{PlanckPapers|planck2014-a03}})."<br />
<br />
; Bandpass leakage correction : '''as opposed to the HFI, the LFI high resolution maps have not been corrected for bandpass leakage. Only low resolution (nside 256) maps are provided with the bandpass correction'''. The correction maps (LFI_CorrMap_0??-BPassCorr_*.fits) can be found in the Planck Legacy Archive. Further details about the procedure used to generate the bandpass correction maps can be found in Section 11 of {{PlanckPapers|planck2014-a03}}.<br />
<br />
; Map zero-level : for the 30, 44 and 70 GHz, maps are corrected for zero level monopole by applying an offset correction, see LFI Calibration paper {{PlanckPapers|planck2014-a06}}. Note that the offset applied is indicated in the header as a comment keyword.<br />
<br />
A detailed description of the map-making procedure is given in {{PlanckPapers|planck2013-p02}}, {{PlanckPapers|planck2014-a03}}, {{PlanckPapers|planck2014-a07}} and in section [[Map-making LFI#Map-making|Map-making]].<br />
<br />
'''Types of maps '''<br />
<br />
''' Full mission, full channel maps (6 HFI, 4 LFI)'''<br />
<br />
Full channel maps are built using all the valid detectors of a frequency channel and cover the either the full or the nominal mission. For HFI, the 143-8 and 545-3 bolometers are rejected entirely as they are seriously affected by RTS noise. HFI provides the Q and U components for the 100, 143, 217 and 353 GHz channels only. LFI provides the I, Q and U maps for all the channels. Reminder: HFI Q and U maps are corrected for bandpass leakage but LFI Q and U maps are not. The I, Q and U maps are displayed in the figures below. The color range is set using a histogram equalisation scheme (from HEALPIX) that is useful for these non-Gaussian data fields. For visualization purposes, the Q and U maps shown here have been smoothed with a 1 degree Gaussian kernel, otherwise they look like noise to the naked eye.<br />
The 70 GHz full map is available also at <math>N_{side}</math> 2048.<br />
<br />
<center><br />
<gallery style="padding:0 0 0 0;" perrow=3 widths=260px heights=160px> <br />
File: SkyMap30e.png| '''Full mission I, 30 GHz'''<br />
File: SkyMap44e.png | '''Full mission I, 44 GHz'''<br />
File: SkyMap70e.png | '''Full mission I, 70 GHz'''<br />
File: SkyMap100e.png | '''Full mission I, 100 GHz'''<br />
File: SkyMap143e.png | '''Full mission I, 143 GHz'''<br />
File: SkyMap217e.png | '''Full mission I, 217 GHz'''<br />
File: SkyMap353e.png | '''Full mission I, 353 GHz'''<br />
File: SkyMap545e.png | '''Full mission I, 545 GHz'''<br />
File: SkyMap857e.png | '''Full mission I, 857 GHz'''<br />
</gallery><br />
</center><br />
<br><br />
<center><br />
<gallery style="padding:0 0 0 0;" perrow=3 widths=260px heights=160px> <br />
File: LFI_SkyMap_030_1024_R2.01_full_Qb_sm1deg.png| '''Full mission Q, 30 GHz'''<br />
File: LFI_SkyMap_044_1024_R2.01_full_Qb_sm1deg.png | '''Full mission Q, 44 GHz'''<br />
File: LFI_SkyMap_070_1024_R2.01_full_Qb_sm1deg.png | '''Full mission Q, 70 GHz'''<br />
File: HFI_Skymap_100_full_bplcorrected_sm1deg_Qb.png | '''Full mission Q, 100 GHz'''<br />
File: HFI_Skymap_143_full_bplcorrected_sm1deg_Qb.png | '''Full mission Q, 143 GHz'''<br />
File: HFI_Skymap_217_full_bplcorrected_sm1deg_Qb.png | '''Full mission Q, 217 GHz'''<br />
File: HFI_Skymap_353_full_bplcorrected_sm1deg_Qb.png | '''Full mission Q, 353 GHz'''<br />
</gallery><br />
</center><br />
<br><br />
<center><br />
<gallery style="padding:0 0 0 0;" perrow=3 widths=260px heights=160px> <br />
File: LFI_SkyMap_030_1024_R2.01_full_Ub_sm1deg.png| '''Full mission U, 30 GHz'''<br />
File: LFI_SkyMap_044_1024_R2.01_full_Ub_sm1deg.png | '''Full mission U, 44 GHz'''<br />
File: LFI_SkyMap_070_1024_R2.01_full_Ub_sm1deg.png | '''Full mission U, 70 GHz'''<br />
File: HFI_Skymap_100_full_bplcorrected_sm1deg_Ub.png | '''Full mission U, 100 GHz'''<br />
File: HFI_Skymap_143_full_bplcorrected_sm1deg_Ub.png | '''Full mission U, 143 GHz'''<br />
File: HFI_Skymap_217_full_bplcorrected_sm1deg_Ub.png | '''Full mission U, 217 GHz'''<br />
File: HFI_Skymap_353_full_bplcorrected_sm1deg_Ub.png | '''Full mission U, 353 GHz'''<br />
</gallery><br />
<br />
</center><br />
<br />
''' Full mission light maps, full channel maps (6 HFI, 7 LFI) '''<br />
<br />
These maps are based on the Full mission maps but contain fewer columns, IQU from 30 to 353 GHz, and I only at 545 and 857 GHz. These maps have been produced to reduce the transfer time of the most downloaded frequency full mission maps.<br />
<br />
''' Nominal mission, full channel maps (6 HFI) '''<br />
<br />
These maps are similar to the ones above, but cover the nominal mission only. They are meant primarily to be compared to the PR1 products in order to see the level of improvements in the processing. Because of this, they are produced in Temperature only, and have not had the post-processing applied.<br />
<br />
''' Single survey, full channel maps (30 HFI, 35 LFI)'''<br />
<br />
Single survey maps are built using all valid detectors of a frequency channel; they cover separately the different sky surveys. The surveys are defined as the times over which the satellite spin axis rotates but 180 degrees, which, due to the position of the detectors in the focal plane does not cover the full sky, but a fraction between ~80 and 90% depending on detector position. During adjacent surveys the sky is scanned in opposite directions. More precisely it is the ecliptic equator that is scanned in opposite directions. While these are useful to investigate variable sources, they are also used to study the systematics of the time-response of the detectors as they scan bright sources, like the Galactic Plane, in different directions during different survey. Note that the HFI and LFI missions cover 5 and 8 surveys, respectively, and in case of HFI the last survey in incomplete.<br />
The 70 GHz surveys maps are available also at <math>N_{side}</math> 2048.<br />
Note LFI provide a special surveys maps combination used in the low l analysis. This maps, available at the three LFI frequency 30, 44 and 70 GHz, was built using the combination of survey 1, 3, 5, 6, 7 and 8. <br />
<br />
''' Year maps, full channel maps (12 HFI, 16 LFI)'''<br />
<br />
These maps are built using the data of surveys 1+2, surveys 3+4, and so forth. They are used to study long-term systematic effects.<br />
The 70 GHz years maps are available also at <math>N_{side}</math> 2048.<br />
<br />
'''Half-mission maps, full channel maps (12 HFI, 12 LFI)'''<br />
<br />
For HFI, the half mission is defined after eliminating those rings discarded for all bolometers. There are 347 such rings, may of which are during the 5th survey when the ''End-of-Life'' tests were performed. The remaining 26419 rings are divided in half (up to the odd ring) to define the two halves of the mission. This exercise is done for the full mission only.<br />
<br />
For LFI instead of the half-mission the following year combination has been created: Year 1+2, Year 1+3, Year 2+4, Year 3+4, <br />
<br />
'''Full mission, single detector maps (18 HFI, 22 LFI)'''<br />
<br />
IN case of HFI these maps are built only for the SWBs (non polarized) and contain only temperature data, of course. They are not built for the polarisation sensitive detectors because they are not fixed on the sky as the polarisation component depends on the position angle at the time of observation. Instead, we provide maps built by ''quads'' of polarisation-sensitive detectors (see next section), which have different polarisation angles and that can be used to built I, Q, and U maps<br />
<br />
{| border="1" cellpadding="3" cellspacing="0" align="center" style="text-align:left" width=600px<br />
|+ '''HFI Temperature sensitive bolometers'''<br />
|- bgcolor="ffdead" <br />
!Frequency || Detector names<br />
|-<br />
|143 GHz || 143-5, 6, 7<br />
|-<br />
|217 GHz || 217-1, 2, 3, 4<br />
|-<br />
|353 GHz || 353-1, 2, 7, 8<br />
|-<br />
|545 GHz || 545-1, 2, 4<br />
|-<br />
|857 GHz || 857-1, 2 , 3, 4<br />
|}<br />
<br />
The 143-8 and 353-3 bolometer data are affected by strong RTS (random telegraphic signal) noise. They have not been used in the data processing, and are not delivered. For a figure showing the focal plane layout, see [[Detector_pointing#Introduction_and_Summary | this Introduction]] of the Detector Pointing chapter.<br />
<br />
In case of LFI, all the 22 Radiometers maps are available, those, obviously, are only in temperature.<br />
<br />
'''Full mission, detector set or detector pairs maps (8 HFI, 8 LFI)'''<br />
<br />
The objective here is to build independent temperature (I) and polarisation (Q and U) maps with the two pairs of polarisation sensitive detectors of each channel where they are available, i.e. in the 44-353 GHz channels. The table below indicates which detectors were used to built each detector set (detset).<br />
<br />
<br />
{| border="1" cellpadding="3" cellspacing="0" align="center" style="text-align:left" width=600px<br />
|+ '''Definition of HFI Detector Sets'''<br />
|- bgcolor="ffdead" <br />
!Frequency || DetSet1 || DetSet2 <br />
|-<br />
|100 GHz || 100-1a/b & 100-4a/b || 100-2a/b & 100-3a/b<br />
|-<br />
|143 GHz || 143-1a/b 1 & 43-3a/b || 143-2a/b & 143-4a/b<br />
|-<br />
|217 GHz || 217-5a/b & 217-7a/b || 217-6a/b & 217-8a/b<br />
|-<br />
|353 GHz || 353-3a/b & 353-5a/b || 353-4a/b & 353-6a/b<br />
|}<br />
<br />
{| border="1" cellpadding="3" cellspacing="0" align="center" style="text-align:left" width=600px<br />
|+ '''Definition of LFI Detector Pairs'''<br />
|- bgcolor="ffdead" <br />
!Frequency || Horn Pair || Comment <br />
|-<br />
|44 GHz || 24 || This maps is only in temperature<br />
|-<br />
|44 GHz || 25 & 26 || <br />
|-<br />
|70 GHz || 18 & 23 || Available also at <math>N_{side}</math> = 2048<br />
|-<br />
|70 GHz || 19 & 22 || Available also at <math>N_{side}</math> = 2048<br />
|-<br />
|70 GHz || 20 & 21 || Available also at <math>N_{side}</math> = 2048<br />
|}<br />
<br />
<br />
'''Half-ring maps (64 HFI, 62 LFI)'''<br />
<br />
These maps are similar to the ones above, but are built using only the first or the second half of each ring (or pointing period). The HFI provides half-ring maps for the full mission only, and for the full channel, the detsets, and the single bolometers. The LFI provides half-rings maps for the channel full mission (70 GHz also at <math>N_{side}</math> 2048), for the radiometer full mission and the horn pairs full mission.<br />
<!----<br />
'''Masks'''<br />
<br />
Masks are provided of the Galactic Plane and of the point sources. For the Galactic Plane, eight masks are given covering different fractions of the sky, and for the points sources two masks are given, at the 5 and 10 sigma level, for each Planck HFI and LFI frequency channel. These are generic masks, specific masks applicable to other products are delivered with the products themselves.<br />
---><br />
<br />
''' The Zodiacal light correction maps '''<br />
<br />
The Zodiacal light signal depends on the location of the observer relative to the Zodiacal light bands, and thus it is not a fixed pattern on the sky but depends on the period of observation. The maps presented here are the difference between the uncorrected (and not delivered) and the corrected maps. <br />
<br />
Note that while the Zodiacal light model that is subtracted at ring level (see [[Map-making#Zodiacal_light_correction | here]]) is not polarised, the corrections are not null and Q and U. This is suspected to come from some combination of leakage due to bandpass differences and beam mismatch, and maybe other effects. These leakages are typically of order a few %, at max, of the maximum zodi intensity at I for each channel. They range from ~150 nK at 100 GHz to ~5 uK at 353 GHz.<br />
<br />
''' Caveats and known issues '''<br />
<br />
; HFI polarization 100-217 GHz : at low multipoles, despite the progress that has been made to control the systematic effects present in the maps, polarization data between 100-217 GHz are still contaminated by systematic residuals. Figure 10 of {{PlanckPapers|planck2014-a09}} shows the EE power spectra from the half-difference maps at 100, 143, and 217 GHz and compared to the noise power spectrum from FFP8 simulations. he half-ring differences are compatible with noise while, at multipoles typically lower than 50, detector-set and half-mission differences are dominated by excess power which is larger than the EE CMB signal. The Planck Collaboration has used the range ell>30 to carry out component separation ({{PlanckPapers|planck2014-a11}}), as data at ell<30 is not considered usable for cosmological analyses. The origin of the excess power will be explored in a forthcoming publication.<br />
<br />
<br />
'''Inputs'''<br />
''' HFI inputs '''<br />
<br />
The HFI mapmaking takes as input:<br />
* the cleaned TOIs of signal of each detector, together with their flags, produced by the [[TOI processing|TOI processing]] pipeline;<br />
* the TOIs of pointing (quaternions), described in [[Detector_pointing|Detector pointing]];<br />
* bolometer-level characterization data, from the DPC's internal IMO (not distributed);<br />
* Planck orbit data, used to compute and remove the Earth's dipole;<br />
* Planck solar dipole information, used to calibrate the CMB channels;<br />
* Planet models used to calibrate the Galactic channels.<br />
<br />
''' LFI inputs '''<br />
<br />
The Madam mapmaker takes as input:<br />
<br />
* the calibrated timelines (for details see [[TOI processing LFI|TOI Processing]]);<br />
* the detector pointings (for details see [[Detector_pointing|Detector pointing]]);<br />
* the noise information in the form of 3-parameter (white noise level, &sigma;, slope, and knee frequency, <i>f</i><sub>knee</sub>) noise model (for details see [[The RIMO|RIMO]])<br />
<br />
'''Related products'''<br />
''' Masks '''<br />
<br />
This section presents the masks of the point sources and of the Galactic plane. These are ''general purpose'' masks. Other masks specific to certain products are packaged with the products.<br />
<br />
'''Point source masks'''<br />
<br />
For HFI and LFI two sets of masks are provided: <br />
* Intensity masks, which removes sources detected with SNR > 5. <br />
* Polarisation masks, which remove sources which have polarisation detection significance of 99.97 % or greater at the position of a source detected in intensity. They were derived from the polarisation maps with dust ground bandpass mismatch leakage correction applied. The cut around each source has a radius of 3σ (width) of the beam ~ 1.27 FWHM (for LFI the cut around each source has a radius of 32 arcmin at 30GHz, 27 arcmin at 44 GHz and 13 arcmin at 70 GHz).<br />
<br />
Both sets are found in the files ''HFI_Mask_PointSrc_2048_R2.00.fits'' and ''LFI_Mask_PointSrc_2048_R2.00.fits'' in which the first extension contains the Intensity masks, and the second contains the Polarisation masks.<br />
<br />
'''Galactic plane masks'''<br />
<br />
Eight masks are provided giving 20, 40, 60, 70, 80, 90, 97, and 99% sky coverage derived from the 353 GHz map, after CMB subtraction. They are independent of frequency channel. Three versions of these are given: not apodized, and apodized by 2 and 5 deg. The filenames are ''HFI_Mask_GalPlane-apoN_2048_R2.00.fits'', where N = 0, 2, 5.<br />
<br />
The masks are shows below. The 8 GalPlane masks are combined (added together) and shown in a single figure for each of the three apodization. While the result is quite clear for the case of no apodization, it is less so for the apodized case. The point source masks are shown separately for the Intensity case.<br />
<br />
<center><br />
<gallery perrow=3 widths=260px heights=160px ><br />
File: GalPlaneMask_apo0.png | '''Galactic Plane masks, no apod'''<br />
File: GalPlaneMask_apo2.png | '''Galactic Plane masks, apod 2 deg'''<br />
File: GalPlaneMask_apo5.png | '''Galactic Plane masks, apod 5 deg'''<br />
File: PointSrcMask_100.png | '''PointSource mask 100 GHz'''<br />
File: PointSrcMask_143.png | '''PointSource mask 143 GHz'''<br />
File: PointSrcMask_217.png | '''PointSource mask 217 GHz'''<br />
File: PointSrcMask_353.png | '''PointSource mask 343 GHz'''<br />
File: PointSrcMask_545.png | '''PointSource mask 545 GHz'''<br />
File: PointSrcMask_857.png | '''PointSource mask 857 GHz'''<br />
</gallery><br />
</center><br />
<br />
''' File names '''<br />
The FITS filenames are of the form ''{H|L}FI_SkyMap_fff{-tag}_Nside_R2.nn_{coverage}-{type}.fits'', where ''fff'' are three digits to indicate the Planck frequency band, ''tag'' indicates the single detector or the detset, ''Nside'' is the Healpix Nside of the map, ''coverage'' indicates which part of the mission is covered (full, half mission, survey, year, ...) , and the optional ''type'' indicates the subset of input data used. The table below lists the products by type, with the appropriate unix wildcards that form the full filename.<br />
<br />
{| class="wikitable" align="center" style="text-align"left" border="1" cellpadding="15" cellspacing="20" width=880px<br />
|+ '''HFI FITS filenames'''<br />
|- bgcolor="ffdead"<br />
! Coverage || filename || half-ring filename <br />
|-<br />
| Full chan, full mission ||HFI_SkyMap_???_2048_R2.??_full.fits ||HFI_SkyMap_???_2048_R2.??_full-ringhalf-?.fits<br />
|-<br />
| Full channel, nominal mission ||HFI_SkyMap_???_2048_R2.??_nominal.fits || n/a<br />
|-<br />
| Full channel, single survey || HFI_SkyMap_???_2048_R2.??_survey-?.fits || n/a<br />
|-<br />
| Full channel, single year || HFI_SkyMap_???_2048_R2.??_year-?.fits || n/a<br />
|-<br />
| Full channel, half mission || HFI_SkyMap_???_2048_R2.??_halfmission*-?.fits || n/a<br />
|-<br />
| Det-set, full mission || HFI_SkyMap_???-ds?_2048_R2.??_full.fits || HFI_SkyMap_???-ds?_2048_R2.??_full-ringhalf-?.fits<br />
|-<br />
|Single SWB, full mission || HFI_SkyMap_???-?_2048_R2.??_full.fits || HFI_SkyMap_???-?_2048_R2.??_full-ringhalf-?.fits<br />
|}<br />
<br />
{| class="wikitable" align="center" style="text-align"left" border="1" cellpadding="15" cellspacing="20" width=1000px<br />
|+ '''LFI FITS filenames'''<br />
|- bgcolor="ffdead"<br />
! Coverage || filename || half-ring filename || Comment<br />
|-<br />
| Full channel, full mission ||LFI_SkyMap_???_1024_R2.??_full.fits ||LFI_SkyMap_???_1024_R2.??_full-ringhalf-?.fits || Available also at Nside = 2048<br />
|-<br />
| Full channel, single survey || LFI_SkyMap_???_1024_R2.??_survey-?.fits || n/a || Available also at Nside = 2048<br />
|-<br />
| Full channel, survey combination || LFI_SkyMap_???_1024_R2.??_survey-1-3-5-6-7-8.fits || n/a || n/a<br />
|-<br />
| Full channel, single year || LFI_SkyMap_???_1024_R2.??_year-?.fits || n/a || Available also at Nside = 2048<br />
|-<br />
| Full channel, year combination || LFI_SkyMap_???_1024_R2.??_year?-?.fits || n/a || n/a<br />
|-<br />
| Horn pair, full mission || LFI_SkyMap_???-??-??_1024_R2.??_full.fits || LFI_SkyMap_???_??-??_1024_R2.??_full-ringhalf-?.fits || Available also at Nside = 2048<br />
|-<br />
| Single radiometer, full mission || LFI_SkyMap_???-???_1024_R2.??_full.fits || LFI_SkyMap_???-???_1024_R2.??_full-ringhalf-?.fits || n/a<br />
|}<br />
<br />
<br />
<br />
For the benefit of users who are only looking for the frequency maps with no additional information, we also provide a file combining the 9 frequency maps as separate columns in a single extension. The 9 columns in this file contain the intensity maps ONLY and no other information (hit maps and variance maps) is provided.<br />
<br />
<!---<br />
{| class="wikitable" align="center" style="text-align:center" border="1" cellpadding="3" cellspacing="0" width=500px<br />
|+ '''FITS filenames'''<br />
|- bgcolor="ffdead"<br />
! Frequency || Full channel maps<br />
|-<br />
| '''30GHz''' || {{PLASingleFile|fileType=map|name=LFI_SkyMap_030_1024_R1.10_nominal.fits|link=LFI_SkyMap_030_1024_R1.10_nominal.fits}}<br />
|-<br />
| '''44GHz''' || {{PLASingleFile|fileType=map|name=LFI_SkyMap_044_1024_R1.10_nominal.fits|link=LFI_SkyMap_044_1024_R1.10_nominal.fits}}<br />
|-<br />
| '''70GHz''' || {{PLASingleFile|fileType=map|name=LFI_SkyMap_070_1024_R1.10_nominal.fits|link=LFI_SkyMap_070_1024_R1.10_nominal.fits}}<br />
|-<br />
| '''70GHz''' || {{PLASingleFile|fileType=map|name=LFI_SkyMap_070_2048_R1.10_nominal.fits|link=LFI_SkyMap_070_2048_R1.10_nominal.fits}}<br />
|-<br />
| '''100GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_100_2048_R1.10_nominal.fits|link=HFI_SkyMap_100_2048_R1.10_nominal.fits}}<br />
|-<br />
| '''143GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_143_2048_R1.10_nominal.fits|link=HFI_SkyMap_143_2048_R1.10_nominal.fits}}<br />
|-<br />
| '''217GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_217_2048_R1.10_nominal.fits|link=HFI_SkyMap_217_2048_R1.10_nominal.fits}}<br />
|-<br />
| '''353GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_353_2048_R1.10_nominal.fits|link=HFI_SkyMap_353_2048_R1.10_nominal.fits}}<br />
|-<br />
| '''545GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_545_2048_R1.10_nominal.fits|link=HFI_SkyMap_545_2048_R1.10_nominal.fits}}<br />
|-<br />
| '''857GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_857_2048_R1.10_nominal.fits|link=HFI_SkyMap_857_2048_R1.10_nominal.fits}}<br />
|- bgcolor="ffdead"<br />
! Frequency || Full channel, Zodi-corrected maps<br />
|-<br />
| '''100GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_100_2048_R1.10_nominal_ZodiCorrected.fits|link=HFI_SkyMap_100_2048_R1.10_nominal_ZodiCorrected.fits}} <br />
|-<br />
| '''143GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_143_2048_R1.10_nominal_ZodiCorrected.fits|link=HFI_SkyMap_143_2048_R1.10_nominal_ZodiCorrected.fits}}<br />
|-<br />
| '''217GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_217_2048_R1.10_nominal_ZodiCorrected.fits|link=HFI_SkyMap_217_2048_R1.10_nominal_ZodiCorrected.fits}}<br />
|-<br />
| '''353GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_353_2048_R1.10_nominal_ZodiCorrected.fits|link=HFI_SkyMap_353_2048_R1.10_nominal_ZodiCorrected.fits}}<br />
|-<br />
| '''545GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_545_2048_R1.10_nominal_ZodiCorrected.fits|link=HFI_SkyMap_545_2048_R1.10_nominal_ZodiCorrected.fits}}<br />
|-<br />
| '''857GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_857_2048_R1.10_nominal_ZodiCorrected.fits|link=HFI_SkyMap_857_2048_R1.10_nominal_ZodiCorrected.fits}}<br />
|- bgcolor="ffdead"<br />
! Frequency || Combined frequency maps<br />
|-<br />
| '''All''' || {{PLASingleFile|fileType=file|name=COM_MapSet_I-allFreqs_R1.10_nominal.fits|link=COM_MapSet_I-allFreqs_R1.10_nominal.fits}} <br />
|}<br />
<br />
<br />
{| class="wikitable" align="center" style="text-align:center" border="1" cellpadding="3" cellspacing="0" width=850px<br />
|+ '''FITS filenames'''<br />
|- bgcolor="ffdead"<br />
! Frequency || Survey 1 maps || Survey 2 maps<br />
|-<br />
| '''30GHz''' || {{PLASingleFile|fileType=map|name=LFI_SkyMap_030_1024_R1.10_survey_1.fits|link=LFI_SkyMap_030_1024_R1.10_survey_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=LFI_SkyMap_030_1024_R1.10_survey_2.fits|link=LFI_SkyMap_030_1024_R1.10_survey_2.fits}}<br />
|-<br />
| '''44GHz''' || {{PLASingleFile|fileType=map|name=LFI_SkyMap_044_1024_R1.10_survey_1.fits|link=LFI_SkyMap_044_1024_R1.10_survey_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=LFI_SkyMap_044_1024_R1.10_survey_2.fits|link=LFI_SkyMap_044_1024_R1.10_survey_2.fits}}<br />
|-<br />
| '''70GHz''' || {{PLASingleFile|fileType=map|name=LFI_SkyMap_070_1024_R1.10_survey_1.fits|link=LFI_SkyMap_070_1024_R1.10_survey_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=LFI_SkyMap_070_1024_R1.10_survey_2.fits|link=LFI_SkyMap_070_1024_R1.10_survey_2.fits}}<br />
|-<br />
| '''70GHz''' || {{PLASingleFile|fileType=map|name=LFI_SkyMap_070_2048_R1.10_survey_1.fits|link=LFI_SkyMap_070_2048_R1.10_survey_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=LFI_SkyMap_070_2048_R1.10_survey_2.fits|link=LFI_SkyMap_070_2048_R1.10_survey_2.fits}}<br />
|-<br />
| '''100GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_100_2048_R1.10_survey_1.fits|link=HFI_SkyMap_100_2048_R1.10_survey_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_100_2048_R1.10_survey_2.fits|link=HFI_SkyMap_100_2048_R1.10_survey_2.fits}}<br />
|-<br />
| '''143GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_143_2048_R1.10_survey_1.fits|link=HFI_SkyMap_143_2048_R1.10_survey_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_143_2048_R1.10_survey_2.fits|link=HFI_SkyMap_143_2048_R1.10_survey_2.fits}}<br />
|-<br />
| '''217GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_217_2048_R1.10_survey_1.fits|link=HFI_SkyMap_217_2048_R1.10_survey_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_217_2048_R1.10_survey_2.fits|link=HFI_SkyMap_217_2048_R1.10_survey_2.fits}}<br />
|-<br />
| '''353GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_353_2048_R1.10_survey_1.fits|link=HFI_SkyMap_353_2048_R1.10_survey_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_353_2048_R1.10_survey_2.fits|link=HFI_SkyMap_353_2048_R1.10_survey_2.fits}}<br />
|-<br />
| '''545GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_545_2048_R1.10_survey_1.fits|link=HFI_SkyMap_545_2048_R1.10_survey_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_545_2048_R1.10_survey_2.fits|link=HFI_SkyMap_545_2048_R1.10_survey_2.fits}}<br />
|-<br />
| '''857GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_857_2048_R1.10_survey_1.fits|link=HFI_SkyMap_857_2048_R1.10_survey_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_857_2048_R1.10_survey_2.fits|link=HFI_SkyMap_857_2048_R1.10_survey_2.fits}}<br />
|- bgcolor="ffdead"<br />
! Frequency || Survey 1 Zodi-corrected maps || Survey 2 Zodi-corrected maps<br />
|-<br />
| '''100GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_100_2048_R1.10_survey_1_ZodiCorrected.fits|link=HFI_SkyMap_100_2048_R1.10_survey_1_ZodiCorrected.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_100_2048_R1.10_survey_2_ZodiCorrected.fits|link=HFI_SkyMap_100_2048_R1.10_survey_2_ZodiCorrected.fits}}<br />
|-<br />
| '''143GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_143_2048_R1.10_survey_1_ZodiCorrected.fits|link=HFI_SkyMap_143_2048_R1.10_survey_1_ZodiCorrected.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_143_2048_R1.10_survey_2_ZodiCorrected.fits|link=HFI_SkyMap_143_2048_R1.10_survey_2_ZodiCorrected.fits}}<br />
|-<br />
| '''217GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_217_2048_R1.10_survey_1_ZodiCorrected.fits|link=HFI_SkyMap_217_2048_R1.10_survey_1_ZodiCorrected.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_217_2048_R1.10_survey_2_ZodiCorrected.fits|link=HFI_SkyMap_217_2048_R1.10_survey_2_ZodiCorrected.fits}}<br />
|-<br />
| '''353GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_353_2048_R1.10_survey_1_ZodiCorrected.fits|link=HFI_SkyMap_353_2048_R1.10_survey_1_ZodiCorrected.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_353_2048_R1.10_survey_2_ZodiCorrected.fits|link=HFI_SkyMap_353_2048_R1.10_survey_2_ZodiCorrected.fits}}<br />
|-<br />
| '''545GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_545_2048_R1.10_survey_1_ZodiCorrected.fits|link=HFI_SkyMap_545_2048_R1.10_survey_1_ZodiCorrected.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_545_2048_R1.10_survey_2_ZodiCorrected.fits|link=HFI_SkyMap_545_2048_R1.10_survey_2_ZodiCorrected.fits}}<br />
|-<br />
| '''857GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_857_2048_R1.10_survey_1_ZodiCorrected.fits|link=HFI_SkyMap_857_2048_R1.10_survey_1_ZodiCorrected.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_857_2048_R1.10_survey_2_ZodiCorrected.fits|link=HFI_SkyMap_857_2048_R1.10_survey_2_ZodiCorrected.fits}}<br />
|- bgcolor="ffdead"<br />
! Frequency || Half-ring 1 maps ||Half-ring 2 maps<br />
|-<br />
| '''30GHz''' || {{PLASingleFile|fileType=map|name=LFI_SkyMap_030_1024_R1.10_nominal_ringhalf_1.fits|link=LFI_SkyMap_030_1024_R1.10_nominal_ringhalf_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=LFI_SkyMap_030_1024_R1.10_nominal_ringhalf_2.fits|link=LFI_SkyMap_030_1024_R1.10_nominal_ringhalf_2.fits}}<br />
|-<br />
| '''44GHz''' || {{PLASingleFile|fileType=map|name=LFI_SkyMap_044_1024_R1.10_nominal_ringhalf_1.fits|link=LFI_SkyMap_044_1024_R1.10_nominal_ringhalf_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=LFI_SkyMap_044_1024_R1.10_nominal_ringhalf_2.fits|link=LFI_SkyMap_044_1024_R1.10_nominal_ringhalf_2.fits}}<br />
|-<br />
| '''70GHz''' || {{PLASingleFile|fileType=map|name=LFI_SkyMap_070_1024_R1.10_nominal_ringhalf_1.fits|link=LFI_SkyMap_070_1024_R1.10_nominal_ringhalf_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=LFI_SkyMap_070_1024_R1.10_nominal_ringhalf_2.fits|link=LFI_SkyMap_070_1024_R1.10_nominal_ringhalf_2.fits}}<br />
|-<br />
| '''70GHz''' || {{PLASingleFile|fileType=map|name=LFI_SkyMap_070_2048_R1.10_nominal_ringhalf_1.fits|link=LFI_SkyMap_070_2048_R1.10_nominal_ringhalf_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=LFI_SkyMap_070_2048_R1.10_nominal_ringhalf_2.fits|link=LFI_SkyMap_070_2048_R1.10_nominal_ringhalf_2.fits}}<br />
|-<br />
| '''100GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_100_2048_R1.10_nominal_ringhalf_1.fits|link=HFI_SkyMap_100_2048_R1.10_nominal_ringhalf_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_100_2048_R1.10_nominal_ringhalf_2.fits|link=HFI_SkyMap_100_2048_R1.10_nominal_ringhalf_2.fits}}<br />
|-<br />
| '''143GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_143_2048_R1.10_nominal_ringhalf_1.fits|link=HFI_SkyMap_143_2048_R1.10_nominal_ringhalf_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_143_2048_R1.10_nominal_ringhalf_2.fits|link=HFI_SkyMap_143_2048_R1.10_nominal_ringhalf_2.fits}}<br />
|-<br />
| '''217GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_217_2048_R1.10_nominal_ringhalf_1.fits|link=HFI_SkyMap_217_2048_R1.10_nominal_ringhalf_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_217_2048_R1.10_nominal_ringhalf_2.fits|link=HFI_SkyMap_217_2048_R1.10_nominal_ringhalf_2.fits}}<br />
|-<br />
| '''353GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_353_2048_R1.10_nominal_ringhalf_1.fits|link=HFI_SkyMap_353_2048_R1.10_nominal_ringhalf_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_353_2048_R1.10_nominal_ringhalf_2.fits|link=HFI_SkyMap_353_2048_R1.10_nominal_ringhalf_2.fits}}<br />
|-<br />
| '''545GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_545_2048_R1.10_nominal_ringhalf_1.fits|link=HFI_SkyMap_545_2048_R1.10_nominal_ringhalf_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_545_2048_R1.10_nominal_ringhalf_2.fits|link=HFI_SkyMap_545_2048_R1.10_nominal_ringhalf_2.fits}}<br />
|-<br />
| '''857GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_857_2048_R1.10_nominal_ringhalf_1.fits|link=HFI_SkyMap_857_2048_R1.10_nominal_ringhalf_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_857_2048_R1.10_nominal_ringhalf_2.fits|link=HFI_SkyMap_857_2048_R1.10_nominal_ringhalf_2.fits}}<br />
|}<br />
---><br />
<br />
''' FITS file structure '''<br />
<br />
The FITS files for the sky maps contain a minimal primary header with no data, and a ''BINTABLE'' extension (EXTENSION 1, EXTNAME = ''FREQ-MAP'') containing the data. The structure is shows schematically in the figure below. The ''FREQ-MAP'' extension contains a 3- or a 10-column table that contain the signal, hit-count and variance maps, all in Healpix format. The 3-column case is for intensity only maps, the 10-column case is for polarisation. The number of rows is the number of map pixels, which is Npix = 12 <math>N_{side}</math><sup>2</sup> for Healpix maps, where <math>N_{side}</math> = 1024 or 2048 for most the maps presented in this chapter.<br />
<br />
[[File:FITS_FreqMap.png | 550px | center | thumb | '''FITS file structure''']]<br />
<br />
Note that file sizes are ~0.6 GB for I-only maps and ~1.9 GB for I,Q,U maps at <math>N_{side}</math> 2048 and ~0.14 GB for I-only maps and ~0.45 GB for I,Q,U maps at <math>N_{side}</math> 1024 .<br />
<br />
Keywords indicate the coordinate system (GALACTIC), the Healpix ordering scheme (NESTED), the units (K_cmb or MJy/sr) of each column, and of course the frequency channel (FREQ). Where polarisation Q and U maps are provided, the ''COSMO'' polarisation convention (used in HEALPIX) is adopted, and it is specified in the ''POLCCONV'' keyword (see [[Sky_temperature_maps#Polarization_convention_used_in_the_Planck_project|this section]]. The COMMENT fields give a one-line summary of the product, and some other information useful for traceability within the DPCs. The original filename is also given in the ''FILENAME'' keyword. The ''BAD_DATA'' keyword gives the value used by Healpix to indicate pixels for which no signal is present (these will also have a hit-count value of 0). The main parameters are summarised below:<br />
<br />
<br />
{| border="1" cellpadding="3" cellspacing="0" align="center" style="text-align:left" width=800px<br />
|+ '''Sky map file data structure'''<br />
|- bgcolor="ffdead" <br />
!colspan="4" | 1. EXTNAME = 'FREQ-MAP' : Data columns<br />
|- bgcolor="ffdead" <br />
! Column Name || Data Type || Units || Description<br />
|-<br />
|I_STOKES || Real*4 || K_cmb or MJy/sr || The Stokes I map<br />
|-<br />
|Q_STOKES || Real*4 || K_cmb or MJy/sr || The Stokes Q map (optional)<br />
|-<br />
|U_STOKES || Real*4 || K_cmb or MJy/sr || The Stokes U map (optional)<br />
|-<br />
|HITS || Int*4 || none || The hit-count map<br />
|-<br />
|II_COV || Real*4 || K_cmb<sup>2</sup> or (MJy/sr)<sup>2</sup> || The II variance map<br />
|-<br />
|IQ_COV || Real*4 || K_cmb<sup>2</sup> or (MJy/sr)<sup>2</sup> || The IQ variance map (optional)<br />
|-<br />
|IU_COV || Real*4 || K_cmb<sup>2</sup> or (MJy/sr)<sup>2</sup> || The IQ variance map (optional)<br />
|-<br />
|QQ_COV || Real*4 || K_cmb<sup>2</sup> or (MJy/sr)<sup>2</sup> || The QQ variance map (optional)<br />
|-<br />
|QU_COV || Real*4 || K_cmb<sup>2</sup> or (MJy/sr)<sup>2</sup> || The QU variance map (optional)<br />
|-<br />
|UU_COV || Real*4 || K_cmb<sup>2</sup> or (MJy/sr)<sup>2</sup> || The UU variance map (optional)<br />
|-<br />
|- bgcolor="ffdead" <br />
! Keyword || Data Type || Value || Description<br />
|-<br />
|PIXTYPE || string || HEALPIX ||<br />
|-<br />
|COORDSYS || string || GALACTIC ||Coordinate system <br />
|-<br />
|ORDERING || string || NESTED || Healpix ordering<br />
|-<br />
|POLCCONV || String || COSMO || Polarization convention<br />
|-<br />
|NSIDE || Int || 1024 or 2048 || Healpix <math>N_{side}</math> <br />
|-<br />
|FIRSTPIX || Int*4 || 0 || First pixel number<br />
|-<br />
|LASTPIX || Int*4 || 12 <math>N_{side}</math><sup>2</sup> – 1 || Last pixel number<br />
|-<br />
|FREQ || string || nnn || The frequency channel <br />
|}<br />
<br />
<br />
The same structure applies to all ''SkyMap'' products, independent of whether they are full channel, survey of half-ring. The distinction between the types of maps is present in the FITS filename (and in the traceability comment fields).<br />
<br />
'''Polarization convention used in the Planck project'''<br />
<br />
The Planck collaboration used the COSMO convention for the polarization angle (as usually used in space based CMB missions), whereas other astronomical fields usually use the IAU convention. In the following document we report the difference between these two conventions, and the consequence if it is NOT taken into account correctly in the analysis.<br />
<br />
[[File:conventions.png|thumb|center|400px|'''Figure 1. COSMO convention (left) and IAU convention (right). The versor <math>\hat{z}</math> points outwards the pointing direction in COSMO, and inwards in IAU. The bottom panel refers to the plane tangent to the sphere.''']]<br />
<br />
Changing the orientation convention is equivalent to a transformation <math>\psi'=\pi-\psi</math> of the polarization angle (Figure 1). The consequence of this transformation is the inversion of the Stokes parameter <math>U</math>.<br />
The components of the polarization tensor in the helicity basis <math>\epsilon^{\pm}=1/\sqrt{2}(\hat{x}\pm i\hat{y})</math> are:<br />
<br />
<math><br />
(Q+iU)(\hat{n}) = \sum _{\ell m}a_{2,lm}{}_{2}Y_{\ell }^{m}(\hat{n})<br />
\\(Q-iU)(\hat{n}) = \sum _{\ell m}a_{-2,lm}{}_{2}Y_{\ell }^{m}(\hat{n})<br />
</math><br />
<br />
where <math>{}_{2}Y_{\ell }^{m}(\hat{n})</math> are the spin weighted spherical harmonic functions.<br />
The <math>E</math> and <math>B</math> modes can be defined as:<br />
<math><br />
E(\hat{n}) = \sum_{\ell m}a_{E,\ell m}Y_{\ell }^{m}(\hat{n})<br />
\\B(\hat{n}) = \sum_{\ell m}a_{B,\ell m}Y_{\ell }^{m}(\hat{n})<br />
</math><br />
<br />
where the coefficients <math>a_{E,\ell m}</math> and <math>a_{B,\ell m}</math> are derived from linear combinations of the <math>a_{2,\ell m}</math> , <math>a_{-2,\ell m}</math> defined implicitly in the first equation (<math>Q\pm iU</math>).<br />
<br />
[[File:test_gradient.jpg|thumb|center|400px|]]<br />
[[File:test_curl.jpg|thumb|center|400px|'''Figure 2. Error on Planck-LFI 70 GHz <math>EE</math> (top) and <math>BB</math> (bottom) spectra, in case of wrong choice of the coordinate system convention (IAU instead of COSMO).''']]<br />
<br />
The effect of the sign inversion of <math>U</math> on the polarization spectra is a non trivial mixing of <math>E</math> and <math>B</math> modes. <br />
<br />
An example of the typical error on <math>EE</math> and <math>BB</math> auto-spectra in case of a wrong choice of the polarization basis is shown in Figure 2.<br />
<br />
BE CAREFUL about the polarization convention you are using. If the IAU convention is used in computing the power spectra, the sign of the <math>U</math> component of the Planck maps must be inverted before computing <math>E</math> and <math>B</math> modes.<br />
<br />
''' Note on the convention used by the Planck Catalogue of Compact Sources (PCCS) '''<br />
For continuity with other compact sources catolgues, the Catalogue of Compact Sources provided by Planck follows the IAU convention, and the polarization angles are defined on an interval of [-90&deg;,90&deg;]. To switch to the COSMO convention, the polarization angles listed in the catalogue have to be shifted by 90&deg; and multiplied by -1.<br />
<br />
== References ==<br />
<References /><br />
<br />
</div><br />
</div><br />
<br />
<div class="toccolours mw-collapsible mw-collapsed" style="background-color: #EEE8AA;width:80%" ><br />
'''2013 Sky temperature maps'''<br />
<br />
<div class="mw-collapsible-content"><br />
<br />
'''General description'''<br />
<br />
<br />
Sky maps give the best estimate of the intensity of the signal from the sky after removal, as far as possible, of known systematic effects and of the dipole signals induced by the motion of the solar system in the CMB and of the Planck satellite in the solar system. Sky maps are provided for the nominal Planck mission and also, separately, for the first two single surveys, the third one being covered only for a small part during the nominal mission.The details of the start and end times of each are given in [[HFIpreprocessingstatics | this table]]. As a secondary product, maps with estimates of the Zodiacal light and Far-Side-Lobes contribution removed are also provided. <br />
<br />
For characterization purposes, are also provided maps covering the nominal survey but each one using only half of the available data. These are the ''ringhalf_{1|2}'' maps, which are built using the first and second half of the stable pointing part in each pointing period. These maps are used extensively to investigate the (high frequency) noise properties the maps themselves and of other products described elsewhere (see e.g., the [[HFI-Validation | data validation]] section).<br />
<br />
To help in further processing, there are also masks of the Galactic Plane and of point sources, each provided for several different depths.<br />
<br />
All sky maps are in Healpix format, with Nside of 2048 for HFI and of 1024 for LFI (note that the LFI 70 GHz has been delivered also at Nside of 2048 to be directly comparable with HFI maps), in Galactic coordinates, and Nested ordering. The signal is given in units of K<sub>cmb</sub> for 30-353 GHz, and of MJy/sr (for a constant $\nu F_\nu$ energy distribution ) for 545 and 857 GHz. Each sky map is packaged into a ''BINTABLE'' extension of a FITS file together with a hit-count map (or hit map, for short, giving the number of observation samples that are cumulated in a pixel, all detectors combined) and a variance map (determined from the half-ring maps), and additional information is given in the FITS file header. The structure of the FITS file is given in the [[#Format | FITS file structure]] section below.<br />
<br />
<br />
'''Types of maps '''<br />
<br />
; Full channel maps<br />
: Full channel maps are built using all the valid detectors of a frequency channel and cover the nominal mission. For HFI, the 143-8 and 545-3 bolometers are rejected entirely as they are seriously affected by RTS noise. The maps are displayed in the figures below. The range is the same from 30 - 143 GHz in order to show the CMB at the same level. At higher frequencies the range is increased in order to keep the Galactic Plane from invading the whole sky.<br />
<br />
<center><br />
<gallery style="padding:0 0 0 0;" perrow=3 widths=260px heights=160px> <br />
File: SkyMap30.png| '''Nominal mission, 30 GHz'''<br />
File: SkyMap44.png | '''Nominal mission, 44 GHz'''<br />
File: SkyMap70.png | '''Nominal mission, 70 GHz'''<br />
File: SkyMap100.png | '''Nominal mission, 100 GHz'''<br />
File: SkyMap143.png | '''Nominal mission, 143 GHz'''<br />
File: SkyMap217.png | '''Nominal mission, 217 GHz'''<br />
File: SkyMap353.png | '''Nominal mission, 353 GHz'''<br />
File: SkyMap545.png | '''Nominal mission, 545 GHz'''<br />
File: SkyMap857.png | '''Nominal mission, 857 GHz'''<br />
</gallery><br />
</center><br />
<br />
; Single survey maps <br />
: Single survey maps are built using all valid detectors of a frequency channel; they cover separately the different sky surveys. The surveys are defined as the times over which the satellite spin axis rotates but 180 degrees, which, due to the position of the detectors in the focal plane does not cover the full sky, but a fraction between ~80 and 90% depending on detector position.<br />
<br />
; Detector set or detector pairs maps<br />
: These are maps built from a subset of the detectors in a frequency channel, typically our of two PSB pairs (i.e., four poloarisation-sensitive bolometers with different orientation on the sky), for HFI in order to extract a single temperature map. While none of these maps are part of the first Planck data release, the concept of ''detset'' is used, and thus it is worth mentioning it here. In particular, information by detector set is available at the [[Frequency_maps_angular_power_spectra | sky power spectrum]] level and in the [[The RIMO | RIMO]].<br />
<br />
; Half-ring maps<br />
: Half-ring maps are built using only the first or the second half of the stable pointing period data. There are thus two half-ring maps per frequency channel named ''ringhalf_1'' and ''ringhalf_2'' respectively. These maps are built for characterization purposes in order to perform null tests. In particular, the difference between the two half-ring maps at a given frequency give a good estimate of the high frequency noise in the data (albeit biased low by ~0.5% for the HFI channels due to specifics of the TOI processing).<br />
<br />
; Masks<br />
: Masks are provided of the Galactic Plane and of the point sources. For the Galactic Plane, eight masks are given covering different fractions of the sky, and for the points sources two masks are given, at the 5 and 10 sigma level, for each Planck HFI frequency channel. These are generic masks, specific masks applicable to other products are delivered with the products themselves.<br />
<br />
''' Caveats and known issues'''<br />
<br />
The primary limitation of the HFI maps are<br />
* the absence of correction of the ADC non-linearities,<br />
* the far-side lobe contribution is not accounted for in the processing and in the calibration,<br />
* the dipole removal is based on the non-relativistic approximation which leaves a weak quadrupole component in the map.<br />
And thus the overall calibration accuracy is at the 0.2% level in 100-217 GHz channels<br />
<br />
The LFI 70 GHz maps at Nside=2048 should be considered as additional product, the default are the LFI maps at Nside=1024. No effective beam at Nside=2048 is provided, only at Nside=1024, for this reason the use of the effective beam with maps at Nside 2048 is discouraged.<br />
<br />
''' Map zero-level '''<br />
<br />
For the 100 to 857 GHz maps, the zero levels are set to their optimal levels for Galactic and CIB studies. A procedure for adjusting them to astrophysical values is given in the HFI Calibration paper {{PlanckPapers|planck2013-p03b}}.<br />
<br />
For the 30, 44 and 70 GHz, maps are corrected for zero level monopole by applying an offset correction, see LFI Calibration paper {{PlanckPapers|planck2013-p02b}} section 3.4 "Setting the zero levels in the maps". Note that the offset applied is indicated in the header as a comment keyword.<br />
<br />
''' The Zodiacal light and the Far-Side Lobes '''<br />
<br />
The figures below show the modeled Zodiacal light and Far Side Lobes projected onto the maps; they are simply the difference between the ''main product'' and the ''ZodiCorrected'' maps for the nominal mission. The units are given in the figures. The ''heat'' color table has been used in place of the standard Planck for clarity reasons. <br />
<center><br />
<gallery perrow=3 widths=260px heights=170px><br />
File: ZodiRes100.png | '''zodi/FSL rediduals - 100 GHz'''<br />
File: ZodiRes143.png | '''zodi/FSL rediduals - 143 GHz''' <br />
File: ZodiRes217.png | '''zodi/FSL rediduals - 217 GHz'''<br />
File: ZodiRes353.png | '''zodi/FSL rediduals - 353 GHz'''<br />
File: ZodiRes545.png | '''zodi/FSL rediduals - 545 GHz'''<br />
File: ZodiRes857.png | '''zodi/FSL rediduals - 857 GHz'''<br />
</gallery><br />
</center><br />
The effects of the FSLs are seen most clearly at the highest frequencies, as structures roughly symmetric about the center of the image, which corresponds to the location of the Galactic Centre, which is in turn the source of most of the radiation that is scattered into the FSLs.<br />
<br />
''' Artifacts near caustics of the scanning strategy '''<br />
<br />
The [[Survey scanning and performance|scanning strategy]] is such that regions around the Ecliptic poles are surveyed very deeply and compared to the average, and the transition from the nominal depth to the high depth, as shows on hit-count maps is very rapid, namely a few pixels, for a contrast of ~30. These transitions, or caustics in the maps, occur at different positions on the sky for different detectors, as the positions depend on their location in the focal plane of the instrument. As a result, when data from different detectors are combined to build a full channel map, the the weights of different detectors in the mix changes rapidly across the caustic, and given the remaining errors in the relative calibration of the detectors, a visible effect can be introduced in the maps, especially when the SNR is very high, i.e. at the highest frequencies and near bright regions like the Galactic Plane. Some examples are shown below.<br />
<br />
<center><br />
<gallery perrow=3 heights=260px widths=260pix ><br />
File: causta857.png | '''857 GHz intensity map around (272.5, -27)'''<br />
File: caustb857.png | '''857 GHz intensity map around (264.5, -37.5)'''<br />
File: caustc857.png | '''857 GHz intensity map around (98.5, 43)'''<br />
File: hita857.png | '''857 GHz hit count map around (272.5, -27)'''<br />
File: hitb857.png | '''857 GHz hit count map around (264.5, -37.5)'''<br />
File: hitc857.png | '''857 GHz hit count map around (98.5, 43)'''<br />
</gallery><br />
</center><br />
<br />
'''Production process'''<br />
<br />
<br />
Sky maps are produced by combining appropriately the data of all working detectors in a frequency channel over some period of the mission. They give the best estimate of the signal from the sky (unpolarised) after removal, as far as possible, of known systematic effects and of the dipole signals induced by the motion of the solar system in the CMB and of the Planck satellite in the solar system. In particular, they include the Zodiacal light emission (Zodi for short) and also the scattering from the far-side lobes of the beams (FSL). More on this below.<br />
<br />
''' HFI processing '''<br />
<br />
The inputs to the mapmaking are TOIs of signal that have been cleaned (as far as possible) of instrumental effects and calibrated in absorbed watts. While the processing involved is described in detail in the [[TOI processing|TOI processing]] section, we give a very brief summary here for convenience. That pipeline performs the following operations:<br />
<br />
; demodulation: this is performed around a variable level which is determined from the valid input data (a validity flag from a previous version of the processing is used for this purpose), and the data are converted to engineering units (V) using known conversion coefficients.<br />
; despiking: using the demodulated data converted to V (by the transfer function) the glitches are identified and fitted with templates. A glitch flag is produced that identifies the strongest part of the glitches, and a timeline of glitch tails is produced from the template fits, and subtracted from the demodulated timeline from step 1. Finally, the flagged ranges are replaced with data from an average over the pointing period (TBC)<br />
; dark template removal: the two dark bolometers are demodulated and despiked as above; the resulting timelines are then smoothed and used as an indicator of the overall temperature variations of the bolometer plate. Where the variations are consistent with each other, they are combined and removed from the bolometer signal timelines using appropriate coupling coefficients. The few percent of the data where they are not consistent are flagged on the timelines.<br />
; conversion to absorbed power: the timeline is converted to watts of absorbed power using the bolometer function. This includes a non-linearity correction; removal of the 4K cooler lines: the electromagnetic interference of the 4K cooler with the bolometer readout wires induces some sharp lines in the signal power spectra at frequencies of the 4K cooler's fundamental and its multiples, folded by the signal modulations. Fourier coefficients of the relevant lines are determined on a per-ring basis, and then removed from the data. The quality of the removal depends on the bolometer.<br />
; deconvolution by the time transfer function: this is done to correct for the non-instantaneous time response of the bolometers. The function itself is modeled using 4 parameters which are adjusted primarily on the planet data and also from comparisons of the northward and southward scans of the Galactic Plane. It is then removed using Fourier techniques, which has the side-effect of increasing the noise at high frequencies.<br />
; jump correction: removes some (relatively rare: 0.3 jumps per bolometer per pointing period, on average) jumps in the signal baseline. The jumps are detected characterized on smoothed TOIs, and corrected by adding a constant to part of the signal timeline. The origin of the jumps is not known.<br />
<br />
The results of this processing are a timeline of signal (in absorbed watts) and a ''valid data'' flag timeline for each of the 50 valid bolometers processed; these timelines contain the full sky signal, i.e., including the solar and orbital dipoles, the Zodiacal light, and contributions from the Far-Side lobes. The dipoles are necessary for the flux calibration and are removed at the mapmaking stage. The remaining two bolometers (143-8 and 535-3) show semi-random jumps in the signal level, typically jumping over 2-5 different ''pseudo-baseline'' levels, a behavior known as ''Random Telegraphic Signal'', so that these are commonly called the RTS bolometers. Finally, ring-level statistics of different types (mean, median, rms, kurtosis, etc.) are determined on a per-ring basis for all timelines, and a selection based on these statistics is used to discard anomalous rings, which are recorded in a ring-level flag for each valid bolometer timeline (see the [[TOI_processing#Discarded_rings| Discarded rings]] section). <br />
<br />
Throughout this processing, bright planets (Mars, Jupiter, Saturn, Uranus) and bright asteroids are masked in the timeline in order to avoid ringing effects in the processing. Since they move on the sky, the portion of the sky masked during one survey is observed during one, and no hole is left in the final map. In parallel, the planet data are processed in a similar way, but with different parameters for the despiking step, and without the final jump correction step. These results are processed separately to determine the beam shapes and the focal plane geometry.<br />
<br />
The pointing is determined starting from the AHF produced by MOC, which gives the direction and orientation of the LOS of a fiducial position in the focal plane at frequencies of 8Hz during stable pointing and 4 Hz during maneuvers (TBC for details, reference). This is interpolated to the times of data observation (ref to method), corrected for the wobble and other time-dependent offsets determined from the observed positions of a large number of sources around the sky, and finally converted to the LOS of each detector using the quaternions in the IMO (which are determined from observations of bright planets - see the [[Detector_pointing]] section). <br />
<br />
The mapmaking and calibration process is described in detail in the [[Map-making_LFI | Map-making]] section, where detailed references are found. In brief it consists of:<br />
<br />
; binning the TOI data onto ''rings'' : Healpix rings (HPRs) are used here, each ring containing the combined data of one pointing period. <br />
; flux calibration : at 100-353 GHz, the flux calibration factors are determined for each pointing period (or ring) from the solar-motion dipole, using the WMAP dipole as the reference, and after removal of the dipole signal induced by the motion of the Planck satellite in the solar system. This gain by ring is smoothed with a window of width 50 rings, which reveals an apparent variation of ~1-2% on a scale of 100s to 1000s of rings for the 100-217 GHz channels, and is applied. At 353GHz, where the solar motion dipole is weaker compared to the signal, no gain variation is detected (within the uncertainties), and a single fixed gain is applied to all rings. At 545 and 857 GHz the gain is determined from the observation of Uranus and Neptune (but not Jupiter which is too bright) and comparison to recent models made explicitly for this mission. A single gain is applied to all rings at these frequencies.<br />
; destriping : in order to remove low-frequency noise, an offset per ring is determined by minimizing the differences between HPRs at their crossings, and removed.<br />
; projection onto the map : the offset-corrected and flux-calibrated HPRs are projected onto Healpix maps, with the data of each bolometer weighted by a factor of 1/NET of that bolometer, and accounting for the slight different band transmission profiles of the bolometers in each band. <br />
<br />
These maps provide the main mission products. A second, reduced, set of maps, cleaned of the Zodiacal emission of the FSL leakage is also produced for the nominal mission and the two single surveys, but not for the half-rings (since the contribution would be the same for the two halves of each ring). For this purpose, the the Zodiacal emission and the FSL contamination, which are not fixed on the sky, are modeled separately at HPR-level, and subtracted from the signal HPR before projecting them onto the maps. <br />
<br />
Together with signal maps, hit count and variance maps are also produced. The hit maps give the (integer) number of valid TOI-level samples that contribute to the signal of each pixel. All valid samples are counted in the same way, i.e., there is no weighting factor applied. The variance maps project the white noise estimate, provided by the NETs, in the sky domain.<br />
<br />
''' LFI processing '''<br />
<br />
LFI maps were constructed with the Madam map-making code, version 3.7.4. The code is based on generalized destriping technique, where the correlated noise component is modeled as a sequence of constant offset, called baselines. A noise filter was used to constrain the baseline solution allowing the use of 1 second baselines.<br />
<br />
Radiometers were combined according to the horn-uniform weighting scheme to minimize systematics. The used weights are listed in [[Map-making LFI#Map-making|Map-making]]. The flagged samples were excluded from the analysis by setting their weights to $C_{w}^{-1}$ = 0. The galaxy region was masked out in the destriping phase, to reduce error arising from strong signal gradients. The polarization component was included in the analysis, although only the temperature maps are released. <br />
<br />
A detailed description of the map-making procedure is given in {{PlanckPapers|planck2013-p02}} and in section [[Map-making LFI#Map-making|Map-making]].<br />
<br />
'''Inputs'''<br />
<br />
<br />
''' HFI inputs '''<br />
<br />
* The cleaned TOIs of signal of each detector, together with their flags, produced by the [[TOI processing|TOI processing]] pipeline<br />
* The TOIs of pointing (quaternions), described in [[Detector_pointing]]<br />
* Bolometer-level characterization data, from the DPC's internal IMO (not distributed)<br />
* Planck orbit data used to compute and remove the earth dipole<br />
* WMAP solar dipole information used to calibrate the CMB channels<br />
* Planet models used to calibrate the Galactic channels.<br />
<br />
''' LFI inputs '''<br />
<br />
The Madam map-maker takes as an input:<br />
<br />
* The calibrated timelines (for details see [[TOI processing LFI|TOI Processing]])<br />
* The detector pointings (for details see [[Detector pointing|Detector pointing]])<br />
* The noise information in the form of three-parameter (white noise level ($\sigma$), slope, and knee frequency ($f_\mathrm{knee}$)) noise model (for details see [[The RIMO|RIMO]])<br />
<br />
'''Related products'''<br />
<br />
<br />
''' Masks '''<br />
<br />
Masks are provided of<br />
<br />
; the point sources<br />
: 15 masks are provided, three for the LFI (one mask for each frequency masking at the 4<math>\sigma</math> level) and 12 for the HFI (two masks for each frequency at the 5 and 10<math>\sigma</math> levels. For the HFI the masks can be used as they are, for the LFI they need to be downgraded to Nside=1024 except for the 70 GHz channel at Nside=2048 which does not need to be downgraded.<br />
<br />
; the Galactic Plane<br />
: 8 masks are provided giving 20, 40, 60, 70, 80, 90, 97, and 99% sky coverage in two different files, at Nside=2048. For the HFI they can be used as they are, for the LFI they need to be downgraded at Nside=1024 (note that if using the 70 GHZ at Nside=2048 no downgraded is needed)<br />
<br />
<br />
The masks are binary, in GALACTIC coordinates, and NESTED ordering. The table below give the filenames. <br />
<br />
<br />
{| class="wikitable" align="center" style="text-align:center" border="1" cellpadding="5" cellspacing="0" <br />
|+ '''FITS filenames for masks'''<br />
|-bgcolor="ffdead"<br />
! Frequency || LFI Point Source masks<br />
|-<br />
| '''30GHz''' || {{PLASingleFile|fileType=map|name=LFI_MASK_030-ps_2048_R1.00.fits|link=LFI_MASK_030-ps_2048_R1.00.fits}}<br />
|-<br />
| '''44GHz''' || {{PLASingleFile|fileType=map|name=LFI_MASK_044-ps_2048_R1.00.fits|link=LFI_MASK_044-ps_2048_R1.00.fits}}<br />
|-<br />
| '''70GHz''' || {{PLASingleFile|fileType=map|name=LFI_MASK_070-ps_2048_R1.00.fits|link=LFI_MASK_070-ps_2048_R1.00.fits}}<br />
|- bgcolor="ffdead"<br />
! colspan="2" | HFI Point Source masks<br />
|-<br />
| colspan="2" | {{PLASingleFile|fileType=map|name=HFI_Mask_PointSrc_2048_R1.10.fits|link=HFI_Mask_PointSrc_2048_R1.10.fits}}<br />
|- bgcolor="ffdead"<br />
! colspan="2" | Galactic Plane masks<br />
|-<br />
| colspan="2" | {{PLASingleFile|fileType=map|name=HFI_Mask_GalPlane_2048_R1.10.fits|link=HFI_Mask_GalPlane_2048_R1.10.fits}} <br />
|}<br />
<br />
<br />
The masks are shows below in a single figure. While this is quite clear for the Galactic Plane masks, it is less so for the point source masks, but it does give a clear perspective on how the latter are distributed over the sky.<br />
<br />
<center><br />
<gallery perrow=2 widths=300px heights=185px ><br />
File: HFI_GalPlaneMask.png | '''Galactic Plane masks'''<br />
File: HFI_PointSrcMask.png | '''PointSource masks'''<br />
</gallery><br />
</center><br />
<br />
''' File names '''<br />
<br />
<br />
The FITS filenames are of the form ''{H|L}FI_SkyMap_fff_nnnn_R1.nn_{coverage}_{type}.fits'', where ''fff'' are three digits to indicate the Planck frequency band, and ''nnnn'' is the Healpix Nside of the map, ''coverage'' indicates which part of the mission is covered, and the optional ''type'' indicates the subset of input data used. A full list of products, with links to them in the Archive, is given in the tables below.<br />
<br />
For the benefit of users who are only looking for the frequency maps with no additional information, we also provide a file combining the 9 frequency maps as separate columns in a single extension. The 9 columns in this file contain the intensity maps ONLY and no other information (hit maps and variance maps) is provided.<br />
<br />
{| class="wikitable" align="center" style="text-align:center" border="1" cellpadding="5" cellspacing="0" width=500px<br />
|+ '''FITS filenames'''<br />
|- bgcolor="ffdead"<br />
! Frequency || Full channel maps<br />
|-<br />
| '''30GHz''' || {{PLASingleFile|fileType=map|name=LFI_SkyMap_030_1024_R1.10_nominal.fits|link=LFI_SkyMap_030_1024_R1.10_nominal.fits}}<br />
|-<br />
| '''44GHz''' || {{PLASingleFile|fileType=map|name=LFI_SkyMap_044_1024_R1.10_nominal.fits|link=LFI_SkyMap_044_1024_R1.10_nominal.fits}}<br />
|-<br />
| '''70GHz''' || {{PLASingleFile|fileType=map|name=LFI_SkyMap_070_1024_R1.10_nominal.fits|link=LFI_SkyMap_070_1024_R1.10_nominal.fits}}<br />
|-<br />
| '''70GHz''' || {{PLASingleFile|fileType=map|name=LFI_SkyMap_070_2048_R1.10_nominal.fits|link=LFI_SkyMap_070_2048_R1.10_nominal.fits}}<br />
|-<br />
| '''100GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_100_2048_R1.10_nominal.fits|link=HFI_SkyMap_100_2048_R1.10_nominal.fits}}<br />
|-<br />
| '''143GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_143_2048_R1.10_nominal.fits|link=HFI_SkyMap_143_2048_R1.10_nominal.fits}}<br />
|-<br />
| '''217GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_217_2048_R1.10_nominal.fits|link=HFI_SkyMap_217_2048_R1.10_nominal.fits}}<br />
|-<br />
| '''353GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_353_2048_R1.10_nominal.fits|link=HFI_SkyMap_353_2048_R1.10_nominal.fits}}<br />
|-<br />
| '''545GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_545_2048_R1.10_nominal.fits|link=HFI_SkyMap_545_2048_R1.10_nominal.fits}}<br />
|-<br />
| '''857GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_857_2048_R1.10_nominal.fits|link=HFI_SkyMap_857_2048_R1.10_nominal.fits}}<br />
|- bgcolor="ffdead"<br />
! Frequency || Full channel, Zodi-corrected maps<br />
|-<br />
| '''100GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_100_2048_R1.10_nominal_ZodiCorrected.fits|link=HFI_SkyMap_100_2048_R1.10_nominal_ZodiCorrected.fits}} <br />
|-<br />
| '''143GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_143_2048_R1.10_nominal_ZodiCorrected.fits|link=HFI_SkyMap_143_2048_R1.10_nominal_ZodiCorrected.fits}}<br />
|-<br />
| '''217GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_217_2048_R1.10_nominal_ZodiCorrected.fits|link=HFI_SkyMap_217_2048_R1.10_nominal_ZodiCorrected.fits}}<br />
|-<br />
| '''353GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_353_2048_R1.10_nominal_ZodiCorrected.fits|link=HFI_SkyMap_353_2048_R1.10_nominal_ZodiCorrected.fits}}<br />
|-<br />
| '''545GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_545_2048_R1.10_nominal_ZodiCorrected.fits|link=HFI_SkyMap_545_2048_R1.10_nominal_ZodiCorrected.fits}}<br />
|-<br />
| '''857GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_857_2048_R1.10_nominal_ZodiCorrected.fits|link=HFI_SkyMap_857_2048_R1.10_nominal_ZodiCorrected.fits}}<br />
|- bgcolor="ffdead"<br />
! Frequency || Combined frequency maps<br />
|-<br />
| '''All''' || {{PLASingleFile|fileType=file|name=COM_MapSet_I-allFreqs_R1.10_nominal.fits|link=COM_MapSet_I-allFreqs_R1.10_nominal.fits}} <br />
|}<br />
<br />
<br />
{| class="wikitable" align="center" style="text-align:center" border="1" cellpadding="5" cellspacing="0" width=850px<br />
|+ '''FITS filenames'''<br />
|- bgcolor="ffdead"<br />
! Frequency || Survey 1 maps || Survey 2 maps<br />
|-<br />
| '''30GHz''' || {{PLASingleFile|fileType=map|name=LFI_SkyMap_030_1024_R1.10_survey_1.fits|link=LFI_SkyMap_030_1024_R1.10_survey_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=LFI_SkyMap_030_1024_R1.10_survey_2.fits|link=LFI_SkyMap_030_1024_R1.10_survey_2.fits}}<br />
|-<br />
| '''44GHz''' || {{PLASingleFile|fileType=map|name=LFI_SkyMap_044_1024_R1.10_survey_1.fits|link=LFI_SkyMap_044_1024_R1.10_survey_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=LFI_SkyMap_044_1024_R1.10_survey_2.fits|link=LFI_SkyMap_044_1024_R1.10_survey_2.fits}}<br />
|-<br />
| '''70GHz''' || {{PLASingleFile|fileType=map|name=LFI_SkyMap_070_1024_R1.10_survey_1.fits|link=LFI_SkyMap_070_1024_R1.10_survey_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=LFI_SkyMap_070_1024_R1.10_survey_2.fits|link=LFI_SkyMap_070_1024_R1.10_survey_2.fits}}<br />
|-<br />
| '''70GHz''' || {{PLASingleFile|fileType=map|name=LFI_SkyMap_070_2048_R1.10_survey_1.fits|link=LFI_SkyMap_070_2048_R1.10_survey_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=LFI_SkyMap_070_2048_R1.10_survey_2.fits|link=LFI_SkyMap_070_2048_R1.10_survey_2.fits}}<br />
|-<br />
| '''100GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_100_2048_R1.10_survey_1.fits|link=HFI_SkyMap_100_2048_R1.10_survey_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_100_2048_R1.10_survey_2.fits|link=HFI_SkyMap_100_2048_R1.10_survey_2.fits}}<br />
|-<br />
| '''143GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_143_2048_R1.10_survey_1.fits|link=HFI_SkyMap_143_2048_R1.10_survey_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_143_2048_R1.10_survey_2.fits|link=HFI_SkyMap_143_2048_R1.10_survey_2.fits}}<br />
|-<br />
| '''217GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_217_2048_R1.10_survey_1.fits|link=HFI_SkyMap_217_2048_R1.10_survey_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_217_2048_R1.10_survey_2.fits|link=HFI_SkyMap_217_2048_R1.10_survey_2.fits}}<br />
|-<br />
| '''353GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_353_2048_R1.10_survey_1.fits|link=HFI_SkyMap_353_2048_R1.10_survey_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_353_2048_R1.10_survey_2.fits|link=HFI_SkyMap_353_2048_R1.10_survey_2.fits}}<br />
|-<br />
| '''545GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_545_2048_R1.10_survey_1.fits|link=HFI_SkyMap_545_2048_R1.10_survey_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_545_2048_R1.10_survey_2.fits|link=HFI_SkyMap_545_2048_R1.10_survey_2.fits}}<br />
|-<br />
| '''857GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_857_2048_R1.10_survey_1.fits|link=HFI_SkyMap_857_2048_R1.10_survey_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_857_2048_R1.10_survey_2.fits|link=HFI_SkyMap_857_2048_R1.10_survey_2.fits}}<br />
|- bgcolor="ffdead"<br />
! Frequency || Survey 1 Zodi-corrected maps || Survey 2 Zodi-corrected maps<br />
|-<br />
| '''100GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_100_2048_R1.10_survey_1_ZodiCorrected.fits|link=HFI_SkyMap_100_2048_R1.10_survey_1_ZodiCorrected.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_100_2048_R1.10_survey_2_ZodiCorrected.fits|link=HFI_SkyMap_100_2048_R1.10_survey_2_ZodiCorrected.fits}}<br />
|-<br />
| '''143GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_143_2048_R1.10_survey_1_ZodiCorrected.fits|link=HFI_SkyMap_143_2048_R1.10_survey_1_ZodiCorrected.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_143_2048_R1.10_survey_2_ZodiCorrected.fits|link=HFI_SkyMap_143_2048_R1.10_survey_2_ZodiCorrected.fits}}<br />
|-<br />
| '''217GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_217_2048_R1.10_survey_1_ZodiCorrected.fits|link=HFI_SkyMap_217_2048_R1.10_survey_1_ZodiCorrected.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_217_2048_R1.10_survey_2_ZodiCorrected.fits|link=HFI_SkyMap_217_2048_R1.10_survey_2_ZodiCorrected.fits}}<br />
|-<br />
| '''353GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_353_2048_R1.10_survey_1_ZodiCorrected.fits|link=HFI_SkyMap_353_2048_R1.10_survey_1_ZodiCorrected.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_353_2048_R1.10_survey_2_ZodiCorrected.fits|link=HFI_SkyMap_353_2048_R1.10_survey_2_ZodiCorrected.fits}}<br />
|-<br />
| '''545GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_545_2048_R1.10_survey_1_ZodiCorrected.fits|link=HFI_SkyMap_545_2048_R1.10_survey_1_ZodiCorrected.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_545_2048_R1.10_survey_2_ZodiCorrected.fits|link=HFI_SkyMap_545_2048_R1.10_survey_2_ZodiCorrected.fits}}<br />
|-<br />
| '''857GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_857_2048_R1.10_survey_1_ZodiCorrected.fits|link=HFI_SkyMap_857_2048_R1.10_survey_1_ZodiCorrected.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_857_2048_R1.10_survey_2_ZodiCorrected.fits|link=HFI_SkyMap_857_2048_R1.10_survey_2_ZodiCorrected.fits}}<br />
|- bgcolor="ffdead"<br />
! Frequency || Half-ring 1 maps ||Half-ring 2 maps<br />
|-<br />
| '''30GHz''' || {{PLASingleFile|fileType=map|name=LFI_SkyMap_030_1024_R1.10_nominal_ringhalf_1.fits|link=LFI_SkyMap_030_1024_R1.10_nominal_ringhalf_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=LFI_SkyMap_030_1024_R1.10_nominal_ringhalf_2.fits|link=LFI_SkyMap_030_1024_R1.10_nominal_ringhalf_2.fits}}<br />
|-<br />
| '''44GHz''' || {{PLASingleFile|fileType=map|name=LFI_SkyMap_044_1024_R1.10_nominal_ringhalf_1.fits|link=LFI_SkyMap_044_1024_R1.10_nominal_ringhalf_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=LFI_SkyMap_044_1024_R1.10_nominal_ringhalf_2.fits|link=LFI_SkyMap_044_1024_R1.10_nominal_ringhalf_2.fits}}<br />
|-<br />
| '''70GHz''' || {{PLASingleFile|fileType=map|name=LFI_SkyMap_070_1024_R1.10_nominal_ringhalf_1.fits|link=LFI_SkyMap_070_1024_R1.10_nominal_ringhalf_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=LFI_SkyMap_070_1024_R1.10_nominal_ringhalf_2.fits|link=LFI_SkyMap_070_1024_R1.10_nominal_ringhalf_2.fits}}<br />
|-<br />
| '''70GHz''' || {{PLASingleFile|fileType=map|name=LFI_SkyMap_070_2048_R1.10_nominal_ringhalf_1.fits|link=LFI_SkyMap_070_2048_R1.10_nominal_ringhalf_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=LFI_SkyMap_070_2048_R1.10_nominal_ringhalf_2.fits|link=LFI_SkyMap_070_2048_R1.10_nominal_ringhalf_2.fits}}<br />
|-<br />
| '''100GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_100_2048_R1.10_nominal_ringhalf_1.fits|link=HFI_SkyMap_100_2048_R1.10_nominal_ringhalf_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_100_2048_R1.10_nominal_ringhalf_2.fits|link=HFI_SkyMap_100_2048_R1.10_nominal_ringhalf_2.fits}}<br />
|-<br />
| '''143GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_143_2048_R1.10_nominal_ringhalf_1.fits|link=HFI_SkyMap_143_2048_R1.10_nominal_ringhalf_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_143_2048_R1.10_nominal_ringhalf_2.fits|link=HFI_SkyMap_143_2048_R1.10_nominal_ringhalf_2.fits}}<br />
|-<br />
| '''217GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_217_2048_R1.10_nominal_ringhalf_1.fits|link=HFI_SkyMap_217_2048_R1.10_nominal_ringhalf_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_217_2048_R1.10_nominal_ringhalf_2.fits|link=HFI_SkyMap_217_2048_R1.10_nominal_ringhalf_2.fits}}<br />
|-<br />
| '''353GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_353_2048_R1.10_nominal_ringhalf_1.fits|link=HFI_SkyMap_353_2048_R1.10_nominal_ringhalf_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_353_2048_R1.10_nominal_ringhalf_2.fits|link=HFI_SkyMap_353_2048_R1.10_nominal_ringhalf_2.fits}}<br />
|-<br />
| '''545GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_545_2048_R1.10_nominal_ringhalf_1.fits|link=HFI_SkyMap_545_2048_R1.10_nominal_ringhalf_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_545_2048_R1.10_nominal_ringhalf_2.fits|link=HFI_SkyMap_545_2048_R1.10_nominal_ringhalf_2.fits}}<br />
|-<br />
| '''857GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_857_2048_R1.10_nominal_ringhalf_1.fits|link=HFI_SkyMap_857_2048_R1.10_nominal_ringhalf_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_857_2048_R1.10_nominal_ringhalf_2.fits|link=HFI_SkyMap_857_2048_R1.10_nominal_ringhalf_2.fits}}<br />
|}<br />
<br />
''' FITS file structure '''<br />
<br />
<br />
[[File:FITS_FreqMap.png | 500px | right | thumb | '''FITS file structure''']]<br />
<br />
The FITS files for the sky maps contain a minimal primary header with no data, and a ''BINTABLE'' extension (EXTENSION 1, EXTNAME = ''FREQ-MAP'') containing the data. The structure is shows schematically in the figure at right. <br />
<br />
The ''FREQ-MAP'' extension contains is a 3-column table that contain the signal, hit-count and variance maps, all in Healpix format, in columns 1, 2, and 3, respectively. The number of rows is 50331648 for HFI and LFI 70 GHz at Nside=2048 and 12582912 for LFI maps at Nside=1024 (N.B: Npix = 12 Nside^2). The three columns are ''I_STOKES'' for the intensity (or temperature) signal, ''HIT'' for the hit-count and ''II_COV'' for the variance. The exact order of the columns in the figure is indicative only, and the details can be found in the keywords. <br />
<br />
Keywords indicate the coordinate system (GALACTIC), the Healpix ordering scheme (NESTED), the units (K_cmb or MJy/sr) of each column, and of course the frequency channel (FREQ). The COMMENT fields give a one-line summary of the product, and some other information useful for traceability within the DPCs. The original filename is also given in the ''FILENAME'' keyword as are the datasum and the md5 checksum for the extension. The ''BAD_DATA'' keyword gives the value used by Healpix to indicate pixels for which no signal is present (these will also have a hit-count value of 0). The COMMENT fields give further information including some traceability data for the DPC's. The main parameters are summarised below:<br />
<br />
<br />
{| border="1" cellpadding="3" cellspacing="0" align="center" style="text-align:left" width=800px<br />
|+ '''Sky map file data structure'''<br />
|- bgcolor="ffdead" <br />
!colspan="4" | 1. EXTNAME = 'FREQ-MAP' : Data columns<br />
|- bgcolor="ffdead" <br />
! Column Name || Data Type || Units || Description<br />
|-<br />
|I_STOKES || Real*4 || K_cmb or MJy/sr || The signal map<br />
|-<br />
|HITS || Int*4 || none || The hit-count map<br />
|-<br />
|II_COV || Real*4 || K_cmb<sup>2</sup> or (MJy/sr)<sup>2</sup> || The variance map<br />
|- bgcolor="ffdead" <br />
! Keyword || Data Type || Value || Description<br />
|-<br />
|PIXTYPE || string || HEALPIX ||<br />
|-<br />
|COORDSYS || string || GALACTIC ||Coordinate system <br />
|-<br />
|ORDERING || string || NESTED || Healpix ordering<br />
|-<br />
|NSIDE || Int || 1024 or 2048 || Healpix Nside <br />
|-<br />
|FIRSTPIX || Int*4 || 0 || First pixel number<br />
|-<br />
|LASTPIX || Int*4 || 12582911 or 50331647 || Last pixel number<br />
|-<br />
|FREQ || string || nnn || The frequency channel <br />
|}<br />
<br />
<br />
The same structure applies to all ''SkyMap'' products, independent of whether they are full channel, survey of half-ring. The distinction between the types of maps is present in the FITS filename (and in the traceability comment fields).<br />
<br />
''' References'''<br />
<br />
<References /><br />
<br />
<br />
</div><br />
</div><br />
<br />
<br />
<br />
[[Category:Mission products|002]]</div>Azaccheihttps://wiki.cosmos.esa.int/planck-legacy-archive/index.php?title=Frequency_maps&diff=14112Frequency maps2018-07-06T13:47:18Z<p>Azacchei: /* File names */</p>
<hr />
<div>{{DISPLAYTITLE:Frequency maps in Temperature and Polarization}}<br />
==General description==<br />
<br />
Sky maps give the best estimate of the intensity and polarization (Stokes <i>Q</i> and <i>U</i> components), if available, of the signal from the sky after removal, as far as possible, of known systematic effects (mostly instrumental, but including also the solar and Earth-motion dipoles, Galactic stray light, and the zodiacal light). The Planck Collaboration has made three releases of maps, in 2013, 2015 and 2018. This section describes the 2018 release. For descriptions of the other two releases, please go to 2013, and 2015.<br />
<br />
In the 2013, 2015 and 2018 releases, sky maps are provided for the full Planck mission using all valid detectors in each frequency channel, and also for various subsets obtained by splitting the mission into various time ranges or into subsets of the detectors in a given channel, or by considering only odd or even pointing periods. These products are especially interesting for characterization purposes (see also the [[HFI-Validation | data validation]] section), though some are also useful for the study of source variability. The details of the start and end of the time ranges are given in the table below. <br />
<br />
For this (2018) release, HFI is providing a more limited subset of maps that include the full channel maps, the half-mission and the odd-even ring splits. Also, note that for the 353 GHz band, both full channel and PSBs only maps are provided, and that by default it is the PBS-only maps that are served.<br />
<br />
<br />
{| border="1" cellpadding="3" cellspacing="0" align="center" style="text-align:left" width=800px<br />
|+ '''Ranges for mission and surveys'''<br />
|- bgcolor="ffdead" <br />
! Range || ODs || HFI rings || pointing-IDs || Comment<br />
|-<br />
|Nominal mission || 91 - 563 || 240 - 14723 || 00004200 - 03180200 ||<br />
|-<br />
|Full mission || 91 - 974 || 240 - 27005 || 00004200 - 05322620 || For HFI<br />
|-<br />
|Full mission || 91 - 1543 || n/a || 00004200 - 06511160 || For LFI<br />
|-<br />
|Survey 1 || 91 - 270 || 240 - 5720 || 00004200 - 01059820 ||<br />
|-<br />
|Survey 2 || 270 - 456 || 5721 - 11194 || 01059830 - 02114520 ||<br />
|-<br />
|Survey 3 || 456 - 636 || 11195 - 16691 || 02114530 - 03193660 ||<br />
|-<br />
|Survey 4 || 636 - 807 || 16692 - 21720 || 03193670 - 04243900 ||<br />
|-<br />
|Survey 5 || 807 - 974 || 21721 - 26050 || 05267180 - 05322590 || End of mission for HFI<br />
|-<br />
|Survey 5 || 807 - 993 || n/a || 05267180 - 06344800 || End of survey for LFI<br />
|-<br />
|Survey 6 || 993 - 1177 || n/a || 06344810 - 06398120 || LFI only <br />
|-<br />
|Survey 7 || 1177 - 1358 || n/a || 06398130 - 06456410 || LFI only <br />
|-<br />
|Survey 8 || 1358 - 1543 || n/a || 06456420 - 06511160 || LFI only <br />
|-<br />
|HFI mission-half-1 || 91 - 531 || 240 - 13471 || 00004200 - 03155580 ||<br />
|-<br />
|HFI mission-half-2 || 531 - 974 || 13472 - 27005 || 03155590 - 05322590 ||<br />
|-<br />
|LFI Year 1 || 91 - 456 || n/a || 00004200 - 02114520 ||<br />
|-<br />
|LFI Year 2 || 456 - 807 || n/a || 02114530 - 04243900 ||<br />
|-<br />
|LFI Year 3 || 807 - 1177 || n/a || 05267180 - 06398120 ||<br />
|-<br />
|LFI Year 4 || 1177 - 1543 || n/a || 06398130 - 06511160 ||<br />
|-<br />
|}<br />
<br />
To help in further processing, there are also masks of the Galactic plane and of point sources, each provided for several different depths. <br />
<br />
All sky maps are in HEALPix format, with <i>N</i><sub>side</sub>=1024 (for LFI 30, 44, and 70GHz) and 2048 (for LFI 70GHz and HFI), in Galactic coordinates, and with nested ordering. <br />
<br />
'''WARNING''': The HEALPix convention for polarization is <b>not</b> the same as the IAU convention ([[#Polarization convention used in the Planck project|Section 8 on this page]]).<br />
<br />
The signal is given in units of K<sub>CMB</sub> for 30 to 353 GHz, and of MJy.sr<sup>-1</sup> (for a constant &nu;<i>I</i><sub>&nu;</sub> energy distribution) for 545 and 857 GHz. For each frequency channel, the intensity and polarization maps are packaged into a "BINTABLE" extension of a FITS file together with a hit-counts map (or "hits map", for short, giving the number of observation samples that are accumulated in a pixel, all detectors combined) and with the variance and covariance maps. Additional information is given in the FITS file header. The structure of the FITS file is given in the [[#FITS_file_structure | FITS file structure]] section below.<br />
<br />
==Production process==<br />
<br />
Sky maps are produced by appropriately combining the data from all working detectors in a frequency channel over some period of the mission. They give the best estimate of the signal from the sky (unpolarized) after removal, as far as possible, of known systematic effects and of the dipole signals induced by the motion of the solar system in the CMB and of the Planck satellite in the solar system. In particular, they include the zodiacal light emission ("zodi" for short) and also the scattering from the far sidelobes of the beams (FSL). More on this below.<br />
<br />
=== HFI processing ===<br />
<br />
The mapmaking and calibration process is described in detail in the [[Map-making_LFI | mapmaking]] section and in the {{PlanckPapers|planck2016-XLVI}} paper, where detailed references can be found. In brief, the timelines are cleaned and calibrated and converted into HealPix rings (HPRs), then ''SRoll'' is applied to destripe them in polarised space (removal of very low frequency noise by minimising differences at ring crossing points), to remove knows systematic effects (including the flux calibration), and to project them onto a HealPix map.<br />
<br />
The processing yields maps of the signal, hit counts and auto- and cross-variance maps for the 6 full channel and for a pseudo-channel built from the 353 PSBs only. For each channel HFI provides <br />
* a map for the full mission<br />
* two maps for each half-mission<br />
* two maps for built from odd or even rings only<br />
<br />
for a total of 35 maps. <br />
<br />
==== PR3 HFI products ====<br />
<br />
===== Healpix Pixel Rings (HPRs) =====<br />
''SRoll'' main products are the HFI frequency maps. Nevertheless, we also make available the Healpix Pixel Rings (HPRs) of those maps, ie. the data before projection. See [[Healpix_Rings_HFI| description of those files]].<br />
<br />
===== Frequency maps =====<br />
<br />
The 35 HFI frequency maps of the PR3 Legacy Release are the followings:<br />
<br />
{| border="1" cellpadding="3" cellspacing="0" align="center" style="text-align:left" width=800px<br />
|+ '''PR3 HFI frequency maps'''<br />
|- bgcolor="ffdead"<br />
!<br />
!100 GHz<br />
!143 GHz<br />
!217 GHz<br />
!353 GHz<br />
!353_PSB GHz<br />
!545 GHz<br />
!857 GHz<br />
|-<br />
| Full mission<br />
| I, Q, U<br />
| I, Q, U<br />
| I, Q, U<br />
| I, Q, U<br />
| I, Q, U<br />
| I<br />
| I<br />
|-<br />
| Half mission 1<br />
| I, Q, U<br />
| I, Q, U<br />
| I, Q, U<br />
| I, Q, U<br />
| I, Q, U<br />
| I<br />
| I<br />
|-<br />
| Half mission 2<br />
| I, Q, U<br />
| I, Q, U<br />
| I, Q, U<br />
| I, Q, U<br />
| I, Q, U<br />
| I<br />
| I<br />
|-<br />
| Odd rings<br />
| I, Q, U<br />
| I, Q, U<br />
| I, Q, U<br />
| I, Q, U<br />
| I, Q, U<br />
| I<br />
| I<br />
|-<br />
| Even rings<br />
| I, Q, U<br />
| I, Q, U<br />
| I, Q, U<br />
| I, Q, U<br />
| I, Q, U<br />
| I<br />
| I<br />
|}<br />
<br />
See [[Frequency_maps|description of those files]]. These maps are available on the [[https://www.cosmos.esa.int/web/planck/pla| Planck Legacy Archive]].<br />
<br />
<br />
=== LFI processing ===<br />
LFI maps were constructed with the MADAM mapmaking code, version 3.7.4. The code is based on a generalized destriping technique, where the correlated noise component is modelled as a sequence of constant offsets, called "baselines". A noise filter was used to constrain the baseline solution, allowing the use of 0.25-s and 1-s baselines for the 30 and 44GHz, and 70 GHz channels, respectively. See section 6 of {{PlanckPapers|planck2016-l02}}.<br />
<br />
<br />
Radiometers were combined according to the horn-uniform weighting scheme to minimize systematics. The flagged samples were excluded from the analysis by setting their weights to <i>C</i><sub>w</sub><sup>-1</sup> = 0. The Galaxy region was masked out in the destriping phase, to reduce errors arising from strong signal gradients. The polarization component was included in the analysis. <br />
<br />
; Dipole and Far Side Lobe correction: Input timelines are cleaned by the 4&pi;-convolved dipole and Galactic stray light, obtained as a convolution of the 4&pi; in-band far sidelobes and Galactic simulations, as explained in {{PlanckPapers|planck2016-l02}}. <br />
<br />
Scaling of the maps due to beam effects is taken into account in the LFI's beam functions (as provided in [[The_RIMO|the RIMO]]) which should be used for analysis of diffuse components.<br />
<br />
; Bandpass leakage correction :LFI high-resolution maps have been reseleased corrected for bandpass leakage or uncorrected. Further details about the procedure used to generate the bandpass correction maps can be found in section 7 of {{PlanckPapers|planck2016-l02}}.<br />
<br />
; Map zero-level : The 30, 44 and 70 GHz, maps are corrected for a zero-level monopole by applying an offset correction (see the LFI Calibration paper, {{PlanckPapers|planck2014-a06}}). Note that the offset applied is indicated in the header as a comment keyword.<br />
<br />
A detailed description of the mapmaking procedure is given in {{PlanckPapers|planck2013-p02}}, {{PlanckPapers|planck2014-a03}}, {{PlanckPapers|planck2014-a07}} and in the [[Map-making LFI#Map-making|Mapmaking]] section here, in {{PlanckPapers|planck2016-l02}} only a summary is reported.<br />
<br />
==Types of map ==<br />
<br />
=== Full-mission, full-channel maps (7 HFI, 4 LFI)===<br />
<br />
Full channel maps are built using all the valid detectors of a frequency channel and cover either the full or the nominal mission. For HFI, the 143-8 and 545-3 bolometers are rejected entirely, since they are seriously affected by RTS noise. HFI provides the Q and U components for the 100, 143, 217 and 353 GHz channels only. LFI provides the <i>I</i>, <i>Q</i>, and <i>U</i> maps for all the channels. Note that the HFI and LFI <i>Q</i> and <i>U</i> maps are corrected for bandpass leakage, version without correction for LFi is also provided. The <i>I</i>, <i>Q</i>, and <i>U</i> maps are displayed in the figures below. The colour range here is set using a histogram equalization scheme (from HEALPix) that is useful for these non-Gaussian data fields. For visualization purposes, the <i>Q</i> and <i>U</i> maps shown here have been smoothed with a 1&deg; Gaussian kernel, otherwise they look like noise to the naked eye. The 70 GHz full map is also available at <i>N</i><sub>side</sub>=2048.<br />
<br />
The high dynamic range colour scheme of the Planck maps is described [https://wiki.cosmos.esa.int/planck-legacy-archive/index.php/Planck_high_dynamic_range_colour_palette here].<br />
<br />
<center><br />
<gallery style="padding:0 0 0 0;" perrow=3 widths=260px heights=160px> <br />
File: LFI_030GHz_dx12_I.png| '''Full mission <i>I</i>, 30 GHz.'''<br />
File: LFI_044GHz_dx12_I.png| '''Full mission <i>I</i>, 44 GHz.'''<br />
File: LFI_070GHz_dx12_I.png| '''Full mission <i>I</i>, 70 GHz.'''<br />
File: SkyMap100e.png| '''Full mission <i>I</i>, 100 GHz.'''<br />
File: SkyMap143e.png| '''Full mission <i>I</i>, 143 GHz.'''<br />
File: SkyMap217e.png| '''Full mission <i>I</i>, 217 GHz.'''<br />
File: SkyMap353e.png| '''Full mission <i>I</i>, 353 GHz.'''<br />
File: SkyMap545e.png| '''Full mission <i>I</i>, 545 GHz.'''<br />
File: SkyMap857e.png| '''Full mission <i>I</i>, 857 GHz.'''<br />
</gallery><br />
</center><br />
<br><br />
<center><br />
<gallery style="padding:0 0 0 0;" perrow=3 widths=260px heights=160px> <br />
File: LFI_030GHz_dx12_Q.png| '''Full mission <i>Q</i>, 30 GHz.'''<br />
File: LFI_044GHz_dx12_Q.png | '''Full mission <i>Q</i>, 44 GHz.'''<br />
File: LFI_070GHz_dx12_Q.png | '''Full mission <i>Q</i>, 70 GHz.'''<br />
File: HFI_Skymap_100_full_bplcorrected_sm1deg_Qb.png | '''Full mission <i>Q</i>, 100 GHz.'''<br />
File: HFI_Skymap_143_full_bplcorrected_sm1deg_Qb.png | '''Full mission <i>Q</i>, 143 GHz.'''<br />
File: HFI_Skymap_217_full_bplcorrected_sm1deg_Qb.png | '''Full mission <i>Q</i>, 217 GHz.'''<br />
File: HFI_Skymap_353_full_bplcorrected_sm1deg_Qb.png | '''Full mission <i>Q</i>, 353 GHz.'''<br />
</gallery><br />
</center><br />
<br><br />
<center><br />
<gallery style="padding:0 0 0 0;" perrow=3 widths=260px heights=160px> <br />
File: LFI_030GHz_dx12_U.png| '''Full mission <i>U</i>, 30 GHz.'''<br />
File: LFI_044GHz_dx12_U.png | '''Full mission <i>U</i>, 44 GHz.'''<br />
File: LFI_070GHz_dx12_U.png | '''Full mission <i>U</i>, 70 GHz.'''<br />
File: HFI_Skymap_100_full_bplcorrected_sm1deg_Ub.png | '''Full mission <i>U</i>, 100 GHz.'''<br />
File: HFI_Skymap_143_full_bplcorrected_sm1deg_Ub.png | '''Full mission <i>U</i>, 143 GHz.'''<br />
File: HFI_Skymap_217_full_bplcorrected_sm1deg_Ub.png | '''Full mission <i>U</i>, 217 GHz.'''<br />
File: HFI_Skymap_353_full_bplcorrected_sm1deg_Ub.png | '''Full mission <i>U</i>, 353 GHz.'''<br />
</gallery><br />
<br />
</center><br />
<br />
=== Full mission light maps, full channel maps (7 HFI, 7 LFI)===<br />
<br />
These maps are based on the Full mission maps but contain fewer columns, IQU from 30 to 353 GHz, and I only at 545 and 857 GHz. These maps have been produced to reduce the transfer time of the most downloaded frequency full mission maps.<br />
<br />
=== Single-survey, full-channel maps (35 LFI)===<br />
<br />
Single-survey maps are built using all valid detectors of a frequency channel; they separately cover the different sky surveys. The surveys are defined as the times over which the satellite spin axis rotates by 180&deg;, which, due to the position of the detectors in the focal plane does not cover the full sky, but a fraction between about 80% and 90%, depending on detector position. During adjacent surveys the sky is scanned in opposite directions (more precisely it is the ecliptic equator that is scanned in opposite directions). While these are useful to investigate variable sources, they are also used to study the systematics of the time-response of the detectors as they scan bright sources, like the Galactic Plane, in different directions during different survey. Note that the HFI and LFI missions cover five and eight surveys, respectively, and in the case of HFI the last survey in incomplete.<br />
The 70 GHz survey maps are available also at <i>N</i><sub>side</sub>=2048. Note that LFI provides a special survey-map combination used in the low-&#8467; analysis; this maps, available at the three LFI frequencies, 30, 44, and 70 GHz, was built using the combination of Surveys 1, 3, 5, 6, 7, and 8.<br />
<br />
=== Year maps, full-channel maps (16 LFI)===<br />
<br />
These maps are built using the data of Surveys 1+2, Surveys 3+4, and so forth. They are used to study long-term systematic effects. The 70 GHz years maps are available also at <i>N</i><sub>side</sub>=2048.<br />
<br />
===Half-mission maps, full-channel maps (14 HFI, 12 LFI)===<br />
<br />
For HFI, the half mission is defined after eliminating those rings that are discarded for all bolometers, many of which occurred during the 5th survey when the "End-of-Life" tests were performed. The remaining rings are divided in half to define the two halves of the mission. This exercise is done for the full mission only.<br />
<br />
For LFI, instead of the half-mission maps, the following year combinations have been created: Year 1+2, Year 1+3, Year 2+4, Year 3+4,<br />
<br />
===Full mission, single-detector maps (22 LFI)===<br />
<br />
For LFI, all the 22 Radiometers maps are available, and (obviously) only in Stokes <i>I</i>.<br />
<br />
===Full-mission, detector-set or detector-pairs maps (8 LFI)===<br />
<br />
The objective here is to build independent temperature (<i>I</i>) and polarization (<i>Q</i> and <i>U</i>) maps using the two pairs of polarization-sensitive detectors of each channel where they are available, i.e., for the 44-353 GHz channels. The table below indicates which detectors were used to build each detector set (detset).<br />
<br />
{| border="1" cellpadding="3" cellspacing="0" align="center" style="text-align:left" width=600px<br />
|+ '''Definition of LFI detector pairs'''<br />
|- bgcolor="ffdead" <br />
!Frequency || Horn pair || Comment <br />
|-<br />
|44 GHz || 24 || This map is only in temperature<br />
|-<br />
|44 GHz || 25 and 26 || <br />
|-<br />
|70 GHz || 18 and 23 || Available also at <i>N</i><sub>side</sub>=2048<br />
|-<br />
|70 GHz || 19 and 22 || Available also at <i>N</i><sub>side</sub>=2048<br />
|-<br />
|70 GHz || 20 and 21 || Available also at <i>N</i><sub>side</sub>=2048<br />
|}<br />
<br />
===Half-ring maps (62 LFI)===<br />
<br />
These maps are similar to the ones described above, but are built using only the first or the second halves of each ring (or pointing period). The HFI provides half-ring maps for the full mission only, as well as for the full channel, the detsets, and the single bolometers. The LFI provides half-ring maps for the full mission in each channel (70 GHz also at <i>N</i><sub>side</sub>=2048), for the full-mission radiometers, and for the full-mission horn pairs.<br />
<br />
=== Odd and even rings maps (14 HFI)<br />
<br />
As the name indicates, these are generated by using only the odd or only the even rings.<br />
<br />
=== Caveats and known issues ===<br />
<br />
'''TBC'''<br />
<br />
==== Caveats when using the HFI frequency maps ====<br />
Some imperfections have shown up in the tests of the HFI PR3 maps that were previously hidden by higher-level systematics in the previous PR2 data. These lead to guidelines for the proper use of the HFI PR3 data.<br />
<br />
===== Monopoles =====<br />
Monopoles, which cannot be extracted from Planck data alone, are adjusted at each frequency (as was done in the previous PR2 release). For component separation, this provides maps that can be used directly in combination with other tracers.<br />
This monopole includes a CIB model, a diffuse ISM signal adjusted on the HI tracer, and a zodiacal emission signal adjusted to the proper absolute intensity.<br />
<br />
=====Use of the 353 GHz SWBs ===== <br />
We deliver two data sets: the recommended one not using the 353 GHz SWBs data, and the other one including the 353 GHz SWBs for specific use like, for example, increasing the signal to noise level at high multipoles.<br />
<br />
===== Color correction and component separation=====<br />
Different responses between bolometers to different foregrounds cannot be used with the PR3 release to extract component maps. Single bolometer maps computed by Sroll in a frequency band, are all adjusted by construction to the band average response.<br />
<br />
===== Sub-pixel effect in very bright regions===== <br />
The bandpass corrections have been optimized for high latitude regions which implied to reduce the noise of the CO and dust bandpass templates to avoid the introduction of significant correlated noise. The effect is negligible for dust but not for CO in very bright regions. See [[subpixel_HFI|detailled description]].<br />
<br />
===== Solar dipole residual===== <br />
The ''Planck'' 2015 Solar dipole is removed from the PR3 HFI maps to be consistent with LFI maps and to facilitate comparison with the previous PR2 ones. The best Solar dipole determination from HFI PR3 data shows a small shift in direction of about 1', but a 1.8 &mu;K lower amplitude. Removal of the ''Planck'' 2015 Solar dipole thus leaves a small but non-negligible dipole residual in the HFI PR3 maps. To correct for this, and adjust maps at the best photometric calibration, users of the HFI PR3 maps should:<br />
# put back into the maps the ''Planck'' 2015 Solar dipole (d,l,b)= (3364.5 &plusmn; 2.0 &mu;K, 264.00 &plusmn; 0.03&deg;, 48.24 &plusmn; 0.02&deg;),<br />
# include the [[#Calibration accuracy|absolute calibration frequency bias]], i.e., multiply by 1 minus the calibration bias,<br />
# lastly, remove the [[#HFI 2018 Solar dipole|HFI 2018 Solar dipole]].<br />
<br />
==Inputs==<br />
=== HFI inputs ===<br />
<br />
The HFI mapmaking takes as input:<br />
* the cleaned TOIs of the signal from each detector, together with their flags, produced by the [[TOI processing|TOI processing]] pipeline;<br />
* the TOIs of pointing (quaternions), described in [[Detector_pointing|Detector pointing]];<br />
* bolometer-level characterization data, from the DPC's internal IMO (not distributed);<br />
* Planck orbit data, used to compute and remove the Earth's dipole;<br />
* Planck solar dipole information, used to calibrate the CMB channels;<br />
* planet models used to calibrate the Galactic channels.<br />
<br />
=== LFI inputs ===<br />
<br />
The MADAM mapmaker takes as input:<br />
* the calibrated timelines (for details see [[TOI processing LFI|TOI Processing]]);<br />
* the detector pointings (for details see [[Detector_pointing|Detector pointing]]);<br />
* the noise information in the form of 3-parameter (white noise level &sigma;, slope, and knee frequency <i>f</i><sub>knee</sub>) noise model (for details see [[The RIMO|RIMO]]).<br />
<br />
==Related products==<br />
=== Masks ===<br />
This section presents the "general purpose" masks. Other masks specific to certain products are packaged with those products.<br />
<br />
Note that for this release, HFI has not produced any new masks. <br />
<br />
==== Gatactic Centre masks ====<br />
<br />
'''TBW'''<br />
<br />
<br />
====Point source masks [TO BE REMOVED ??]====<br />
<br />
For HFI and LFI two sets of point-source masks are provided. <br />
* Intensity masks, which remove sources detected with S/N > 5. <br />
* Polarisation masks, which remove sources that have polarization detection significance levels of 99.97 % or greater at the position of a source detected in intensity. They were derived from the polarization maps with dust foreground bandpass mismatch leakage corrections applied. The area excised around each source has a radius of 3σ (width) of the beam, i.e., 1.27 FWHM (for LFI the cut around each source has a radius of 32 arcmin at 30GHz, 27 arcmin at 44 GHz, and 13 arcmin at 70 GHz).<br />
<br />
Both sets of masks are found in the files ''HFI_Mask_PointSrc_2048_R2.00.fits'' and ''LFI_Mask_PointSrc_2048_R2.00.fits'', in which the first extension contains the intensity masks, and the second contains the polarization masks.<br />
<br />
====Galactic plane masks [TO BE REMOVED ??]====<br />
<br />
Eight Galactic emission masks are provided, giving 20, 40, 60, 70, 80, 90, 97, and 99% sky coverage, derived from the 353 GHz map after CMB subtraction. These are independent of frequency channel. Three versions are given: not apodized; and apodized by 2&deg; and 5&deg;. The filenames are ''HFI_Mask_GalPlane-apoN_2048_R2.00.fits'', where <i>N</i> = 0, 2, and 5.<br />
<br />
The masks are shown below. The eight "GalPlane" masks are combined (added together) and shown in a single figure for each of the three apodizations. While the result is quite clear for the case of no apodization, it is less so for the apodized case. The "PointSrc" masks are shown separately for the intensity case.<br />
<br />
<center><br />
<gallery perrow=3 widths=260px heights=160px ><br />
File: GalPlaneMask_apo0.png | '''Galactic plane masks, no apodization.'''<br />
File: GalPlaneMask_apo2.png | '''Galactic plane masks, apodized to 2&deg;.'''<br />
File: GalPlaneMask_apo5.png | '''Galactic plane masks, apodized to 5&deg;.'''<br />
File: PointSrcMask_100.png | '''Point source mask, 100 GHz.'''<br />
File: PointSrcMask_143.png | '''Point source mask, 143 GHz.'''<br />
File: PointSrcMask_217.png | '''Point source mask, 217 GHz.'''<br />
File: PointSrcMask_353.png | '''Point source mask, 343 GHz.'''<br />
File: PointSrcMask_545.png | '''Point source mask, 545 GHz.'''<br />
File: PointSrcMask_857.png | '''Point source mask, 857 GHz.'''<br />
</gallery><br />
</center><br />
<br />
== File names ==<br />
The FITS filenames are of the form ''{H|L}FI_SkyMap_fff{-tag}_Nside_R3.nn_{coverage}-{type}.fits'', where "fff" are three digits to indicate the Planck frequency band, "tag" indicates the single detector or the detset (no "tag" indicates full channel), "Nside" is the HEALPix <i>N</i><sub>side</sub> value of the map, "coverage" indicates which part of the mission is covered (full, half mission, survey, year, etc.), and the optional "type" indicates the subset of input data used. The table below lists the products by type, with the appropriate unix wildcards that form the full filename.<br />
<br />
{| class="wikitable" align="center" style="text-align"left" border="1" cellpadding="15" cellspacing="20" width=880px<br />
|+ '''HFI FITS filenames'''<br />
|- bgcolor="ffdead"<br />
! Coverage || Filename <br />
|-<br />
| Full channel, full mission ||HFI_SkyMap_fff{-tag}_2048_R3.??_full.fits<br />
|-<br />
| Full channel, half mission || HFI_SkyMap_fff{-tag}_2048_R3.??_halfmission-{1/2}.fits<br />
|-<br />
| Full channel, full mission, odd/even ring || HFI_SkyMap_fff{-tag}_2048_R3.??_{odd/even}ring.fits <br />
|}<br />
<br />
{| class="wikitable" align="center" style="text-align"left" border="1" cellpadding="15" cellspacing="20" width=1200px<br />
|+ '''LFI FITS filenames'''<br />
|- bgcolor="ffdead"<br />
! Coverage || Filename || Half-ring filename || Comment<br />
|-<br />
| Full channel, full mission ||LFI_SkyMap_???_1024_R3.??_full.fits ||LFI_SkyMap_???_1024_R2.??_full-ringhalf-?.fits || 70GHz is corrected for Template<br />
|-<br />
| Full channel, full mission BandPass corrected ||LFI_SkyMap_???-BPassCorrected_1024_R3.??_full.fits ||LFI_SkyMap_???-BPassCorrected_???_1024_R2.??_full-ringhalf-?.fits || 70GHz is corrected for Template<br />
|-<br />
| Full channel, single survey || LFI_SkyMap_???_1024_R3.??_survey-?.fits || n/a || n/a<br />
|-<br />
| Full channel, survey combination || LFI_SkyMap_???_1024_R3.??_survey-1-3-5-6-7-8.fits || n/a || n/a<br />
|-<br />
| Full channel, survey combination BandPass corrected|| LFI_SkyMap_???_1024_R3.??-BPassCorrected_survey-1-3-5-6-7-8.fits || n/a || n/a<br />
|-<br />
| Full channel, single year || LFI_SkyMap_???_1024_R3.??_year-?.fits || n/a || n/a<br />
|-<br />
| Full channel, single year BandPass corrected|| LFI_SkyMap_???-BPassCorrected_1024_R3.??_year-?.fits || n/a || n/a<br />
|-<br />
| Full channel, year combination || LFI_SkyMap_???_1024_R3.??_year?-?.fits || n/a || n/a<br />
|-<br />
| Full channel, year combination BandPass corrected|| LFI_SkyMap_???-BPassCorrected_1024_R3.??_year?-?.fits || n/a || n/a<br />
|-<br />
| Horn pair, full mission || LFI_SkyMap_???-??-??_1024_R3.??_full.fits || LFI_SkyMap_???_??-??_1024_R3.??_full-ringhalf-?.fits || n/a<br />
|-<br />
| Single radiometer, full mission || LFI_SkyMap_???-???_1024_R3.??_full.fits || LFI_SkyMap_???-???_1024_R3.??_full-ringhalf-?.fits || n/a<br />
|}<br />
<br />
For the benefit of users who are only looking for the frequency maps with no additional information, we also provide a file combining the nine frequency maps as separate columns in a single extension. The nine columns in this file contain the intensity maps <i>only</i> and no other information (hits maps or variance maps) is provided.<br />
<br />
== FITS file structure ==<br />
<br />
The FITS files for the sky maps contain a minimal primary header with no data, and a ''BINTABLE'' extension (EXTENSION 1, EXTNAME = ''FREQ-MAP'') containing the data. The structure is shown schematically in the figure below. The ''FREQ-MAP'' extension contains a 3- or 10-column table that contain the signal, hit-count, and variance maps, all in HEALPix format. The 3-column case is for intensity only maps, while the 10-column case is for polarization. The number of rows is the number of map pixels, which is <i>N</i><sub>pix</sub> = 12 <i>N</i><sub>side</sub><sup>2</sup> for HEALPix maps, where <i>N</i><sub>side</sub> = 1024 or 2048 for most the maps presented in this section.<br />
<br />
[[File:FITS_FreqMap.png | 550px | center | thumb | '''FITS file structure.''']]<br />
<br />
Note that file sizes are approximately 0.6 GB for <i>I</i>-only maps and 1.9 GB for <i>IQU</i> maps at <i>N</i><sub>side</sub>=2048, but about 0.14 GB for <i>I</i>-only maps and 0.45 GB for <i>IQU</i> maps at <i>N</i><sub>pix</sub>=1024 .<br />
<br />
Keywords indicate the coordinate system ("GALACTIC"), the HEALPix ordering scheme ("NESTED"), the units (K<sub>CMB</sub> or MJy.sr<sup>-1</sup>) of each column, and of course the frequency channel ("FREQ"). Where polarization <i>Q</i> and <i>U</i> maps are provided, the "COSMO" polarization convention (used in HEALPix) is adopted, and it is specified in the "POLCCONV" keyword (see [[Sky_temperature_maps#Polarization_convention_used_in_the_Planck_project|this section]]). The "COMMENT" fields give a one-line summary of the product, and some other information useful for traceability within the DPCs. The original filename is also given in the "FILENAME" keyword. The "BAD_DATA" keyword gives the value used by HEALPix to indicate pixels for which no signal is present (these will also have a hit-count value of 0). The main parameters are summarized in the table below.<br />
<br />
{| border="1" cellpadding="3" cellspacing="0" align="center" style="text-align:left" width=800px<br />
|+ '''Sky map file data structure'''<br />
|- bgcolor="ffdead" <br />
!colspan="4" | 1. EXTNAME = 'FREQ-MAP' : Data columns<br />
|- bgcolor="ffdead" <br />
! Column name || Data type || Units || Description<br />
|-<br />
|I_STOKES || Real*4 || K<sub>CMB</sub> or MJy.sr<sup>-1</sup> || Stokes <i>I</i> map<br />
|-<br />
|Q_STOKES || Real*4 || K<sub>CMB</sub> or MJy.sr<sup>-1</sup> || Stokes <i>Q</i> map (optional)<br />
|-<br />
|U_STOKES || Real*4 || K<sub>CMB</sub> or MJy.sr<sup>-1</sup> || Stokes <i>U</i> map (optional)<br />
|-<br />
|HITS || Int*4 || none || The hit-count map<br />
|-<br />
|II_COV || Real*4 || K<sub>CMB</sub><sup>2</sup> or (MJy.sr<sup>-1</sup>)<sup>2</sup> || <i>II</i> variance map<br />
|-<br />
|IQ_COV || Real*4 || K<sub>CMB</sub><sup>2</sup> or (MJy.sr<sup>-1</sup>)<sup>2</sup> || <i>IQ</i> variance map (optional)<br />
|-<br />
|IU_COV || Real*4 || K<sub>CMB</sub><sup>2</sup> or (MJy.sr<sup>-1</sup>)<sup>2</sup> || <i>IQ</i> variance map (optional)<br />
|-<br />
|QQ_COV || Real*4 || K<sub>CMB</sub><sup>2</sup> or (MJy.sr<sup>-1</sup>)<sup>2</sup> || <i>QQ</i> variance map (optional)<br />
|-<br />
|QU_COV || Real*4 || K<sub>CMB</sub><sup>2</sup> or (MJy.sr<sup>-1</sup>)<sup>2</sup> || <i>QU</i> variance map (optional)<br />
|-<br />
|UU_COV || Real*4 || K<sub>CMB</sub><sup>2</sup> or (MJy.sr<sup>-1</sup>)<sup>2</sup> || <i>UU</i> variance map (optional)<br />
|-<br />
|- bgcolor="ffdead" <br />
! Keyword || Data type || Value || Description<br />
|-<br />
|PIXTYPE || String || HEALPIX ||<br />
|-<br />
|COORDSYS || String || GALACTIC ||Coordinate system <br />
|-<br />
|ORDERING || String || NESTED || Healpix ordering<br />
|-<br />
|POLCCONV || String || COSMO || Polarization convention<br />
|-<br />
|NSIDE || Int || 1024 or 2048 || HEALPix <i>N</i><sub>side</sub> <br />
|-<br />
|FIRSTPIX || Int*4 || 0 || First pixel number<br />
|-<br />
|LASTPIX || Int*4 || 12 <i>N</i><sub>side</sub><sup>2</sup> – 1 || Last pixel number<br />
|-<br />
|FREQ || String || nnn || Frequency channel <br />
|}<br />
<br />
<br />
The same structure applies to all "SkyMap" products, independent of whether they are full channel, survey of half-ring. The distinction between the types of maps is present in the FITS filename (and in the traceability comment fields).<br />
<br />
==Polarization convention used in the Planck project==<br />
<br />
The FITS keyword "POLCCONV" defines the polarization convention of the data within the file.<br />
The Planck collaboration used the COSMO convention for the polarization angle (as usually adopted in space-based and other CMB missions), whereas other subfields of astronomy usually adopt the IAU convention. The basic difference comes down to whether one thinks of the light rays being emitted from the origin (the usual mathematics/physics convention) or converging on the observer from the sky (the usual astronomy convention), and hence the "obvious" choice is different for a physicists and for an astronomer. Given that CMB results are of interest to a wide range of both physicists and astronomers, there is no single choice of convention that everyone would regard as self-evident. Hence one simply has to be aware of the convention being adopted. Because of this the Planck Collaboration has taken pains to point out which convention is being used in publications and in data releases. In the following we describe the difference between these two conventions, and the consequence if it is <i>not</i> taken into account correctly in the analysis.<br />
<br />
[[File:conventions.png|thumb|center|400px|'''Figure 1. Polarization conventions, showing the COSMO convention (left) and IAU convention (right). The vector <math>\hat{z}</math> points in the outward direction in COSMO, and inwards in IAU. The bottom panel refers to the plane tangent to the sphere.''']]<br />
<br />
Changing the orientation convention is equivalent to a transformation &psi;'=&pi;-&psi; of the polarization angle (Figure 1). The consequence of this transformation is the inversion of the Stokes parameter <i>U</i>.<br />
The components of the polarization tensor in the helicity basis <math>\epsilon^{\pm}=(\hat{x}\pm i\hat{y})/\sqrt{2}</math> are<br />
<br />
<math><br />
(Q+iU)(\hat{n}) = \sum _{\ell m}a_{2,lm}{}_{2}Y_{\ell }^{m}(\hat{n}),<br />
\\(Q-iU)(\hat{n}) = \sum _{\ell m}a_{-2,lm}{}_{2}Y_{\ell }^{m}(\hat{n}),<br />
</math><br />
<br />
where <math>{}_{2}Y_{\ell }^{m}(\hat{n})</math> are the spin-weighted spherical harmonic functions.<br />
The <i>E</i> and <i>B</i> modes can be defined as<br />
<br />
<math><br />
E(\hat{n}) = \sum_{\ell m}a_{E,\ell m}Y_{\ell }^{m}(\hat{n}),<br />
\\B(\hat{n}) = \sum_{\ell m}a_{B,\ell m}Y_{\ell }^{m}(\hat{n}),<br />
</math><br />
<br />
where the coefficients <i>a<sub>E,&#8467;m</sub></i> and <i>a<sub>B,&#8467;m</sub></i> are derived from linear combinations of the <i>a<sub>2,&#8467;m</sub></i>, <i>a<sub>-2,&#8467;m</sub></i>, defined implicitly in the first equation (<i>Q</i>&plusmn; i<i>U</i>).<br />
<br />
[[File:test_gradient.jpg|thumb|center|400px|]]<br />
[[File:test_curl.jpg|thumb|center|400px|'''Figure 2. Error on Planck-LFI 70 GHz <i>EE</i> (top) and <i>BB</i> (bottom) power spectra, in the case of an incorrect choice being made for the polarization coordinate system convention (IAU instead of COSMO).''']]<br />
<br />
The effect of the sign inversion of <i>U</i> on the polarization spectra is a non-trivial mixing of <i>E</i> and <i>B</i> modes. <br />
An example of the typical error on <i>EE</i> and <i>BB</i> auto-spectra in the case of the wrong choice for the polarization basis is shown in Figure 2.<br />
<br />
<i>One should be careful</i> to be aware of the polarization convention that is being adopted. If the IAU convention is used in computing the power spectra, then the sign of the <i>U</i> component of the Planck maps must be inverted before computing the <i>E</i> and <i>B</i> modes.<br />
<br />
In astronomical applications it is common to define a pseudo-vector <i>P</i> to show the amplitude and orientation of<br />
polarization on a map. When plotting these line segments to show the orientation of the plane of polarization (or the orthogonal direction, often considered to be the projection of the magnetic field), the results are the same for both the COSMO and IAU conventions. This because the appearance of <i>P</i> is a property of the radiation and hence not affected by the sign of <i>U</i>.<br />
<br />
=== Note on the convention used in the Planck Catalogue of Compact Sources (PCCS) ===<br />
Planck non-cosmology papers sometimes follow the IAU convention for internal analysis, for ease of comparison with other studies (e.g., comparison of Planck-derived thermal dust emission polarization with the optical polarization of starlight). Nevertheless, Planck data products, such as component-separated maps, still use the COSMO convention. The one exception is for the compact source catalogue. Because catalogues of astronomical objects found by Planck need to be compared directly with other source catalogues, the polarized sources described in the Planck Catalogue of Compact Sources follow the IAU convention, and the polarization angles are defined on an interval of [-90&deg;,90&deg;]. To switch to the COSMO convention, the polarization angles listed in the catalogue should be shifted by 90&deg; and multiplied by -1.<br />
<br />
== References ==<br />
<References /><br />
<br />
<br />
<span style="background:green"><br />
<br />
<span style="background:green"><br />
== Previous releases ==<br />
<br />
<div class="toccolours mw-collapsible mw-collapsed" style="background-color: #FFDAB9;width:80%" ><br />
'''2015 Sky temperature and polarization maps'''<br />
<br />
<div class="mw-collapsible-content"><br />
<br />
<br />
'''General description'''<br />
<br />
Sky maps give the best estimate of the intensity and polarization (Stokes Q and U components), if available, of the signal from the sky after removal, as far as possible, of known systematic effects (mostly instrumental, but including also the solar and earth-motion dipole, Galactic strylight and the Zodiacal light). Sky maps are provided for the full Planck mission using all valid detectors in each frequency channel, and also for various subsets by splitting the mission in various time ranges or in subsets of the detectors in a given channel. These products are useful for the study of source variability, but they are especially interesting for characterisation purposes (see also the [[HFI-Validation | data validation]] section). The details of the start and end of the time ranges are given in the table below.<br />
<br />
To help in further processing, there are also masks of the Galactic Plane and of point sources, each provided for several different depths.<br />
<br />
All sky maps are in Healpix format, with Nside of 1024 (LFI 30, 44 and 70) and 2048 (LFI 70 and HFI), in Galactic coordinates, and Nested ordering. <br />
<br />
;WARNING: the Healpix convention for polarization is NOT the same as the IAU convention - see Section 8 in this page.<br />
<br />
The signal is given in units of K<sub>cmb</sub> for 30-353 GHz, and of MJy/sr (for a constant <math>\nu F_\nu</math> energy distribution ) for 545 and 857 GHz. For each frequency channel, the intensity and polarization maps are packaged into a ''BINTABLE'' extension of a FITS file together with a hit-count map (or hit map, for short, giving the number of observation samples that are cumulated in a pixel, all detectors combined) and with the variance and covariance maps. Additional information is given in the FITS file header. The structure of the FITS file is given in the [[#FITS_file_structure | FITS file structure]] section below. <br />
<br />
; R2.00 : this first release (Jan 2015) contains polarisation data for the 353 GHz channel only.<br />
; R2.01 : this second release (May 2015) adds polarisation data to the 100-217 GHz channels.<br />
; R2.02 : a full re-release to correct the Healpix bad pixel value in the maps which was altered during the preparation of the maps and not reset to the correct value (the valid pixels are unchanged). It also fixes some FITS keywords, and includes a full re-release of the Zodi correction maps, with the 100-217 GHz one now including the polarisation correction)<br />
<br />
{| border="1" cellpadding="3" cellspacing="0" align="center" style="text-align:left" width=800px<br />
|+ '''Ranges for mission and surveys'''<br />
|- bgcolor="ffdead" <br />
! Range || ODs || HFI rings || pointing-IDs || Comment<br />
|-<br />
|nominal mission || 91 - 563 || 240 - 14723 || 00004200 - 03180200 ||<br />
|-<br />
|full mission || 91 - 974 || 240 - 27005 || 00004200 - 05322620 || for HFI<br />
|-<br />
|full mission || 91 - 1543 || n/a || 00004200 - 06511160 || for LFI<br />
|-<br />
|Survey 1 || 91 - 270 || 240 - 5720 || 00004200 - 01059820 ||<br />
|-<br />
|Survey 2 || 270 - 456 || 5721 - 11194 || 01059830 - 02114520 ||<br />
|-<br />
|Survey 3 || 456 - 636 || 11195 - 16691 || 02114530 - 03193660 ||<br />
|-<br />
|Survey 4 || 636 - 807 || 16692 - 21720 || 03193670 - 04243900 ||<br />
|-<br />
|Survey 5 || 807 - 974 || 21721 - 27005 || 05267180 - 05322590 || end of mission for HFI<br />
|-<br />
|Survey 5 || 807 - 993 || n/a || 05267180 - 06344800 || end of survey for LFI<br />
|-<br />
|Survey 6 || 993 - 1177 || n/a || 06344810 - 06398120 || LFI only <br />
|-<br />
|Survey 7 || 1177 - 1358 || n/a || 06398130 - 06456410 || LFI only <br />
|-<br />
|Survey 8 || 1358 - 1543 || n/a || 06456420 - 06511160 || LFI only <br />
|-<br />
|Survey 9 || 1543 - 1604 || n/a || 06511170 - 06533320 || LFI only Not in this delivery<br />
|-<br />
|HFI mission-half-1 || 91 - 531 || 240 - 13471 || 00004200 - 03155580 ||<br />
|-<br />
|HFI mission-half-2 || 531 - 974 || 13472 - 27005 || 03155590 - 05322590 ||<br />
|-<br />
|LFI Year 1 || 91 - 456 || n/a || 00004200 - 02114520 ||<br />
|-<br />
|LFI Year 2 || 456 - 807 || n/a || 02114530 - 04243900 ||<br />
|-<br />
|LFI Year 3 || 807 - 1177 || n/a || 05267180 - 06398120 ||<br />
|-<br />
|LFI Year 4 || 1177 - 1543 || n/a || 06398130 - 06511160 ||<br />
|-<br />
|}<br />
<br />
'''Production process'''<br />
<br />
Sky maps are produced by combining appropriately the data of all working detectors in a frequency channel over some period of the mission. They give the best estimate of the signal from the sky (unpolarised) after removal, as far as possible, of known systematic effects and of the dipole signals induced by the motion of the solar system in the CMB and of the Planck satellite in the solar system. In particular, they include the Zodiacal light emission (Zodi for short) and also the scattering from the far-side lobes of the beams (FSL). More on this below.<br />
<br />
''' HFI processing '''<br />
<br />
The mapmaking and calibration process is described in detail in the [[Map-making_LFI | Map-making]] section and in the {{PlanckPapers|planck2014-a09}} paper, where detailed references are found. In brief it consists of:<br />
<br />
; binning the TOI data onto ''rings'' : Healpix rings (HPRs) are used here, each ring containing the combined data of one pointing period. <br />
; flux calibration : at 100-353 GHz, the flux calibration factors are determined by correlating the signal with the orbital dipole, which is determined very accurately from the Planck satellite orbital parameters provided by Flight Dynamics. This provides a single gain factor per bolometer. At 545 and 857 GHz the gain is determined from the observation of Uranus and Neptune (but not Jupiter which is too bright) and comparison to recent models made explicitly for this mission. A single gain is applied to all rings at these frequencies.<br />
; destriping : in order to remove low-frequency noise, an offset per ring is determined by minimizing the differences between HPRs at their crossings, and removed.<br />
; Zodiacal light correction : a Zodiacal light model is used to build HPRs of the the Zodi emission, which is subtracted from the calibrated HPRs.<br />
; projection onto the map : the offset-corrected, flux-calibrated, and Zodi-cleaned HPRs are projected onto Healpix maps, with the data of each bolometer weighted by a factor of 1/NET of that bolometer.<br />
<br />
These steps are followed by some post-processing which is designed to prepare the maps for the component separation work. This post processing consists of: <br />
<br />
; Dust bandpass leakage correction : the Q and U maps are corrected for the intensity-to-polarisation leakage caused by the foregrounds having a non-CMB spectrum, and as a consequence of the non-identical bandpasses on the different detectors (bandpass mismatch, or BPM). This correction is determined using the ''ground'' method as described in Section 7.3 of {{PlanckPapers|planck2014-a09}}. These correction maps can be found in the Planck Legacy Archive as ''HFI_CorrMap_???-dustleak-ground_2048_R2.0?_{coverage}.fits''. The correction is applied by subtracting the correction map from the corresponding input map. This correction is not applied to the nominal mission maps in order to maintain compatibility with the PR1 products. ''In fact this correction was computed and applied only to the products used in component separation'', so they were not applied to the single survey maps and to the half-ring maps, which are considered characterisation products.<br />
; Far Side Lobe calibration correction : the 100-217 maps are multiplied by factors of 1.00087, 1.00046, and 1.00043, respectively, to compensate for the non-removal of the far-side lobes, and similarly the corresponding covariance maps have also been corrected by multiplication by the square of the factor.<br />
; Fill missing pixels : missing pixels are filled in with a value that is the mean of valid pixels within a given radius. A radius of 1 deg is used for the full channel maps, and 1.5 deg is used for the detset maps. This step is not applied to the single survey maps since they have large swaths of the sky that are not covered.<br />
<br />
; Map zero-level : for the 100 to 857 GHz maps, the zero levels are set to their optimal levels for Galactic and CIB studies. A procedure for adjusting them to astrophysical values is given in the HFI Mapmaking and Calibration paper {{PlanckPapers|planck2014-a09}}.<br />
<br />
These maps provide the main mission products. Together with signal maps, hit count, variance, and variance maps are also produced. The hit maps give the (integer) number of valid TOI-level samples that contribute to the signal of each pixel. All valid samples are counted in the same way, i.e., there is no weighting factor applied. The variance maps project the white noise estimate, provided by the NETs, in the sky domain.<br />
<br />
Note that the nominal mission maps have not had the post-processing applied, which makes them more easily comparable to the PR1 products.<br />
<br />
''' LFI processing '''<br />
LFI maps were constructed with the Madam map-making code, version 3.7.4. The code is based on generalized destriping technique, where the correlated noise component is modeled as a sequence of constant offset, called baselines. A noise filter was used to constrain the baseline solution allowing the use of 0.25 s and 1 second baselines for the 30 and 44, 70 GHz respectively.<br />
<br />
Radiometers were combined according to the horn-uniform weighting scheme to minimize systematics. The used weights are listed in [[Map-making LFI#Map-making|Map-making]]. The flagged samples were excluded from the analysis by setting their weights to <math>C_{w}^{-1}</math> = 0. The galaxy region was masked out in the destriping phase, to reduce error arising from strong signal gradients. The polarization component was included in the analysis... <br />
<br />
; Dipole and Far Side Lobe correction : input timelines are cleaned by 4pi convolved dipole and Galactic Straylight obtained as convolution of the 4pi in band far sidelobes and Galactic Simulation as explained in Section 7.4 of {{PlanckPapers|planck2014-a03}}. <br />
<br />
Beam effects on the LFI maps are described in Section 7.1 of {{PlanckPapers|planck2014-a03}}. Scaling of the maps due to beam effects is taken into account in the LFI's beam functions (as provided in the RIMO, give reference) which should be used for analysis of diffuse components. To compute the flux densities of compact sources, correction must be made for beam effects (see Table 8 of {{PlanckPapers|planck2014-a03}})."<br />
<br />
; Bandpass leakage correction : '''as opposed to the HFI, the LFI high resolution maps have not been corrected for bandpass leakage. Only low resolution (nside 256) maps are provided with the bandpass correction'''. The correction maps (LFI_CorrMap_0??-BPassCorr_*.fits) can be found in the Planck Legacy Archive. Further details about the procedure used to generate the bandpass correction maps can be found in Section 11 of {{PlanckPapers|planck2014-a03}}.<br />
<br />
; Map zero-level : for the 30, 44 and 70 GHz, maps are corrected for zero level monopole by applying an offset correction, see LFI Calibration paper {{PlanckPapers|planck2014-a06}}. Note that the offset applied is indicated in the header as a comment keyword.<br />
<br />
A detailed description of the map-making procedure is given in {{PlanckPapers|planck2013-p02}}, {{PlanckPapers|planck2014-a03}}, {{PlanckPapers|planck2014-a07}} and in section [[Map-making LFI#Map-making|Map-making]].<br />
<br />
'''Types of maps '''<br />
<br />
''' Full mission, full channel maps (6 HFI, 4 LFI)'''<br />
<br />
Full channel maps are built using all the valid detectors of a frequency channel and cover the either the full or the nominal mission. For HFI, the 143-8 and 545-3 bolometers are rejected entirely as they are seriously affected by RTS noise. HFI provides the Q and U components for the 100, 143, 217 and 353 GHz channels only. LFI provides the I, Q and U maps for all the channels. Reminder: HFI Q and U maps are corrected for bandpass leakage but LFI Q and U maps are not. The I, Q and U maps are displayed in the figures below. The color range is set using a histogram equalisation scheme (from HEALPIX) that is useful for these non-Gaussian data fields. For visualization purposes, the Q and U maps shown here have been smoothed with a 1 degree Gaussian kernel, otherwise they look like noise to the naked eye.<br />
The 70 GHz full map is available also at <math>N_{side}</math> 2048.<br />
<br />
<center><br />
<gallery style="padding:0 0 0 0;" perrow=3 widths=260px heights=160px> <br />
File: SkyMap30e.png| '''Full mission I, 30 GHz'''<br />
File: SkyMap44e.png | '''Full mission I, 44 GHz'''<br />
File: SkyMap70e.png | '''Full mission I, 70 GHz'''<br />
File: SkyMap100e.png | '''Full mission I, 100 GHz'''<br />
File: SkyMap143e.png | '''Full mission I, 143 GHz'''<br />
File: SkyMap217e.png | '''Full mission I, 217 GHz'''<br />
File: SkyMap353e.png | '''Full mission I, 353 GHz'''<br />
File: SkyMap545e.png | '''Full mission I, 545 GHz'''<br />
File: SkyMap857e.png | '''Full mission I, 857 GHz'''<br />
</gallery><br />
</center><br />
<br><br />
<center><br />
<gallery style="padding:0 0 0 0;" perrow=3 widths=260px heights=160px> <br />
File: LFI_SkyMap_030_1024_R2.01_full_Qb_sm1deg.png| '''Full mission Q, 30 GHz'''<br />
File: LFI_SkyMap_044_1024_R2.01_full_Qb_sm1deg.png | '''Full mission Q, 44 GHz'''<br />
File: LFI_SkyMap_070_1024_R2.01_full_Qb_sm1deg.png | '''Full mission Q, 70 GHz'''<br />
File: HFI_Skymap_100_full_bplcorrected_sm1deg_Qb.png | '''Full mission Q, 100 GHz'''<br />
File: HFI_Skymap_143_full_bplcorrected_sm1deg_Qb.png | '''Full mission Q, 143 GHz'''<br />
File: HFI_Skymap_217_full_bplcorrected_sm1deg_Qb.png | '''Full mission Q, 217 GHz'''<br />
File: HFI_Skymap_353_full_bplcorrected_sm1deg_Qb.png | '''Full mission Q, 353 GHz'''<br />
</gallery><br />
</center><br />
<br><br />
<center><br />
<gallery style="padding:0 0 0 0;" perrow=3 widths=260px heights=160px> <br />
File: LFI_SkyMap_030_1024_R2.01_full_Ub_sm1deg.png| '''Full mission U, 30 GHz'''<br />
File: LFI_SkyMap_044_1024_R2.01_full_Ub_sm1deg.png | '''Full mission U, 44 GHz'''<br />
File: LFI_SkyMap_070_1024_R2.01_full_Ub_sm1deg.png | '''Full mission U, 70 GHz'''<br />
File: HFI_Skymap_100_full_bplcorrected_sm1deg_Ub.png | '''Full mission U, 100 GHz'''<br />
File: HFI_Skymap_143_full_bplcorrected_sm1deg_Ub.png | '''Full mission U, 143 GHz'''<br />
File: HFI_Skymap_217_full_bplcorrected_sm1deg_Ub.png | '''Full mission U, 217 GHz'''<br />
File: HFI_Skymap_353_full_bplcorrected_sm1deg_Ub.png | '''Full mission U, 353 GHz'''<br />
</gallery><br />
<br />
</center><br />
<br />
''' Full mission light maps, full channel maps (6 HFI, 7 LFI) '''<br />
<br />
These maps are based on the Full mission maps but contain fewer columns, IQU from 30 to 353 GHz, and I only at 545 and 857 GHz. These maps have been produced to reduce the transfer time of the most downloaded frequency full mission maps.<br />
<br />
''' Nominal mission, full channel maps (6 HFI) '''<br />
<br />
These maps are similar to the ones above, but cover the nominal mission only. They are meant primarily to be compared to the PR1 products in order to see the level of improvements in the processing. Because of this, they are produced in Temperature only, and have not had the post-processing applied.<br />
<br />
''' Single survey, full channel maps (30 HFI, 35 LFI)'''<br />
<br />
Single survey maps are built using all valid detectors of a frequency channel; they cover separately the different sky surveys. The surveys are defined as the times over which the satellite spin axis rotates but 180 degrees, which, due to the position of the detectors in the focal plane does not cover the full sky, but a fraction between ~80 and 90% depending on detector position. During adjacent surveys the sky is scanned in opposite directions. More precisely it is the ecliptic equator that is scanned in opposite directions. While these are useful to investigate variable sources, they are also used to study the systematics of the time-response of the detectors as they scan bright sources, like the Galactic Plane, in different directions during different survey. Note that the HFI and LFI missions cover 5 and 8 surveys, respectively, and in case of HFI the last survey in incomplete.<br />
The 70 GHz surveys maps are available also at <math>N_{side}</math> 2048.<br />
Note LFI provide a special surveys maps combination used in the low l analysis. This maps, available at the three LFI frequency 30, 44 and 70 GHz, was built using the combination of survey 1, 3, 5, 6, 7 and 8. <br />
<br />
''' Year maps, full channel maps (12 HFI, 16 LFI)'''<br />
<br />
These maps are built using the data of surveys 1+2, surveys 3+4, and so forth. They are used to study long-term systematic effects.<br />
The 70 GHz years maps are available also at <math>N_{side}</math> 2048.<br />
<br />
'''Half-mission maps, full channel maps (12 HFI, 12 LFI)'''<br />
<br />
For HFI, the half mission is defined after eliminating those rings discarded for all bolometers. There are 347 such rings, may of which are during the 5th survey when the ''End-of-Life'' tests were performed. The remaining 26419 rings are divided in half (up to the odd ring) to define the two halves of the mission. This exercise is done for the full mission only.<br />
<br />
For LFI instead of the half-mission the following year combination has been created: Year 1+2, Year 1+3, Year 2+4, Year 3+4, <br />
<br />
'''Full mission, single detector maps (18 HFI, 22 LFI)'''<br />
<br />
IN case of HFI these maps are built only for the SWBs (non polarized) and contain only temperature data, of course. They are not built for the polarisation sensitive detectors because they are not fixed on the sky as the polarisation component depends on the position angle at the time of observation. Instead, we provide maps built by ''quads'' of polarisation-sensitive detectors (see next section), which have different polarisation angles and that can be used to built I, Q, and U maps<br />
<br />
{| border="1" cellpadding="3" cellspacing="0" align="center" style="text-align:left" width=600px<br />
|+ '''HFI Temperature sensitive bolometers'''<br />
|- bgcolor="ffdead" <br />
!Frequency || Detector names<br />
|-<br />
|143 GHz || 143-5, 6, 7<br />
|-<br />
|217 GHz || 217-1, 2, 3, 4<br />
|-<br />
|353 GHz || 353-1, 2, 7, 8<br />
|-<br />
|545 GHz || 545-1, 2, 4<br />
|-<br />
|857 GHz || 857-1, 2 , 3, 4<br />
|}<br />
<br />
The 143-8 and 353-3 bolometer data are affected by strong RTS (random telegraphic signal) noise. They have not been used in the data processing, and are not delivered. For a figure showing the focal plane layout, see [[Detector_pointing#Introduction_and_Summary | this Introduction]] of the Detector Pointing chapter.<br />
<br />
In case of LFI, all the 22 Radiometers maps are available, those, obviously, are only in temperature.<br />
<br />
'''Full mission, detector set or detector pairs maps (8 HFI, 8 LFI)'''<br />
<br />
The objective here is to build independent temperature (I) and polarisation (Q and U) maps with the two pairs of polarisation sensitive detectors of each channel where they are available, i.e. in the 44-353 GHz channels. The table below indicates which detectors were used to built each detector set (detset).<br />
<br />
<br />
{| border="1" cellpadding="3" cellspacing="0" align="center" style="text-align:left" width=600px<br />
|+ '''Definition of HFI Detector Sets'''<br />
|- bgcolor="ffdead" <br />
!Frequency || DetSet1 || DetSet2 <br />
|-<br />
|100 GHz || 100-1a/b & 100-4a/b || 100-2a/b & 100-3a/b<br />
|-<br />
|143 GHz || 143-1a/b 1 & 43-3a/b || 143-2a/b & 143-4a/b<br />
|-<br />
|217 GHz || 217-5a/b & 217-7a/b || 217-6a/b & 217-8a/b<br />
|-<br />
|353 GHz || 353-3a/b & 353-5a/b || 353-4a/b & 353-6a/b<br />
|}<br />
<br />
{| border="1" cellpadding="3" cellspacing="0" align="center" style="text-align:left" width=600px<br />
|+ '''Definition of LFI Detector Pairs'''<br />
|- bgcolor="ffdead" <br />
!Frequency || Horn Pair || Comment <br />
|-<br />
|44 GHz || 24 || This maps is only in temperature<br />
|-<br />
|44 GHz || 25 & 26 || <br />
|-<br />
|70 GHz || 18 & 23 || Available also at <math>N_{side}</math> = 2048<br />
|-<br />
|70 GHz || 19 & 22 || Available also at <math>N_{side}</math> = 2048<br />
|-<br />
|70 GHz || 20 & 21 || Available also at <math>N_{side}</math> = 2048<br />
|}<br />
<br />
<br />
'''Half-ring maps (64 HFI, 62 LFI)'''<br />
<br />
These maps are similar to the ones above, but are built using only the first or the second half of each ring (or pointing period). The HFI provides half-ring maps for the full mission only, and for the full channel, the detsets, and the single bolometers. The LFI provides half-rings maps for the channel full mission (70 GHz also at <math>N_{side}</math> 2048), for the radiometer full mission and the horn pairs full mission.<br />
<!----<br />
'''Masks'''<br />
<br />
Masks are provided of the Galactic Plane and of the point sources. For the Galactic Plane, eight masks are given covering different fractions of the sky, and for the points sources two masks are given, at the 5 and 10 sigma level, for each Planck HFI and LFI frequency channel. These are generic masks, specific masks applicable to other products are delivered with the products themselves.<br />
---><br />
<br />
''' The Zodiacal light correction maps '''<br />
<br />
The Zodiacal light signal depends on the location of the observer relative to the Zodiacal light bands, and thus it is not a fixed pattern on the sky but depends on the period of observation. The maps presented here are the difference between the uncorrected (and not delivered) and the corrected maps. <br />
<br />
Note that while the Zodiacal light model that is subtracted at ring level (see [[Map-making#Zodiacal_light_correction | here]]) is not polarised, the corrections are not null and Q and U. This is suspected to come from some combination of leakage due to bandpass differences and beam mismatch, and maybe other effects. These leakages are typically of order a few %, at max, of the maximum zodi intensity at I for each channel. They range from ~150 nK at 100 GHz to ~5 uK at 353 GHz.<br />
<br />
''' Caveats and known issues '''<br />
<br />
; HFI polarization 100-217 GHz : at low multipoles, despite the progress that has been made to control the systematic effects present in the maps, polarization data between 100-217 GHz are still contaminated by systematic residuals. Figure 10 of {{PlanckPapers|planck2014-a09}} shows the EE power spectra from the half-difference maps at 100, 143, and 217 GHz and compared to the noise power spectrum from FFP8 simulations. he half-ring differences are compatible with noise while, at multipoles typically lower than 50, detector-set and half-mission differences are dominated by excess power which is larger than the EE CMB signal. The Planck Collaboration has used the range ell>30 to carry out component separation ({{PlanckPapers|planck2014-a11}}), as data at ell<30 is not considered usable for cosmological analyses. The origin of the excess power will be explored in a forthcoming publication.<br />
<br />
<br />
'''Inputs'''<br />
''' HFI inputs '''<br />
<br />
The HFI mapmaking takes as input:<br />
* the cleaned TOIs of signal of each detector, together with their flags, produced by the [[TOI processing|TOI processing]] pipeline;<br />
* the TOIs of pointing (quaternions), described in [[Detector_pointing|Detector pointing]];<br />
* bolometer-level characterization data, from the DPC's internal IMO (not distributed);<br />
* Planck orbit data, used to compute and remove the Earth's dipole;<br />
* Planck solar dipole information, used to calibrate the CMB channels;<br />
* Planet models used to calibrate the Galactic channels.<br />
<br />
''' LFI inputs '''<br />
<br />
The Madam mapmaker takes as input:<br />
<br />
* the calibrated timelines (for details see [[TOI processing LFI|TOI Processing]]);<br />
* the detector pointings (for details see [[Detector_pointing|Detector pointing]]);<br />
* the noise information in the form of 3-parameter (white noise level, &sigma;, slope, and knee frequency, <i>f</i><sub>knee</sub>) noise model (for details see [[The RIMO|RIMO]])<br />
<br />
'''Related products'''<br />
''' Masks '''<br />
<br />
This section presents the masks of the point sources and of the Galactic plane. These are ''general purpose'' masks. Other masks specific to certain products are packaged with the products.<br />
<br />
'''Point source masks'''<br />
<br />
For HFI and LFI two sets of masks are provided: <br />
* Intensity masks, which removes sources detected with SNR > 5. <br />
* Polarisation masks, which remove sources which have polarisation detection significance of 99.97 % or greater at the position of a source detected in intensity. They were derived from the polarisation maps with dust ground bandpass mismatch leakage correction applied. The cut around each source has a radius of 3σ (width) of the beam ~ 1.27 FWHM (for LFI the cut around each source has a radius of 32 arcmin at 30GHz, 27 arcmin at 44 GHz and 13 arcmin at 70 GHz).<br />
<br />
Both sets are found in the files ''HFI_Mask_PointSrc_2048_R2.00.fits'' and ''LFI_Mask_PointSrc_2048_R2.00.fits'' in which the first extension contains the Intensity masks, and the second contains the Polarisation masks.<br />
<br />
'''Galactic plane masks'''<br />
<br />
Eight masks are provided giving 20, 40, 60, 70, 80, 90, 97, and 99% sky coverage derived from the 353 GHz map, after CMB subtraction. They are independent of frequency channel. Three versions of these are given: not apodized, and apodized by 2 and 5 deg. The filenames are ''HFI_Mask_GalPlane-apoN_2048_R2.00.fits'', where N = 0, 2, 5.<br />
<br />
The masks are shows below. The 8 GalPlane masks are combined (added together) and shown in a single figure for each of the three apodization. While the result is quite clear for the case of no apodization, it is less so for the apodized case. The point source masks are shown separately for the Intensity case.<br />
<br />
<center><br />
<gallery perrow=3 widths=260px heights=160px ><br />
File: GalPlaneMask_apo0.png | '''Galactic Plane masks, no apod'''<br />
File: GalPlaneMask_apo2.png | '''Galactic Plane masks, apod 2 deg'''<br />
File: GalPlaneMask_apo5.png | '''Galactic Plane masks, apod 5 deg'''<br />
File: PointSrcMask_100.png | '''PointSource mask 100 GHz'''<br />
File: PointSrcMask_143.png | '''PointSource mask 143 GHz'''<br />
File: PointSrcMask_217.png | '''PointSource mask 217 GHz'''<br />
File: PointSrcMask_353.png | '''PointSource mask 343 GHz'''<br />
File: PointSrcMask_545.png | '''PointSource mask 545 GHz'''<br />
File: PointSrcMask_857.png | '''PointSource mask 857 GHz'''<br />
</gallery><br />
</center><br />
<br />
''' File names '''<br />
The FITS filenames are of the form ''{H|L}FI_SkyMap_fff{-tag}_Nside_R2.nn_{coverage}-{type}.fits'', where ''fff'' are three digits to indicate the Planck frequency band, ''tag'' indicates the single detector or the detset, ''Nside'' is the Healpix Nside of the map, ''coverage'' indicates which part of the mission is covered (full, half mission, survey, year, ...) , and the optional ''type'' indicates the subset of input data used. The table below lists the products by type, with the appropriate unix wildcards that form the full filename.<br />
<br />
{| class="wikitable" align="center" style="text-align"left" border="1" cellpadding="15" cellspacing="20" width=880px<br />
|+ '''HFI FITS filenames'''<br />
|- bgcolor="ffdead"<br />
! Coverage || filename || half-ring filename <br />
|-<br />
| Full chan, full mission ||HFI_SkyMap_???_2048_R2.??_full.fits ||HFI_SkyMap_???_2048_R2.??_full-ringhalf-?.fits<br />
|-<br />
| Full channel, nominal mission ||HFI_SkyMap_???_2048_R2.??_nominal.fits || n/a<br />
|-<br />
| Full channel, single survey || HFI_SkyMap_???_2048_R2.??_survey-?.fits || n/a<br />
|-<br />
| Full channel, single year || HFI_SkyMap_???_2048_R2.??_year-?.fits || n/a<br />
|-<br />
| Full channel, half mission || HFI_SkyMap_???_2048_R2.??_halfmission*-?.fits || n/a<br />
|-<br />
| Det-set, full mission || HFI_SkyMap_???-ds?_2048_R2.??_full.fits || HFI_SkyMap_???-ds?_2048_R2.??_full-ringhalf-?.fits<br />
|-<br />
|Single SWB, full mission || HFI_SkyMap_???-?_2048_R2.??_full.fits || HFI_SkyMap_???-?_2048_R2.??_full-ringhalf-?.fits<br />
|}<br />
<br />
{| class="wikitable" align="center" style="text-align"left" border="1" cellpadding="15" cellspacing="20" width=1000px<br />
|+ '''LFI FITS filenames'''<br />
|- bgcolor="ffdead"<br />
! Coverage || filename || half-ring filename || Comment<br />
|-<br />
| Full channel, full mission ||LFI_SkyMap_???_1024_R2.??_full.fits ||LFI_SkyMap_???_1024_R2.??_full-ringhalf-?.fits || Available also at Nside = 2048<br />
|-<br />
| Full channel, single survey || LFI_SkyMap_???_1024_R2.??_survey-?.fits || n/a || Available also at Nside = 2048<br />
|-<br />
| Full channel, survey combination || LFI_SkyMap_???_1024_R2.??_survey-1-3-5-6-7-8.fits || n/a || n/a<br />
|-<br />
| Full channel, single year || LFI_SkyMap_???_1024_R2.??_year-?.fits || n/a || Available also at Nside = 2048<br />
|-<br />
| Full channel, year combination || LFI_SkyMap_???_1024_R2.??_year?-?.fits || n/a || n/a<br />
|-<br />
| Horn pair, full mission || LFI_SkyMap_???-??-??_1024_R2.??_full.fits || LFI_SkyMap_???_??-??_1024_R2.??_full-ringhalf-?.fits || Available also at Nside = 2048<br />
|-<br />
| Single radiometer, full mission || LFI_SkyMap_???-???_1024_R2.??_full.fits || LFI_SkyMap_???-???_1024_R2.??_full-ringhalf-?.fits || n/a<br />
|}<br />
<br />
<br />
<br />
For the benefit of users who are only looking for the frequency maps with no additional information, we also provide a file combining the 9 frequency maps as separate columns in a single extension. The 9 columns in this file contain the intensity maps ONLY and no other information (hit maps and variance maps) is provided.<br />
<br />
<!---<br />
{| class="wikitable" align="center" style="text-align:center" border="1" cellpadding="3" cellspacing="0" width=500px<br />
|+ '''FITS filenames'''<br />
|- bgcolor="ffdead"<br />
! Frequency || Full channel maps<br />
|-<br />
| '''30GHz''' || {{PLASingleFile|fileType=map|name=LFI_SkyMap_030_1024_R1.10_nominal.fits|link=LFI_SkyMap_030_1024_R1.10_nominal.fits}}<br />
|-<br />
| '''44GHz''' || {{PLASingleFile|fileType=map|name=LFI_SkyMap_044_1024_R1.10_nominal.fits|link=LFI_SkyMap_044_1024_R1.10_nominal.fits}}<br />
|-<br />
| '''70GHz''' || {{PLASingleFile|fileType=map|name=LFI_SkyMap_070_1024_R1.10_nominal.fits|link=LFI_SkyMap_070_1024_R1.10_nominal.fits}}<br />
|-<br />
| '''70GHz''' || {{PLASingleFile|fileType=map|name=LFI_SkyMap_070_2048_R1.10_nominal.fits|link=LFI_SkyMap_070_2048_R1.10_nominal.fits}}<br />
|-<br />
| '''100GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_100_2048_R1.10_nominal.fits|link=HFI_SkyMap_100_2048_R1.10_nominal.fits}}<br />
|-<br />
| '''143GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_143_2048_R1.10_nominal.fits|link=HFI_SkyMap_143_2048_R1.10_nominal.fits}}<br />
|-<br />
| '''217GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_217_2048_R1.10_nominal.fits|link=HFI_SkyMap_217_2048_R1.10_nominal.fits}}<br />
|-<br />
| '''353GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_353_2048_R1.10_nominal.fits|link=HFI_SkyMap_353_2048_R1.10_nominal.fits}}<br />
|-<br />
| '''545GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_545_2048_R1.10_nominal.fits|link=HFI_SkyMap_545_2048_R1.10_nominal.fits}}<br />
|-<br />
| '''857GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_857_2048_R1.10_nominal.fits|link=HFI_SkyMap_857_2048_R1.10_nominal.fits}}<br />
|- bgcolor="ffdead"<br />
! Frequency || Full channel, Zodi-corrected maps<br />
|-<br />
| '''100GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_100_2048_R1.10_nominal_ZodiCorrected.fits|link=HFI_SkyMap_100_2048_R1.10_nominal_ZodiCorrected.fits}} <br />
|-<br />
| '''143GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_143_2048_R1.10_nominal_ZodiCorrected.fits|link=HFI_SkyMap_143_2048_R1.10_nominal_ZodiCorrected.fits}}<br />
|-<br />
| '''217GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_217_2048_R1.10_nominal_ZodiCorrected.fits|link=HFI_SkyMap_217_2048_R1.10_nominal_ZodiCorrected.fits}}<br />
|-<br />
| '''353GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_353_2048_R1.10_nominal_ZodiCorrected.fits|link=HFI_SkyMap_353_2048_R1.10_nominal_ZodiCorrected.fits}}<br />
|-<br />
| '''545GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_545_2048_R1.10_nominal_ZodiCorrected.fits|link=HFI_SkyMap_545_2048_R1.10_nominal_ZodiCorrected.fits}}<br />
|-<br />
| '''857GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_857_2048_R1.10_nominal_ZodiCorrected.fits|link=HFI_SkyMap_857_2048_R1.10_nominal_ZodiCorrected.fits}}<br />
|- bgcolor="ffdead"<br />
! Frequency || Combined frequency maps<br />
|-<br />
| '''All''' || {{PLASingleFile|fileType=file|name=COM_MapSet_I-allFreqs_R1.10_nominal.fits|link=COM_MapSet_I-allFreqs_R1.10_nominal.fits}} <br />
|}<br />
<br />
<br />
{| class="wikitable" align="center" style="text-align:center" border="1" cellpadding="3" cellspacing="0" width=850px<br />
|+ '''FITS filenames'''<br />
|- bgcolor="ffdead"<br />
! Frequency || Survey 1 maps || Survey 2 maps<br />
|-<br />
| '''30GHz''' || {{PLASingleFile|fileType=map|name=LFI_SkyMap_030_1024_R1.10_survey_1.fits|link=LFI_SkyMap_030_1024_R1.10_survey_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=LFI_SkyMap_030_1024_R1.10_survey_2.fits|link=LFI_SkyMap_030_1024_R1.10_survey_2.fits}}<br />
|-<br />
| '''44GHz''' || {{PLASingleFile|fileType=map|name=LFI_SkyMap_044_1024_R1.10_survey_1.fits|link=LFI_SkyMap_044_1024_R1.10_survey_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=LFI_SkyMap_044_1024_R1.10_survey_2.fits|link=LFI_SkyMap_044_1024_R1.10_survey_2.fits}}<br />
|-<br />
| '''70GHz''' || {{PLASingleFile|fileType=map|name=LFI_SkyMap_070_1024_R1.10_survey_1.fits|link=LFI_SkyMap_070_1024_R1.10_survey_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=LFI_SkyMap_070_1024_R1.10_survey_2.fits|link=LFI_SkyMap_070_1024_R1.10_survey_2.fits}}<br />
|-<br />
| '''70GHz''' || {{PLASingleFile|fileType=map|name=LFI_SkyMap_070_2048_R1.10_survey_1.fits|link=LFI_SkyMap_070_2048_R1.10_survey_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=LFI_SkyMap_070_2048_R1.10_survey_2.fits|link=LFI_SkyMap_070_2048_R1.10_survey_2.fits}}<br />
|-<br />
| '''100GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_100_2048_R1.10_survey_1.fits|link=HFI_SkyMap_100_2048_R1.10_survey_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_100_2048_R1.10_survey_2.fits|link=HFI_SkyMap_100_2048_R1.10_survey_2.fits}}<br />
|-<br />
| '''143GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_143_2048_R1.10_survey_1.fits|link=HFI_SkyMap_143_2048_R1.10_survey_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_143_2048_R1.10_survey_2.fits|link=HFI_SkyMap_143_2048_R1.10_survey_2.fits}}<br />
|-<br />
| '''217GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_217_2048_R1.10_survey_1.fits|link=HFI_SkyMap_217_2048_R1.10_survey_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_217_2048_R1.10_survey_2.fits|link=HFI_SkyMap_217_2048_R1.10_survey_2.fits}}<br />
|-<br />
| '''353GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_353_2048_R1.10_survey_1.fits|link=HFI_SkyMap_353_2048_R1.10_survey_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_353_2048_R1.10_survey_2.fits|link=HFI_SkyMap_353_2048_R1.10_survey_2.fits}}<br />
|-<br />
| '''545GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_545_2048_R1.10_survey_1.fits|link=HFI_SkyMap_545_2048_R1.10_survey_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_545_2048_R1.10_survey_2.fits|link=HFI_SkyMap_545_2048_R1.10_survey_2.fits}}<br />
|-<br />
| '''857GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_857_2048_R1.10_survey_1.fits|link=HFI_SkyMap_857_2048_R1.10_survey_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_857_2048_R1.10_survey_2.fits|link=HFI_SkyMap_857_2048_R1.10_survey_2.fits}}<br />
|- bgcolor="ffdead"<br />
! Frequency || Survey 1 Zodi-corrected maps || Survey 2 Zodi-corrected maps<br />
|-<br />
| '''100GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_100_2048_R1.10_survey_1_ZodiCorrected.fits|link=HFI_SkyMap_100_2048_R1.10_survey_1_ZodiCorrected.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_100_2048_R1.10_survey_2_ZodiCorrected.fits|link=HFI_SkyMap_100_2048_R1.10_survey_2_ZodiCorrected.fits}}<br />
|-<br />
| '''143GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_143_2048_R1.10_survey_1_ZodiCorrected.fits|link=HFI_SkyMap_143_2048_R1.10_survey_1_ZodiCorrected.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_143_2048_R1.10_survey_2_ZodiCorrected.fits|link=HFI_SkyMap_143_2048_R1.10_survey_2_ZodiCorrected.fits}}<br />
|-<br />
| '''217GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_217_2048_R1.10_survey_1_ZodiCorrected.fits|link=HFI_SkyMap_217_2048_R1.10_survey_1_ZodiCorrected.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_217_2048_R1.10_survey_2_ZodiCorrected.fits|link=HFI_SkyMap_217_2048_R1.10_survey_2_ZodiCorrected.fits}}<br />
|-<br />
| '''353GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_353_2048_R1.10_survey_1_ZodiCorrected.fits|link=HFI_SkyMap_353_2048_R1.10_survey_1_ZodiCorrected.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_353_2048_R1.10_survey_2_ZodiCorrected.fits|link=HFI_SkyMap_353_2048_R1.10_survey_2_ZodiCorrected.fits}}<br />
|-<br />
| '''545GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_545_2048_R1.10_survey_1_ZodiCorrected.fits|link=HFI_SkyMap_545_2048_R1.10_survey_1_ZodiCorrected.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_545_2048_R1.10_survey_2_ZodiCorrected.fits|link=HFI_SkyMap_545_2048_R1.10_survey_2_ZodiCorrected.fits}}<br />
|-<br />
| '''857GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_857_2048_R1.10_survey_1_ZodiCorrected.fits|link=HFI_SkyMap_857_2048_R1.10_survey_1_ZodiCorrected.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_857_2048_R1.10_survey_2_ZodiCorrected.fits|link=HFI_SkyMap_857_2048_R1.10_survey_2_ZodiCorrected.fits}}<br />
|- bgcolor="ffdead"<br />
! Frequency || Half-ring 1 maps ||Half-ring 2 maps<br />
|-<br />
| '''30GHz''' || {{PLASingleFile|fileType=map|name=LFI_SkyMap_030_1024_R1.10_nominal_ringhalf_1.fits|link=LFI_SkyMap_030_1024_R1.10_nominal_ringhalf_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=LFI_SkyMap_030_1024_R1.10_nominal_ringhalf_2.fits|link=LFI_SkyMap_030_1024_R1.10_nominal_ringhalf_2.fits}}<br />
|-<br />
| '''44GHz''' || {{PLASingleFile|fileType=map|name=LFI_SkyMap_044_1024_R1.10_nominal_ringhalf_1.fits|link=LFI_SkyMap_044_1024_R1.10_nominal_ringhalf_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=LFI_SkyMap_044_1024_R1.10_nominal_ringhalf_2.fits|link=LFI_SkyMap_044_1024_R1.10_nominal_ringhalf_2.fits}}<br />
|-<br />
| '''70GHz''' || {{PLASingleFile|fileType=map|name=LFI_SkyMap_070_1024_R1.10_nominal_ringhalf_1.fits|link=LFI_SkyMap_070_1024_R1.10_nominal_ringhalf_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=LFI_SkyMap_070_1024_R1.10_nominal_ringhalf_2.fits|link=LFI_SkyMap_070_1024_R1.10_nominal_ringhalf_2.fits}}<br />
|-<br />
| '''70GHz''' || {{PLASingleFile|fileType=map|name=LFI_SkyMap_070_2048_R1.10_nominal_ringhalf_1.fits|link=LFI_SkyMap_070_2048_R1.10_nominal_ringhalf_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=LFI_SkyMap_070_2048_R1.10_nominal_ringhalf_2.fits|link=LFI_SkyMap_070_2048_R1.10_nominal_ringhalf_2.fits}}<br />
|-<br />
| '''100GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_100_2048_R1.10_nominal_ringhalf_1.fits|link=HFI_SkyMap_100_2048_R1.10_nominal_ringhalf_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_100_2048_R1.10_nominal_ringhalf_2.fits|link=HFI_SkyMap_100_2048_R1.10_nominal_ringhalf_2.fits}}<br />
|-<br />
| '''143GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_143_2048_R1.10_nominal_ringhalf_1.fits|link=HFI_SkyMap_143_2048_R1.10_nominal_ringhalf_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_143_2048_R1.10_nominal_ringhalf_2.fits|link=HFI_SkyMap_143_2048_R1.10_nominal_ringhalf_2.fits}}<br />
|-<br />
| '''217GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_217_2048_R1.10_nominal_ringhalf_1.fits|link=HFI_SkyMap_217_2048_R1.10_nominal_ringhalf_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_217_2048_R1.10_nominal_ringhalf_2.fits|link=HFI_SkyMap_217_2048_R1.10_nominal_ringhalf_2.fits}}<br />
|-<br />
| '''353GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_353_2048_R1.10_nominal_ringhalf_1.fits|link=HFI_SkyMap_353_2048_R1.10_nominal_ringhalf_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_353_2048_R1.10_nominal_ringhalf_2.fits|link=HFI_SkyMap_353_2048_R1.10_nominal_ringhalf_2.fits}}<br />
|-<br />
| '''545GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_545_2048_R1.10_nominal_ringhalf_1.fits|link=HFI_SkyMap_545_2048_R1.10_nominal_ringhalf_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_545_2048_R1.10_nominal_ringhalf_2.fits|link=HFI_SkyMap_545_2048_R1.10_nominal_ringhalf_2.fits}}<br />
|-<br />
| '''857GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_857_2048_R1.10_nominal_ringhalf_1.fits|link=HFI_SkyMap_857_2048_R1.10_nominal_ringhalf_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_857_2048_R1.10_nominal_ringhalf_2.fits|link=HFI_SkyMap_857_2048_R1.10_nominal_ringhalf_2.fits}}<br />
|}<br />
---><br />
<br />
''' FITS file structure '''<br />
<br />
The FITS files for the sky maps contain a minimal primary header with no data, and a ''BINTABLE'' extension (EXTENSION 1, EXTNAME = ''FREQ-MAP'') containing the data. The structure is shows schematically in the figure below. The ''FREQ-MAP'' extension contains a 3- or a 10-column table that contain the signal, hit-count and variance maps, all in Healpix format. The 3-column case is for intensity only maps, the 10-column case is for polarisation. The number of rows is the number of map pixels, which is Npix = 12 <math>N_{side}</math><sup>2</sup> for Healpix maps, where <math>N_{side}</math> = 1024 or 2048 for most the maps presented in this chapter.<br />
<br />
[[File:FITS_FreqMap.png | 550px | center | thumb | '''FITS file structure''']]<br />
<br />
Note that file sizes are ~0.6 GB for I-only maps and ~1.9 GB for I,Q,U maps at <math>N_{side}</math> 2048 and ~0.14 GB for I-only maps and ~0.45 GB for I,Q,U maps at <math>N_{side}</math> 1024 .<br />
<br />
Keywords indicate the coordinate system (GALACTIC), the Healpix ordering scheme (NESTED), the units (K_cmb or MJy/sr) of each column, and of course the frequency channel (FREQ). Where polarisation Q and U maps are provided, the ''COSMO'' polarisation convention (used in HEALPIX) is adopted, and it is specified in the ''POLCCONV'' keyword (see [[Sky_temperature_maps#Polarization_convention_used_in_the_Planck_project|this section]]. The COMMENT fields give a one-line summary of the product, and some other information useful for traceability within the DPCs. The original filename is also given in the ''FILENAME'' keyword. The ''BAD_DATA'' keyword gives the value used by Healpix to indicate pixels for which no signal is present (these will also have a hit-count value of 0). The main parameters are summarised below:<br />
<br />
<br />
{| border="1" cellpadding="3" cellspacing="0" align="center" style="text-align:left" width=800px<br />
|+ '''Sky map file data structure'''<br />
|- bgcolor="ffdead" <br />
!colspan="4" | 1. EXTNAME = 'FREQ-MAP' : Data columns<br />
|- bgcolor="ffdead" <br />
! Column Name || Data Type || Units || Description<br />
|-<br />
|I_STOKES || Real*4 || K_cmb or MJy/sr || The Stokes I map<br />
|-<br />
|Q_STOKES || Real*4 || K_cmb or MJy/sr || The Stokes Q map (optional)<br />
|-<br />
|U_STOKES || Real*4 || K_cmb or MJy/sr || The Stokes U map (optional)<br />
|-<br />
|HITS || Int*4 || none || The hit-count map<br />
|-<br />
|II_COV || Real*4 || K_cmb<sup>2</sup> or (MJy/sr)<sup>2</sup> || The II variance map<br />
|-<br />
|IQ_COV || Real*4 || K_cmb<sup>2</sup> or (MJy/sr)<sup>2</sup> || The IQ variance map (optional)<br />
|-<br />
|IU_COV || Real*4 || K_cmb<sup>2</sup> or (MJy/sr)<sup>2</sup> || The IQ variance map (optional)<br />
|-<br />
|QQ_COV || Real*4 || K_cmb<sup>2</sup> or (MJy/sr)<sup>2</sup> || The QQ variance map (optional)<br />
|-<br />
|QU_COV || Real*4 || K_cmb<sup>2</sup> or (MJy/sr)<sup>2</sup> || The QU variance map (optional)<br />
|-<br />
|UU_COV || Real*4 || K_cmb<sup>2</sup> or (MJy/sr)<sup>2</sup> || The UU variance map (optional)<br />
|-<br />
|- bgcolor="ffdead" <br />
! Keyword || Data Type || Value || Description<br />
|-<br />
|PIXTYPE || string || HEALPIX ||<br />
|-<br />
|COORDSYS || string || GALACTIC ||Coordinate system <br />
|-<br />
|ORDERING || string || NESTED || Healpix ordering<br />
|-<br />
|POLCCONV || String || COSMO || Polarization convention<br />
|-<br />
|NSIDE || Int || 1024 or 2048 || Healpix <math>N_{side}</math> <br />
|-<br />
|FIRSTPIX || Int*4 || 0 || First pixel number<br />
|-<br />
|LASTPIX || Int*4 || 12 <math>N_{side}</math><sup>2</sup> – 1 || Last pixel number<br />
|-<br />
|FREQ || string || nnn || The frequency channel <br />
|}<br />
<br />
<br />
The same structure applies to all ''SkyMap'' products, independent of whether they are full channel, survey of half-ring. The distinction between the types of maps is present in the FITS filename (and in the traceability comment fields).<br />
<br />
'''Polarization convention used in the Planck project'''<br />
<br />
The Planck collaboration used the COSMO convention for the polarization angle (as usually used in space based CMB missions), whereas other astronomical fields usually use the IAU convention. In the following document we report the difference between these two conventions, and the consequence if it is NOT taken into account correctly in the analysis.<br />
<br />
[[File:conventions.png|thumb|center|400px|'''Figure 1. COSMO convention (left) and IAU convention (right). The versor <math>\hat{z}</math> points outwards the pointing direction in COSMO, and inwards in IAU. The bottom panel refers to the plane tangent to the sphere.''']]<br />
<br />
Changing the orientation convention is equivalent to a transformation <math>\psi'=\pi-\psi</math> of the polarization angle (Figure 1). The consequence of this transformation is the inversion of the Stokes parameter <math>U</math>.<br />
The components of the polarization tensor in the helicity basis <math>\epsilon^{\pm}=1/\sqrt{2}(\hat{x}\pm i\hat{y})</math> are:<br />
<br />
<math><br />
(Q+iU)(\hat{n}) = \sum _{\ell m}a_{2,lm}{}_{2}Y_{\ell }^{m}(\hat{n})<br />
\\(Q-iU)(\hat{n}) = \sum _{\ell m}a_{-2,lm}{}_{2}Y_{\ell }^{m}(\hat{n})<br />
</math><br />
<br />
where <math>{}_{2}Y_{\ell }^{m}(\hat{n})</math> are the spin weighted spherical harmonic functions.<br />
The <math>E</math> and <math>B</math> modes can be defined as:<br />
<math><br />
E(\hat{n}) = \sum_{\ell m}a_{E,\ell m}Y_{\ell }^{m}(\hat{n})<br />
\\B(\hat{n}) = \sum_{\ell m}a_{B,\ell m}Y_{\ell }^{m}(\hat{n})<br />
</math><br />
<br />
where the coefficients <math>a_{E,\ell m}</math> and <math>a_{B,\ell m}</math> are derived from linear combinations of the <math>a_{2,\ell m}</math> , <math>a_{-2,\ell m}</math> defined implicitly in the first equation (<math>Q\pm iU</math>).<br />
<br />
[[File:test_gradient.jpg|thumb|center|400px|]]<br />
[[File:test_curl.jpg|thumb|center|400px|'''Figure 2. Error on Planck-LFI 70 GHz <math>EE</math> (top) and <math>BB</math> (bottom) spectra, in case of wrong choice of the coordinate system convention (IAU instead of COSMO).''']]<br />
<br />
The effect of the sign inversion of <math>U</math> on the polarization spectra is a non trivial mixing of <math>E</math> and <math>B</math> modes. <br />
<br />
An example of the typical error on <math>EE</math> and <math>BB</math> auto-spectra in case of a wrong choice of the polarization basis is shown in Figure 2.<br />
<br />
BE CAREFUL about the polarization convention you are using. If the IAU convention is used in computing the power spectra, the sign of the <math>U</math> component of the Planck maps must be inverted before computing <math>E</math> and <math>B</math> modes.<br />
<br />
''' Note on the convention used by the Planck Catalogue of Compact Sources (PCCS) '''<br />
For continuity with other compact sources catolgues, the Catalogue of Compact Sources provided by Planck follows the IAU convention, and the polarization angles are defined on an interval of [-90&deg;,90&deg;]. To switch to the COSMO convention, the polarization angles listed in the catalogue have to be shifted by 90&deg; and multiplied by -1.<br />
<br />
== References ==<br />
<References /><br />
<br />
</div><br />
</div><br />
<br />
<div class="toccolours mw-collapsible mw-collapsed" style="background-color: #EEE8AA;width:80%" ><br />
'''2013 Sky temperature maps'''<br />
<br />
<div class="mw-collapsible-content"><br />
<br />
'''General description'''<br />
<br />
<br />
Sky maps give the best estimate of the intensity of the signal from the sky after removal, as far as possible, of known systematic effects and of the dipole signals induced by the motion of the solar system in the CMB and of the Planck satellite in the solar system. Sky maps are provided for the nominal Planck mission and also, separately, for the first two single surveys, the third one being covered only for a small part during the nominal mission.The details of the start and end times of each are given in [[HFIpreprocessingstatics | this table]]. As a secondary product, maps with estimates of the Zodiacal light and Far-Side-Lobes contribution removed are also provided. <br />
<br />
For characterization purposes, are also provided maps covering the nominal survey but each one using only half of the available data. These are the ''ringhalf_{1|2}'' maps, which are built using the first and second half of the stable pointing part in each pointing period. These maps are used extensively to investigate the (high frequency) noise properties the maps themselves and of other products described elsewhere (see e.g., the [[HFI-Validation | data validation]] section).<br />
<br />
To help in further processing, there are also masks of the Galactic Plane and of point sources, each provided for several different depths.<br />
<br />
All sky maps are in Healpix format, with Nside of 2048 for HFI and of 1024 for LFI (note that the LFI 70 GHz has been delivered also at Nside of 2048 to be directly comparable with HFI maps), in Galactic coordinates, and Nested ordering. The signal is given in units of K<sub>cmb</sub> for 30-353 GHz, and of MJy/sr (for a constant $\nu F_\nu$ energy distribution ) for 545 and 857 GHz. Each sky map is packaged into a ''BINTABLE'' extension of a FITS file together with a hit-count map (or hit map, for short, giving the number of observation samples that are cumulated in a pixel, all detectors combined) and a variance map (determined from the half-ring maps), and additional information is given in the FITS file header. The structure of the FITS file is given in the [[#Format | FITS file structure]] section below.<br />
<br />
<br />
'''Types of maps '''<br />
<br />
; Full channel maps<br />
: Full channel maps are built using all the valid detectors of a frequency channel and cover the nominal mission. For HFI, the 143-8 and 545-3 bolometers are rejected entirely as they are seriously affected by RTS noise. The maps are displayed in the figures below. The range is the same from 30 - 143 GHz in order to show the CMB at the same level. At higher frequencies the range is increased in order to keep the Galactic Plane from invading the whole sky.<br />
<br />
<center><br />
<gallery style="padding:0 0 0 0;" perrow=3 widths=260px heights=160px> <br />
File: SkyMap30.png| '''Nominal mission, 30 GHz'''<br />
File: SkyMap44.png | '''Nominal mission, 44 GHz'''<br />
File: SkyMap70.png | '''Nominal mission, 70 GHz'''<br />
File: SkyMap100.png | '''Nominal mission, 100 GHz'''<br />
File: SkyMap143.png | '''Nominal mission, 143 GHz'''<br />
File: SkyMap217.png | '''Nominal mission, 217 GHz'''<br />
File: SkyMap353.png | '''Nominal mission, 353 GHz'''<br />
File: SkyMap545.png | '''Nominal mission, 545 GHz'''<br />
File: SkyMap857.png | '''Nominal mission, 857 GHz'''<br />
</gallery><br />
</center><br />
<br />
; Single survey maps <br />
: Single survey maps are built using all valid detectors of a frequency channel; they cover separately the different sky surveys. The surveys are defined as the times over which the satellite spin axis rotates but 180 degrees, which, due to the position of the detectors in the focal plane does not cover the full sky, but a fraction between ~80 and 90% depending on detector position.<br />
<br />
; Detector set or detector pairs maps<br />
: These are maps built from a subset of the detectors in a frequency channel, typically our of two PSB pairs (i.e., four poloarisation-sensitive bolometers with different orientation on the sky), for HFI in order to extract a single temperature map. While none of these maps are part of the first Planck data release, the concept of ''detset'' is used, and thus it is worth mentioning it here. In particular, information by detector set is available at the [[Frequency_maps_angular_power_spectra | sky power spectrum]] level and in the [[The RIMO | RIMO]].<br />
<br />
; Half-ring maps<br />
: Half-ring maps are built using only the first or the second half of the stable pointing period data. There are thus two half-ring maps per frequency channel named ''ringhalf_1'' and ''ringhalf_2'' respectively. These maps are built for characterization purposes in order to perform null tests. In particular, the difference between the two half-ring maps at a given frequency give a good estimate of the high frequency noise in the data (albeit biased low by ~0.5% for the HFI channels due to specifics of the TOI processing).<br />
<br />
; Masks<br />
: Masks are provided of the Galactic Plane and of the point sources. For the Galactic Plane, eight masks are given covering different fractions of the sky, and for the points sources two masks are given, at the 5 and 10 sigma level, for each Planck HFI frequency channel. These are generic masks, specific masks applicable to other products are delivered with the products themselves.<br />
<br />
''' Caveats and known issues'''<br />
<br />
The primary limitation of the HFI maps are<br />
* the absence of correction of the ADC non-linearities,<br />
* the far-side lobe contribution is not accounted for in the processing and in the calibration,<br />
* the dipole removal is based on the non-relativistic approximation which leaves a weak quadrupole component in the map.<br />
And thus the overall calibration accuracy is at the 0.2% level in 100-217 GHz channels<br />
<br />
The LFI 70 GHz maps at Nside=2048 should be considered as additional product, the default are the LFI maps at Nside=1024. No effective beam at Nside=2048 is provided, only at Nside=1024, for this reason the use of the effective beam with maps at Nside 2048 is discouraged.<br />
<br />
''' Map zero-level '''<br />
<br />
For the 100 to 857 GHz maps, the zero levels are set to their optimal levels for Galactic and CIB studies. A procedure for adjusting them to astrophysical values is given in the HFI Calibration paper {{PlanckPapers|planck2013-p03b}}.<br />
<br />
For the 30, 44 and 70 GHz, maps are corrected for zero level monopole by applying an offset correction, see LFI Calibration paper {{PlanckPapers|planck2013-p02b}} section 3.4 "Setting the zero levels in the maps". Note that the offset applied is indicated in the header as a comment keyword.<br />
<br />
''' The Zodiacal light and the Far-Side Lobes '''<br />
<br />
The figures below show the modeled Zodiacal light and Far Side Lobes projected onto the maps; they are simply the difference between the ''main product'' and the ''ZodiCorrected'' maps for the nominal mission. The units are given in the figures. The ''heat'' color table has been used in place of the standard Planck for clarity reasons. <br />
<center><br />
<gallery perrow=3 widths=260px heights=170px><br />
File: ZodiRes100.png | '''zodi/FSL rediduals - 100 GHz'''<br />
File: ZodiRes143.png | '''zodi/FSL rediduals - 143 GHz''' <br />
File: ZodiRes217.png | '''zodi/FSL rediduals - 217 GHz'''<br />
File: ZodiRes353.png | '''zodi/FSL rediduals - 353 GHz'''<br />
File: ZodiRes545.png | '''zodi/FSL rediduals - 545 GHz'''<br />
File: ZodiRes857.png | '''zodi/FSL rediduals - 857 GHz'''<br />
</gallery><br />
</center><br />
The effects of the FSLs are seen most clearly at the highest frequencies, as structures roughly symmetric about the center of the image, which corresponds to the location of the Galactic Centre, which is in turn the source of most of the radiation that is scattered into the FSLs.<br />
<br />
''' Artifacts near caustics of the scanning strategy '''<br />
<br />
The [[Survey scanning and performance|scanning strategy]] is such that regions around the Ecliptic poles are surveyed very deeply and compared to the average, and the transition from the nominal depth to the high depth, as shows on hit-count maps is very rapid, namely a few pixels, for a contrast of ~30. These transitions, or caustics in the maps, occur at different positions on the sky for different detectors, as the positions depend on their location in the focal plane of the instrument. As a result, when data from different detectors are combined to build a full channel map, the the weights of different detectors in the mix changes rapidly across the caustic, and given the remaining errors in the relative calibration of the detectors, a visible effect can be introduced in the maps, especially when the SNR is very high, i.e. at the highest frequencies and near bright regions like the Galactic Plane. Some examples are shown below.<br />
<br />
<center><br />
<gallery perrow=3 heights=260px widths=260pix ><br />
File: causta857.png | '''857 GHz intensity map around (272.5, -27)'''<br />
File: caustb857.png | '''857 GHz intensity map around (264.5, -37.5)'''<br />
File: caustc857.png | '''857 GHz intensity map around (98.5, 43)'''<br />
File: hita857.png | '''857 GHz hit count map around (272.5, -27)'''<br />
File: hitb857.png | '''857 GHz hit count map around (264.5, -37.5)'''<br />
File: hitc857.png | '''857 GHz hit count map around (98.5, 43)'''<br />
</gallery><br />
</center><br />
<br />
'''Production process'''<br />
<br />
<br />
Sky maps are produced by combining appropriately the data of all working detectors in a frequency channel over some period of the mission. They give the best estimate of the signal from the sky (unpolarised) after removal, as far as possible, of known systematic effects and of the dipole signals induced by the motion of the solar system in the CMB and of the Planck satellite in the solar system. In particular, they include the Zodiacal light emission (Zodi for short) and also the scattering from the far-side lobes of the beams (FSL). More on this below.<br />
<br />
''' HFI processing '''<br />
<br />
The inputs to the mapmaking are TOIs of signal that have been cleaned (as far as possible) of instrumental effects and calibrated in absorbed watts. While the processing involved is described in detail in the [[TOI processing|TOI processing]] section, we give a very brief summary here for convenience. That pipeline performs the following operations:<br />
<br />
; demodulation: this is performed around a variable level which is determined from the valid input data (a validity flag from a previous version of the processing is used for this purpose), and the data are converted to engineering units (V) using known conversion coefficients.<br />
; despiking: using the demodulated data converted to V (by the transfer function) the glitches are identified and fitted with templates. A glitch flag is produced that identifies the strongest part of the glitches, and a timeline of glitch tails is produced from the template fits, and subtracted from the demodulated timeline from step 1. Finally, the flagged ranges are replaced with data from an average over the pointing period (TBC)<br />
; dark template removal: the two dark bolometers are demodulated and despiked as above; the resulting timelines are then smoothed and used as an indicator of the overall temperature variations of the bolometer plate. Where the variations are consistent with each other, they are combined and removed from the bolometer signal timelines using appropriate coupling coefficients. The few percent of the data where they are not consistent are flagged on the timelines.<br />
; conversion to absorbed power: the timeline is converted to watts of absorbed power using the bolometer function. This includes a non-linearity correction; removal of the 4K cooler lines: the electromagnetic interference of the 4K cooler with the bolometer readout wires induces some sharp lines in the signal power spectra at frequencies of the 4K cooler's fundamental and its multiples, folded by the signal modulations. Fourier coefficients of the relevant lines are determined on a per-ring basis, and then removed from the data. The quality of the removal depends on the bolometer.<br />
; deconvolution by the time transfer function: this is done to correct for the non-instantaneous time response of the bolometers. The function itself is modeled using 4 parameters which are adjusted primarily on the planet data and also from comparisons of the northward and southward scans of the Galactic Plane. It is then removed using Fourier techniques, which has the side-effect of increasing the noise at high frequencies.<br />
; jump correction: removes some (relatively rare: 0.3 jumps per bolometer per pointing period, on average) jumps in the signal baseline. The jumps are detected characterized on smoothed TOIs, and corrected by adding a constant to part of the signal timeline. The origin of the jumps is not known.<br />
<br />
The results of this processing are a timeline of signal (in absorbed watts) and a ''valid data'' flag timeline for each of the 50 valid bolometers processed; these timelines contain the full sky signal, i.e., including the solar and orbital dipoles, the Zodiacal light, and contributions from the Far-Side lobes. The dipoles are necessary for the flux calibration and are removed at the mapmaking stage. The remaining two bolometers (143-8 and 535-3) show semi-random jumps in the signal level, typically jumping over 2-5 different ''pseudo-baseline'' levels, a behavior known as ''Random Telegraphic Signal'', so that these are commonly called the RTS bolometers. Finally, ring-level statistics of different types (mean, median, rms, kurtosis, etc.) are determined on a per-ring basis for all timelines, and a selection based on these statistics is used to discard anomalous rings, which are recorded in a ring-level flag for each valid bolometer timeline (see the [[TOI_processing#Discarded_rings| Discarded rings]] section). <br />
<br />
Throughout this processing, bright planets (Mars, Jupiter, Saturn, Uranus) and bright asteroids are masked in the timeline in order to avoid ringing effects in the processing. Since they move on the sky, the portion of the sky masked during one survey is observed during one, and no hole is left in the final map. In parallel, the planet data are processed in a similar way, but with different parameters for the despiking step, and without the final jump correction step. These results are processed separately to determine the beam shapes and the focal plane geometry.<br />
<br />
The pointing is determined starting from the AHF produced by MOC, which gives the direction and orientation of the LOS of a fiducial position in the focal plane at frequencies of 8Hz during stable pointing and 4 Hz during maneuvers (TBC for details, reference). This is interpolated to the times of data observation (ref to method), corrected for the wobble and other time-dependent offsets determined from the observed positions of a large number of sources around the sky, and finally converted to the LOS of each detector using the quaternions in the IMO (which are determined from observations of bright planets - see the [[Detector_pointing]] section). <br />
<br />
The mapmaking and calibration process is described in detail in the [[Map-making_LFI | Map-making]] section, where detailed references are found. In brief it consists of:<br />
<br />
; binning the TOI data onto ''rings'' : Healpix rings (HPRs) are used here, each ring containing the combined data of one pointing period. <br />
; flux calibration : at 100-353 GHz, the flux calibration factors are determined for each pointing period (or ring) from the solar-motion dipole, using the WMAP dipole as the reference, and after removal of the dipole signal induced by the motion of the Planck satellite in the solar system. This gain by ring is smoothed with a window of width 50 rings, which reveals an apparent variation of ~1-2% on a scale of 100s to 1000s of rings for the 100-217 GHz channels, and is applied. At 353GHz, where the solar motion dipole is weaker compared to the signal, no gain variation is detected (within the uncertainties), and a single fixed gain is applied to all rings. At 545 and 857 GHz the gain is determined from the observation of Uranus and Neptune (but not Jupiter which is too bright) and comparison to recent models made explicitly for this mission. A single gain is applied to all rings at these frequencies.<br />
; destriping : in order to remove low-frequency noise, an offset per ring is determined by minimizing the differences between HPRs at their crossings, and removed.<br />
; projection onto the map : the offset-corrected and flux-calibrated HPRs are projected onto Healpix maps, with the data of each bolometer weighted by a factor of 1/NET of that bolometer, and accounting for the slight different band transmission profiles of the bolometers in each band. <br />
<br />
These maps provide the main mission products. A second, reduced, set of maps, cleaned of the Zodiacal emission of the FSL leakage is also produced for the nominal mission and the two single surveys, but not for the half-rings (since the contribution would be the same for the two halves of each ring). For this purpose, the the Zodiacal emission and the FSL contamination, which are not fixed on the sky, are modeled separately at HPR-level, and subtracted from the signal HPR before projecting them onto the maps. <br />
<br />
Together with signal maps, hit count and variance maps are also produced. The hit maps give the (integer) number of valid TOI-level samples that contribute to the signal of each pixel. All valid samples are counted in the same way, i.e., there is no weighting factor applied. The variance maps project the white noise estimate, provided by the NETs, in the sky domain.<br />
<br />
''' LFI processing '''<br />
<br />
LFI maps were constructed with the Madam map-making code, version 3.7.4. The code is based on generalized destriping technique, where the correlated noise component is modeled as a sequence of constant offset, called baselines. A noise filter was used to constrain the baseline solution allowing the use of 1 second baselines.<br />
<br />
Radiometers were combined according to the horn-uniform weighting scheme to minimize systematics. The used weights are listed in [[Map-making LFI#Map-making|Map-making]]. The flagged samples were excluded from the analysis by setting their weights to $C_{w}^{-1}$ = 0. The galaxy region was masked out in the destriping phase, to reduce error arising from strong signal gradients. The polarization component was included in the analysis, although only the temperature maps are released. <br />
<br />
A detailed description of the map-making procedure is given in {{PlanckPapers|planck2013-p02}} and in section [[Map-making LFI#Map-making|Map-making]].<br />
<br />
'''Inputs'''<br />
<br />
<br />
''' HFI inputs '''<br />
<br />
* The cleaned TOIs of signal of each detector, together with their flags, produced by the [[TOI processing|TOI processing]] pipeline<br />
* The TOIs of pointing (quaternions), described in [[Detector_pointing]]<br />
* Bolometer-level characterization data, from the DPC's internal IMO (not distributed)<br />
* Planck orbit data used to compute and remove the earth dipole<br />
* WMAP solar dipole information used to calibrate the CMB channels<br />
* Planet models used to calibrate the Galactic channels.<br />
<br />
''' LFI inputs '''<br />
<br />
The Madam map-maker takes as an input:<br />
<br />
* The calibrated timelines (for details see [[TOI processing LFI|TOI Processing]])<br />
* The detector pointings (for details see [[Detector pointing|Detector pointing]])<br />
* The noise information in the form of three-parameter (white noise level ($\sigma$), slope, and knee frequency ($f_\mathrm{knee}$)) noise model (for details see [[The RIMO|RIMO]])<br />
<br />
'''Related products'''<br />
<br />
<br />
''' Masks '''<br />
<br />
Masks are provided of<br />
<br />
; the point sources<br />
: 15 masks are provided, three for the LFI (one mask for each frequency masking at the 4<math>\sigma</math> level) and 12 for the HFI (two masks for each frequency at the 5 and 10<math>\sigma</math> levels. For the HFI the masks can be used as they are, for the LFI they need to be downgraded to Nside=1024 except for the 70 GHz channel at Nside=2048 which does not need to be downgraded.<br />
<br />
; the Galactic Plane<br />
: 8 masks are provided giving 20, 40, 60, 70, 80, 90, 97, and 99% sky coverage in two different files, at Nside=2048. For the HFI they can be used as they are, for the LFI they need to be downgraded at Nside=1024 (note that if using the 70 GHZ at Nside=2048 no downgraded is needed)<br />
<br />
<br />
The masks are binary, in GALACTIC coordinates, and NESTED ordering. The table below give the filenames. <br />
<br />
<br />
{| class="wikitable" align="center" style="text-align:center" border="1" cellpadding="5" cellspacing="0" <br />
|+ '''FITS filenames for masks'''<br />
|-bgcolor="ffdead"<br />
! Frequency || LFI Point Source masks<br />
|-<br />
| '''30GHz''' || {{PLASingleFile|fileType=map|name=LFI_MASK_030-ps_2048_R1.00.fits|link=LFI_MASK_030-ps_2048_R1.00.fits}}<br />
|-<br />
| '''44GHz''' || {{PLASingleFile|fileType=map|name=LFI_MASK_044-ps_2048_R1.00.fits|link=LFI_MASK_044-ps_2048_R1.00.fits}}<br />
|-<br />
| '''70GHz''' || {{PLASingleFile|fileType=map|name=LFI_MASK_070-ps_2048_R1.00.fits|link=LFI_MASK_070-ps_2048_R1.00.fits}}<br />
|- bgcolor="ffdead"<br />
! colspan="2" | HFI Point Source masks<br />
|-<br />
| colspan="2" | {{PLASingleFile|fileType=map|name=HFI_Mask_PointSrc_2048_R1.10.fits|link=HFI_Mask_PointSrc_2048_R1.10.fits}}<br />
|- bgcolor="ffdead"<br />
! colspan="2" | Galactic Plane masks<br />
|-<br />
| colspan="2" | {{PLASingleFile|fileType=map|name=HFI_Mask_GalPlane_2048_R1.10.fits|link=HFI_Mask_GalPlane_2048_R1.10.fits}} <br />
|}<br />
<br />
<br />
The masks are shows below in a single figure. While this is quite clear for the Galactic Plane masks, it is less so for the point source masks, but it does give a clear perspective on how the latter are distributed over the sky.<br />
<br />
<center><br />
<gallery perrow=2 widths=300px heights=185px ><br />
File: HFI_GalPlaneMask.png | '''Galactic Plane masks'''<br />
File: HFI_PointSrcMask.png | '''PointSource masks'''<br />
</gallery><br />
</center><br />
<br />
''' File names '''<br />
<br />
<br />
The FITS filenames are of the form ''{H|L}FI_SkyMap_fff_nnnn_R1.nn_{coverage}_{type}.fits'', where ''fff'' are three digits to indicate the Planck frequency band, and ''nnnn'' is the Healpix Nside of the map, ''coverage'' indicates which part of the mission is covered, and the optional ''type'' indicates the subset of input data used. A full list of products, with links to them in the Archive, is given in the tables below.<br />
<br />
For the benefit of users who are only looking for the frequency maps with no additional information, we also provide a file combining the 9 frequency maps as separate columns in a single extension. The 9 columns in this file contain the intensity maps ONLY and no other information (hit maps and variance maps) is provided.<br />
<br />
{| class="wikitable" align="center" style="text-align:center" border="1" cellpadding="5" cellspacing="0" width=500px<br />
|+ '''FITS filenames'''<br />
|- bgcolor="ffdead"<br />
! Frequency || Full channel maps<br />
|-<br />
| '''30GHz''' || {{PLASingleFile|fileType=map|name=LFI_SkyMap_030_1024_R1.10_nominal.fits|link=LFI_SkyMap_030_1024_R1.10_nominal.fits}}<br />
|-<br />
| '''44GHz''' || {{PLASingleFile|fileType=map|name=LFI_SkyMap_044_1024_R1.10_nominal.fits|link=LFI_SkyMap_044_1024_R1.10_nominal.fits}}<br />
|-<br />
| '''70GHz''' || {{PLASingleFile|fileType=map|name=LFI_SkyMap_070_1024_R1.10_nominal.fits|link=LFI_SkyMap_070_1024_R1.10_nominal.fits}}<br />
|-<br />
| '''70GHz''' || {{PLASingleFile|fileType=map|name=LFI_SkyMap_070_2048_R1.10_nominal.fits|link=LFI_SkyMap_070_2048_R1.10_nominal.fits}}<br />
|-<br />
| '''100GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_100_2048_R1.10_nominal.fits|link=HFI_SkyMap_100_2048_R1.10_nominal.fits}}<br />
|-<br />
| '''143GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_143_2048_R1.10_nominal.fits|link=HFI_SkyMap_143_2048_R1.10_nominal.fits}}<br />
|-<br />
| '''217GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_217_2048_R1.10_nominal.fits|link=HFI_SkyMap_217_2048_R1.10_nominal.fits}}<br />
|-<br />
| '''353GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_353_2048_R1.10_nominal.fits|link=HFI_SkyMap_353_2048_R1.10_nominal.fits}}<br />
|-<br />
| '''545GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_545_2048_R1.10_nominal.fits|link=HFI_SkyMap_545_2048_R1.10_nominal.fits}}<br />
|-<br />
| '''857GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_857_2048_R1.10_nominal.fits|link=HFI_SkyMap_857_2048_R1.10_nominal.fits}}<br />
|- bgcolor="ffdead"<br />
! Frequency || Full channel, Zodi-corrected maps<br />
|-<br />
| '''100GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_100_2048_R1.10_nominal_ZodiCorrected.fits|link=HFI_SkyMap_100_2048_R1.10_nominal_ZodiCorrected.fits}} <br />
|-<br />
| '''143GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_143_2048_R1.10_nominal_ZodiCorrected.fits|link=HFI_SkyMap_143_2048_R1.10_nominal_ZodiCorrected.fits}}<br />
|-<br />
| '''217GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_217_2048_R1.10_nominal_ZodiCorrected.fits|link=HFI_SkyMap_217_2048_R1.10_nominal_ZodiCorrected.fits}}<br />
|-<br />
| '''353GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_353_2048_R1.10_nominal_ZodiCorrected.fits|link=HFI_SkyMap_353_2048_R1.10_nominal_ZodiCorrected.fits}}<br />
|-<br />
| '''545GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_545_2048_R1.10_nominal_ZodiCorrected.fits|link=HFI_SkyMap_545_2048_R1.10_nominal_ZodiCorrected.fits}}<br />
|-<br />
| '''857GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_857_2048_R1.10_nominal_ZodiCorrected.fits|link=HFI_SkyMap_857_2048_R1.10_nominal_ZodiCorrected.fits}}<br />
|- bgcolor="ffdead"<br />
! Frequency || Combined frequency maps<br />
|-<br />
| '''All''' || {{PLASingleFile|fileType=file|name=COM_MapSet_I-allFreqs_R1.10_nominal.fits|link=COM_MapSet_I-allFreqs_R1.10_nominal.fits}} <br />
|}<br />
<br />
<br />
{| class="wikitable" align="center" style="text-align:center" border="1" cellpadding="5" cellspacing="0" width=850px<br />
|+ '''FITS filenames'''<br />
|- bgcolor="ffdead"<br />
! Frequency || Survey 1 maps || Survey 2 maps<br />
|-<br />
| '''30GHz''' || {{PLASingleFile|fileType=map|name=LFI_SkyMap_030_1024_R1.10_survey_1.fits|link=LFI_SkyMap_030_1024_R1.10_survey_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=LFI_SkyMap_030_1024_R1.10_survey_2.fits|link=LFI_SkyMap_030_1024_R1.10_survey_2.fits}}<br />
|-<br />
| '''44GHz''' || {{PLASingleFile|fileType=map|name=LFI_SkyMap_044_1024_R1.10_survey_1.fits|link=LFI_SkyMap_044_1024_R1.10_survey_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=LFI_SkyMap_044_1024_R1.10_survey_2.fits|link=LFI_SkyMap_044_1024_R1.10_survey_2.fits}}<br />
|-<br />
| '''70GHz''' || {{PLASingleFile|fileType=map|name=LFI_SkyMap_070_1024_R1.10_survey_1.fits|link=LFI_SkyMap_070_1024_R1.10_survey_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=LFI_SkyMap_070_1024_R1.10_survey_2.fits|link=LFI_SkyMap_070_1024_R1.10_survey_2.fits}}<br />
|-<br />
| '''70GHz''' || {{PLASingleFile|fileType=map|name=LFI_SkyMap_070_2048_R1.10_survey_1.fits|link=LFI_SkyMap_070_2048_R1.10_survey_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=LFI_SkyMap_070_2048_R1.10_survey_2.fits|link=LFI_SkyMap_070_2048_R1.10_survey_2.fits}}<br />
|-<br />
| '''100GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_100_2048_R1.10_survey_1.fits|link=HFI_SkyMap_100_2048_R1.10_survey_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_100_2048_R1.10_survey_2.fits|link=HFI_SkyMap_100_2048_R1.10_survey_2.fits}}<br />
|-<br />
| '''143GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_143_2048_R1.10_survey_1.fits|link=HFI_SkyMap_143_2048_R1.10_survey_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_143_2048_R1.10_survey_2.fits|link=HFI_SkyMap_143_2048_R1.10_survey_2.fits}}<br />
|-<br />
| '''217GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_217_2048_R1.10_survey_1.fits|link=HFI_SkyMap_217_2048_R1.10_survey_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_217_2048_R1.10_survey_2.fits|link=HFI_SkyMap_217_2048_R1.10_survey_2.fits}}<br />
|-<br />
| '''353GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_353_2048_R1.10_survey_1.fits|link=HFI_SkyMap_353_2048_R1.10_survey_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_353_2048_R1.10_survey_2.fits|link=HFI_SkyMap_353_2048_R1.10_survey_2.fits}}<br />
|-<br />
| '''545GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_545_2048_R1.10_survey_1.fits|link=HFI_SkyMap_545_2048_R1.10_survey_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_545_2048_R1.10_survey_2.fits|link=HFI_SkyMap_545_2048_R1.10_survey_2.fits}}<br />
|-<br />
| '''857GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_857_2048_R1.10_survey_1.fits|link=HFI_SkyMap_857_2048_R1.10_survey_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_857_2048_R1.10_survey_2.fits|link=HFI_SkyMap_857_2048_R1.10_survey_2.fits}}<br />
|- bgcolor="ffdead"<br />
! Frequency || Survey 1 Zodi-corrected maps || Survey 2 Zodi-corrected maps<br />
|-<br />
| '''100GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_100_2048_R1.10_survey_1_ZodiCorrected.fits|link=HFI_SkyMap_100_2048_R1.10_survey_1_ZodiCorrected.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_100_2048_R1.10_survey_2_ZodiCorrected.fits|link=HFI_SkyMap_100_2048_R1.10_survey_2_ZodiCorrected.fits}}<br />
|-<br />
| '''143GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_143_2048_R1.10_survey_1_ZodiCorrected.fits|link=HFI_SkyMap_143_2048_R1.10_survey_1_ZodiCorrected.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_143_2048_R1.10_survey_2_ZodiCorrected.fits|link=HFI_SkyMap_143_2048_R1.10_survey_2_ZodiCorrected.fits}}<br />
|-<br />
| '''217GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_217_2048_R1.10_survey_1_ZodiCorrected.fits|link=HFI_SkyMap_217_2048_R1.10_survey_1_ZodiCorrected.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_217_2048_R1.10_survey_2_ZodiCorrected.fits|link=HFI_SkyMap_217_2048_R1.10_survey_2_ZodiCorrected.fits}}<br />
|-<br />
| '''353GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_353_2048_R1.10_survey_1_ZodiCorrected.fits|link=HFI_SkyMap_353_2048_R1.10_survey_1_ZodiCorrected.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_353_2048_R1.10_survey_2_ZodiCorrected.fits|link=HFI_SkyMap_353_2048_R1.10_survey_2_ZodiCorrected.fits}}<br />
|-<br />
| '''545GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_545_2048_R1.10_survey_1_ZodiCorrected.fits|link=HFI_SkyMap_545_2048_R1.10_survey_1_ZodiCorrected.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_545_2048_R1.10_survey_2_ZodiCorrected.fits|link=HFI_SkyMap_545_2048_R1.10_survey_2_ZodiCorrected.fits}}<br />
|-<br />
| '''857GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_857_2048_R1.10_survey_1_ZodiCorrected.fits|link=HFI_SkyMap_857_2048_R1.10_survey_1_ZodiCorrected.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_857_2048_R1.10_survey_2_ZodiCorrected.fits|link=HFI_SkyMap_857_2048_R1.10_survey_2_ZodiCorrected.fits}}<br />
|- bgcolor="ffdead"<br />
! Frequency || Half-ring 1 maps ||Half-ring 2 maps<br />
|-<br />
| '''30GHz''' || {{PLASingleFile|fileType=map|name=LFI_SkyMap_030_1024_R1.10_nominal_ringhalf_1.fits|link=LFI_SkyMap_030_1024_R1.10_nominal_ringhalf_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=LFI_SkyMap_030_1024_R1.10_nominal_ringhalf_2.fits|link=LFI_SkyMap_030_1024_R1.10_nominal_ringhalf_2.fits}}<br />
|-<br />
| '''44GHz''' || {{PLASingleFile|fileType=map|name=LFI_SkyMap_044_1024_R1.10_nominal_ringhalf_1.fits|link=LFI_SkyMap_044_1024_R1.10_nominal_ringhalf_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=LFI_SkyMap_044_1024_R1.10_nominal_ringhalf_2.fits|link=LFI_SkyMap_044_1024_R1.10_nominal_ringhalf_2.fits}}<br />
|-<br />
| '''70GHz''' || {{PLASingleFile|fileType=map|name=LFI_SkyMap_070_1024_R1.10_nominal_ringhalf_1.fits|link=LFI_SkyMap_070_1024_R1.10_nominal_ringhalf_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=LFI_SkyMap_070_1024_R1.10_nominal_ringhalf_2.fits|link=LFI_SkyMap_070_1024_R1.10_nominal_ringhalf_2.fits}}<br />
|-<br />
| '''70GHz''' || {{PLASingleFile|fileType=map|name=LFI_SkyMap_070_2048_R1.10_nominal_ringhalf_1.fits|link=LFI_SkyMap_070_2048_R1.10_nominal_ringhalf_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=LFI_SkyMap_070_2048_R1.10_nominal_ringhalf_2.fits|link=LFI_SkyMap_070_2048_R1.10_nominal_ringhalf_2.fits}}<br />
|-<br />
| '''100GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_100_2048_R1.10_nominal_ringhalf_1.fits|link=HFI_SkyMap_100_2048_R1.10_nominal_ringhalf_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_100_2048_R1.10_nominal_ringhalf_2.fits|link=HFI_SkyMap_100_2048_R1.10_nominal_ringhalf_2.fits}}<br />
|-<br />
| '''143GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_143_2048_R1.10_nominal_ringhalf_1.fits|link=HFI_SkyMap_143_2048_R1.10_nominal_ringhalf_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_143_2048_R1.10_nominal_ringhalf_2.fits|link=HFI_SkyMap_143_2048_R1.10_nominal_ringhalf_2.fits}}<br />
|-<br />
| '''217GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_217_2048_R1.10_nominal_ringhalf_1.fits|link=HFI_SkyMap_217_2048_R1.10_nominal_ringhalf_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_217_2048_R1.10_nominal_ringhalf_2.fits|link=HFI_SkyMap_217_2048_R1.10_nominal_ringhalf_2.fits}}<br />
|-<br />
| '''353GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_353_2048_R1.10_nominal_ringhalf_1.fits|link=HFI_SkyMap_353_2048_R1.10_nominal_ringhalf_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_353_2048_R1.10_nominal_ringhalf_2.fits|link=HFI_SkyMap_353_2048_R1.10_nominal_ringhalf_2.fits}}<br />
|-<br />
| '''545GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_545_2048_R1.10_nominal_ringhalf_1.fits|link=HFI_SkyMap_545_2048_R1.10_nominal_ringhalf_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_545_2048_R1.10_nominal_ringhalf_2.fits|link=HFI_SkyMap_545_2048_R1.10_nominal_ringhalf_2.fits}}<br />
|-<br />
| '''857GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_857_2048_R1.10_nominal_ringhalf_1.fits|link=HFI_SkyMap_857_2048_R1.10_nominal_ringhalf_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_857_2048_R1.10_nominal_ringhalf_2.fits|link=HFI_SkyMap_857_2048_R1.10_nominal_ringhalf_2.fits}}<br />
|}<br />
<br />
''' FITS file structure '''<br />
<br />
<br />
[[File:FITS_FreqMap.png | 500px | right | thumb | '''FITS file structure''']]<br />
<br />
The FITS files for the sky maps contain a minimal primary header with no data, and a ''BINTABLE'' extension (EXTENSION 1, EXTNAME = ''FREQ-MAP'') containing the data. The structure is shows schematically in the figure at right. <br />
<br />
The ''FREQ-MAP'' extension contains is a 3-column table that contain the signal, hit-count and variance maps, all in Healpix format, in columns 1, 2, and 3, respectively. The number of rows is 50331648 for HFI and LFI 70 GHz at Nside=2048 and 12582912 for LFI maps at Nside=1024 (N.B: Npix = 12 Nside^2). The three columns are ''I_STOKES'' for the intensity (or temperature) signal, ''HIT'' for the hit-count and ''II_COV'' for the variance. The exact order of the columns in the figure is indicative only, and the details can be found in the keywords. <br />
<br />
Keywords indicate the coordinate system (GALACTIC), the Healpix ordering scheme (NESTED), the units (K_cmb or MJy/sr) of each column, and of course the frequency channel (FREQ). The COMMENT fields give a one-line summary of the product, and some other information useful for traceability within the DPCs. The original filename is also given in the ''FILENAME'' keyword as are the datasum and the md5 checksum for the extension. The ''BAD_DATA'' keyword gives the value used by Healpix to indicate pixels for which no signal is present (these will also have a hit-count value of 0). The COMMENT fields give further information including some traceability data for the DPC's. The main parameters are summarised below:<br />
<br />
<br />
{| border="1" cellpadding="3" cellspacing="0" align="center" style="text-align:left" width=800px<br />
|+ '''Sky map file data structure'''<br />
|- bgcolor="ffdead" <br />
!colspan="4" | 1. EXTNAME = 'FREQ-MAP' : Data columns<br />
|- bgcolor="ffdead" <br />
! Column Name || Data Type || Units || Description<br />
|-<br />
|I_STOKES || Real*4 || K_cmb or MJy/sr || The signal map<br />
|-<br />
|HITS || Int*4 || none || The hit-count map<br />
|-<br />
|II_COV || Real*4 || K_cmb<sup>2</sup> or (MJy/sr)<sup>2</sup> || The variance map<br />
|- bgcolor="ffdead" <br />
! Keyword || Data Type || Value || Description<br />
|-<br />
|PIXTYPE || string || HEALPIX ||<br />
|-<br />
|COORDSYS || string || GALACTIC ||Coordinate system <br />
|-<br />
|ORDERING || string || NESTED || Healpix ordering<br />
|-<br />
|NSIDE || Int || 1024 or 2048 || Healpix Nside <br />
|-<br />
|FIRSTPIX || Int*4 || 0 || First pixel number<br />
|-<br />
|LASTPIX || Int*4 || 12582911 or 50331647 || Last pixel number<br />
|-<br />
|FREQ || string || nnn || The frequency channel <br />
|}<br />
<br />
<br />
The same structure applies to all ''SkyMap'' products, independent of whether they are full channel, survey of half-ring. The distinction between the types of maps is present in the FITS filename (and in the traceability comment fields).<br />
<br />
''' References'''<br />
<br />
<References /><br />
<br />
<br />
</div><br />
</div><br />
<br />
<br />
<br />
[[Category:Mission products|002]]</div>Azaccheihttps://wiki.cosmos.esa.int/planck-legacy-archive/index.php?title=Frequency_maps&diff=14111Frequency maps2018-07-06T13:46:35Z<p>Azacchei: /* File names */</p>
<hr />
<div>{{DISPLAYTITLE:Frequency maps in Temperature and Polarization}}<br />
==General description==<br />
<br />
Sky maps give the best estimate of the intensity and polarization (Stokes <i>Q</i> and <i>U</i> components), if available, of the signal from the sky after removal, as far as possible, of known systematic effects (mostly instrumental, but including also the solar and Earth-motion dipoles, Galactic stray light, and the zodiacal light). The Planck Collaboration has made three releases of maps, in 2013, 2015 and 2018. This section describes the 2018 release. For descriptions of the other two releases, please go to 2013, and 2015.<br />
<br />
In the 2013, 2015 and 2018 releases, sky maps are provided for the full Planck mission using all valid detectors in each frequency channel, and also for various subsets obtained by splitting the mission into various time ranges or into subsets of the detectors in a given channel, or by considering only odd or even pointing periods. These products are especially interesting for characterization purposes (see also the [[HFI-Validation | data validation]] section), though some are also useful for the study of source variability. The details of the start and end of the time ranges are given in the table below. <br />
<br />
For this (2018) release, HFI is providing a more limited subset of maps that include the full channel maps, the half-mission and the odd-even ring splits. Also, note that for the 353 GHz band, both full channel and PSBs only maps are provided, and that by default it is the PBS-only maps that are served.<br />
<br />
<br />
{| border="1" cellpadding="3" cellspacing="0" align="center" style="text-align:left" width=800px<br />
|+ '''Ranges for mission and surveys'''<br />
|- bgcolor="ffdead" <br />
! Range || ODs || HFI rings || pointing-IDs || Comment<br />
|-<br />
|Nominal mission || 91 - 563 || 240 - 14723 || 00004200 - 03180200 ||<br />
|-<br />
|Full mission || 91 - 974 || 240 - 27005 || 00004200 - 05322620 || For HFI<br />
|-<br />
|Full mission || 91 - 1543 || n/a || 00004200 - 06511160 || For LFI<br />
|-<br />
|Survey 1 || 91 - 270 || 240 - 5720 || 00004200 - 01059820 ||<br />
|-<br />
|Survey 2 || 270 - 456 || 5721 - 11194 || 01059830 - 02114520 ||<br />
|-<br />
|Survey 3 || 456 - 636 || 11195 - 16691 || 02114530 - 03193660 ||<br />
|-<br />
|Survey 4 || 636 - 807 || 16692 - 21720 || 03193670 - 04243900 ||<br />
|-<br />
|Survey 5 || 807 - 974 || 21721 - 26050 || 05267180 - 05322590 || End of mission for HFI<br />
|-<br />
|Survey 5 || 807 - 993 || n/a || 05267180 - 06344800 || End of survey for LFI<br />
|-<br />
|Survey 6 || 993 - 1177 || n/a || 06344810 - 06398120 || LFI only <br />
|-<br />
|Survey 7 || 1177 - 1358 || n/a || 06398130 - 06456410 || LFI only <br />
|-<br />
|Survey 8 || 1358 - 1543 || n/a || 06456420 - 06511160 || LFI only <br />
|-<br />
|HFI mission-half-1 || 91 - 531 || 240 - 13471 || 00004200 - 03155580 ||<br />
|-<br />
|HFI mission-half-2 || 531 - 974 || 13472 - 27005 || 03155590 - 05322590 ||<br />
|-<br />
|LFI Year 1 || 91 - 456 || n/a || 00004200 - 02114520 ||<br />
|-<br />
|LFI Year 2 || 456 - 807 || n/a || 02114530 - 04243900 ||<br />
|-<br />
|LFI Year 3 || 807 - 1177 || n/a || 05267180 - 06398120 ||<br />
|-<br />
|LFI Year 4 || 1177 - 1543 || n/a || 06398130 - 06511160 ||<br />
|-<br />
|}<br />
<br />
To help in further processing, there are also masks of the Galactic plane and of point sources, each provided for several different depths. <br />
<br />
All sky maps are in HEALPix format, with <i>N</i><sub>side</sub>=1024 (for LFI 30, 44, and 70GHz) and 2048 (for LFI 70GHz and HFI), in Galactic coordinates, and with nested ordering. <br />
<br />
'''WARNING''': The HEALPix convention for polarization is <b>not</b> the same as the IAU convention ([[#Polarization convention used in the Planck project|Section 8 on this page]]).<br />
<br />
The signal is given in units of K<sub>CMB</sub> for 30 to 353 GHz, and of MJy.sr<sup>-1</sup> (for a constant &nu;<i>I</i><sub>&nu;</sub> energy distribution) for 545 and 857 GHz. For each frequency channel, the intensity and polarization maps are packaged into a "BINTABLE" extension of a FITS file together with a hit-counts map (or "hits map", for short, giving the number of observation samples that are accumulated in a pixel, all detectors combined) and with the variance and covariance maps. Additional information is given in the FITS file header. The structure of the FITS file is given in the [[#FITS_file_structure | FITS file structure]] section below.<br />
<br />
==Production process==<br />
<br />
Sky maps are produced by appropriately combining the data from all working detectors in a frequency channel over some period of the mission. They give the best estimate of the signal from the sky (unpolarized) after removal, as far as possible, of known systematic effects and of the dipole signals induced by the motion of the solar system in the CMB and of the Planck satellite in the solar system. In particular, they include the zodiacal light emission ("zodi" for short) and also the scattering from the far sidelobes of the beams (FSL). More on this below.<br />
<br />
=== HFI processing ===<br />
<br />
The mapmaking and calibration process is described in detail in the [[Map-making_LFI | mapmaking]] section and in the {{PlanckPapers|planck2016-XLVI}} paper, where detailed references can be found. In brief, the timelines are cleaned and calibrated and converted into HealPix rings (HPRs), then ''SRoll'' is applied to destripe them in polarised space (removal of very low frequency noise by minimising differences at ring crossing points), to remove knows systematic effects (including the flux calibration), and to project them onto a HealPix map.<br />
<br />
The processing yields maps of the signal, hit counts and auto- and cross-variance maps for the 6 full channel and for a pseudo-channel built from the 353 PSBs only. For each channel HFI provides <br />
* a map for the full mission<br />
* two maps for each half-mission<br />
* two maps for built from odd or even rings only<br />
<br />
for a total of 35 maps. <br />
<br />
==== PR3 HFI products ====<br />
<br />
===== Healpix Pixel Rings (HPRs) =====<br />
''SRoll'' main products are the HFI frequency maps. Nevertheless, we also make available the Healpix Pixel Rings (HPRs) of those maps, ie. the data before projection. See [[Healpix_Rings_HFI| description of those files]].<br />
<br />
===== Frequency maps =====<br />
<br />
The 35 HFI frequency maps of the PR3 Legacy Release are the followings:<br />
<br />
{| border="1" cellpadding="3" cellspacing="0" align="center" style="text-align:left" width=800px<br />
|+ '''PR3 HFI frequency maps'''<br />
|- bgcolor="ffdead"<br />
!<br />
!100 GHz<br />
!143 GHz<br />
!217 GHz<br />
!353 GHz<br />
!353_PSB GHz<br />
!545 GHz<br />
!857 GHz<br />
|-<br />
| Full mission<br />
| I, Q, U<br />
| I, Q, U<br />
| I, Q, U<br />
| I, Q, U<br />
| I, Q, U<br />
| I<br />
| I<br />
|-<br />
| Half mission 1<br />
| I, Q, U<br />
| I, Q, U<br />
| I, Q, U<br />
| I, Q, U<br />
| I, Q, U<br />
| I<br />
| I<br />
|-<br />
| Half mission 2<br />
| I, Q, U<br />
| I, Q, U<br />
| I, Q, U<br />
| I, Q, U<br />
| I, Q, U<br />
| I<br />
| I<br />
|-<br />
| Odd rings<br />
| I, Q, U<br />
| I, Q, U<br />
| I, Q, U<br />
| I, Q, U<br />
| I, Q, U<br />
| I<br />
| I<br />
|-<br />
| Even rings<br />
| I, Q, U<br />
| I, Q, U<br />
| I, Q, U<br />
| I, Q, U<br />
| I, Q, U<br />
| I<br />
| I<br />
|}<br />
<br />
See [[Frequency_maps|description of those files]]. These maps are available on the [[https://www.cosmos.esa.int/web/planck/pla| Planck Legacy Archive]].<br />
<br />
<br />
=== LFI processing ===<br />
LFI maps were constructed with the MADAM mapmaking code, version 3.7.4. The code is based on a generalized destriping technique, where the correlated noise component is modelled as a sequence of constant offsets, called "baselines". A noise filter was used to constrain the baseline solution, allowing the use of 0.25-s and 1-s baselines for the 30 and 44GHz, and 70 GHz channels, respectively. See section 6 of {{PlanckPapers|planck2016-l02}}.<br />
<br />
<br />
Radiometers were combined according to the horn-uniform weighting scheme to minimize systematics. The flagged samples were excluded from the analysis by setting their weights to <i>C</i><sub>w</sub><sup>-1</sup> = 0. The Galaxy region was masked out in the destriping phase, to reduce errors arising from strong signal gradients. The polarization component was included in the analysis. <br />
<br />
; Dipole and Far Side Lobe correction: Input timelines are cleaned by the 4&pi;-convolved dipole and Galactic stray light, obtained as a convolution of the 4&pi; in-band far sidelobes and Galactic simulations, as explained in {{PlanckPapers|planck2016-l02}}. <br />
<br />
Scaling of the maps due to beam effects is taken into account in the LFI's beam functions (as provided in [[The_RIMO|the RIMO]]) which should be used for analysis of diffuse components.<br />
<br />
; Bandpass leakage correction :LFI high-resolution maps have been reseleased corrected for bandpass leakage or uncorrected. Further details about the procedure used to generate the bandpass correction maps can be found in section 7 of {{PlanckPapers|planck2016-l02}}.<br />
<br />
; Map zero-level : The 30, 44 and 70 GHz, maps are corrected for a zero-level monopole by applying an offset correction (see the LFI Calibration paper, {{PlanckPapers|planck2014-a06}}). Note that the offset applied is indicated in the header as a comment keyword.<br />
<br />
A detailed description of the mapmaking procedure is given in {{PlanckPapers|planck2013-p02}}, {{PlanckPapers|planck2014-a03}}, {{PlanckPapers|planck2014-a07}} and in the [[Map-making LFI#Map-making|Mapmaking]] section here, in {{PlanckPapers|planck2016-l02}} only a summary is reported.<br />
<br />
==Types of map ==<br />
<br />
=== Full-mission, full-channel maps (7 HFI, 4 LFI)===<br />
<br />
Full channel maps are built using all the valid detectors of a frequency channel and cover either the full or the nominal mission. For HFI, the 143-8 and 545-3 bolometers are rejected entirely, since they are seriously affected by RTS noise. HFI provides the Q and U components for the 100, 143, 217 and 353 GHz channels only. LFI provides the <i>I</i>, <i>Q</i>, and <i>U</i> maps for all the channels. Note that the HFI and LFI <i>Q</i> and <i>U</i> maps are corrected for bandpass leakage, version without correction for LFi is also provided. The <i>I</i>, <i>Q</i>, and <i>U</i> maps are displayed in the figures below. The colour range here is set using a histogram equalization scheme (from HEALPix) that is useful for these non-Gaussian data fields. For visualization purposes, the <i>Q</i> and <i>U</i> maps shown here have been smoothed with a 1&deg; Gaussian kernel, otherwise they look like noise to the naked eye. The 70 GHz full map is also available at <i>N</i><sub>side</sub>=2048.<br />
<br />
The high dynamic range colour scheme of the Planck maps is described [https://wiki.cosmos.esa.int/planck-legacy-archive/index.php/Planck_high_dynamic_range_colour_palette here].<br />
<br />
<center><br />
<gallery style="padding:0 0 0 0;" perrow=3 widths=260px heights=160px> <br />
File: LFI_030GHz_dx12_I.png| '''Full mission <i>I</i>, 30 GHz.'''<br />
File: LFI_044GHz_dx12_I.png| '''Full mission <i>I</i>, 44 GHz.'''<br />
File: LFI_070GHz_dx12_I.png| '''Full mission <i>I</i>, 70 GHz.'''<br />
File: SkyMap100e.png| '''Full mission <i>I</i>, 100 GHz.'''<br />
File: SkyMap143e.png| '''Full mission <i>I</i>, 143 GHz.'''<br />
File: SkyMap217e.png| '''Full mission <i>I</i>, 217 GHz.'''<br />
File: SkyMap353e.png| '''Full mission <i>I</i>, 353 GHz.'''<br />
File: SkyMap545e.png| '''Full mission <i>I</i>, 545 GHz.'''<br />
File: SkyMap857e.png| '''Full mission <i>I</i>, 857 GHz.'''<br />
</gallery><br />
</center><br />
<br><br />
<center><br />
<gallery style="padding:0 0 0 0;" perrow=3 widths=260px heights=160px> <br />
File: LFI_030GHz_dx12_Q.png| '''Full mission <i>Q</i>, 30 GHz.'''<br />
File: LFI_044GHz_dx12_Q.png | '''Full mission <i>Q</i>, 44 GHz.'''<br />
File: LFI_070GHz_dx12_Q.png | '''Full mission <i>Q</i>, 70 GHz.'''<br />
File: HFI_Skymap_100_full_bplcorrected_sm1deg_Qb.png | '''Full mission <i>Q</i>, 100 GHz.'''<br />
File: HFI_Skymap_143_full_bplcorrected_sm1deg_Qb.png | '''Full mission <i>Q</i>, 143 GHz.'''<br />
File: HFI_Skymap_217_full_bplcorrected_sm1deg_Qb.png | '''Full mission <i>Q</i>, 217 GHz.'''<br />
File: HFI_Skymap_353_full_bplcorrected_sm1deg_Qb.png | '''Full mission <i>Q</i>, 353 GHz.'''<br />
</gallery><br />
</center><br />
<br><br />
<center><br />
<gallery style="padding:0 0 0 0;" perrow=3 widths=260px heights=160px> <br />
File: LFI_030GHz_dx12_U.png| '''Full mission <i>U</i>, 30 GHz.'''<br />
File: LFI_044GHz_dx12_U.png | '''Full mission <i>U</i>, 44 GHz.'''<br />
File: LFI_070GHz_dx12_U.png | '''Full mission <i>U</i>, 70 GHz.'''<br />
File: HFI_Skymap_100_full_bplcorrected_sm1deg_Ub.png | '''Full mission <i>U</i>, 100 GHz.'''<br />
File: HFI_Skymap_143_full_bplcorrected_sm1deg_Ub.png | '''Full mission <i>U</i>, 143 GHz.'''<br />
File: HFI_Skymap_217_full_bplcorrected_sm1deg_Ub.png | '''Full mission <i>U</i>, 217 GHz.'''<br />
File: HFI_Skymap_353_full_bplcorrected_sm1deg_Ub.png | '''Full mission <i>U</i>, 353 GHz.'''<br />
</gallery><br />
<br />
</center><br />
<br />
=== Full mission light maps, full channel maps (7 HFI, 7 LFI)===<br />
<br />
These maps are based on the Full mission maps but contain fewer columns, IQU from 30 to 353 GHz, and I only at 545 and 857 GHz. These maps have been produced to reduce the transfer time of the most downloaded frequency full mission maps.<br />
<br />
=== Single-survey, full-channel maps (35 LFI)===<br />
<br />
Single-survey maps are built using all valid detectors of a frequency channel; they separately cover the different sky surveys. The surveys are defined as the times over which the satellite spin axis rotates by 180&deg;, which, due to the position of the detectors in the focal plane does not cover the full sky, but a fraction between about 80% and 90%, depending on detector position. During adjacent surveys the sky is scanned in opposite directions (more precisely it is the ecliptic equator that is scanned in opposite directions). While these are useful to investigate variable sources, they are also used to study the systematics of the time-response of the detectors as they scan bright sources, like the Galactic Plane, in different directions during different survey. Note that the HFI and LFI missions cover five and eight surveys, respectively, and in the case of HFI the last survey in incomplete.<br />
The 70 GHz survey maps are available also at <i>N</i><sub>side</sub>=2048. Note that LFI provides a special survey-map combination used in the low-&#8467; analysis; this maps, available at the three LFI frequencies, 30, 44, and 70 GHz, was built using the combination of Surveys 1, 3, 5, 6, 7, and 8.<br />
<br />
=== Year maps, full-channel maps (16 LFI)===<br />
<br />
These maps are built using the data of Surveys 1+2, Surveys 3+4, and so forth. They are used to study long-term systematic effects. The 70 GHz years maps are available also at <i>N</i><sub>side</sub>=2048.<br />
<br />
===Half-mission maps, full-channel maps (14 HFI, 12 LFI)===<br />
<br />
For HFI, the half mission is defined after eliminating those rings that are discarded for all bolometers, many of which occurred during the 5th survey when the "End-of-Life" tests were performed. The remaining rings are divided in half to define the two halves of the mission. This exercise is done for the full mission only.<br />
<br />
For LFI, instead of the half-mission maps, the following year combinations have been created: Year 1+2, Year 1+3, Year 2+4, Year 3+4,<br />
<br />
===Full mission, single-detector maps (22 LFI)===<br />
<br />
For LFI, all the 22 Radiometers maps are available, and (obviously) only in Stokes <i>I</i>.<br />
<br />
===Full-mission, detector-set or detector-pairs maps (8 LFI)===<br />
<br />
The objective here is to build independent temperature (<i>I</i>) and polarization (<i>Q</i> and <i>U</i>) maps using the two pairs of polarization-sensitive detectors of each channel where they are available, i.e., for the 44-353 GHz channels. The table below indicates which detectors were used to build each detector set (detset).<br />
<br />
{| border="1" cellpadding="3" cellspacing="0" align="center" style="text-align:left" width=600px<br />
|+ '''Definition of LFI detector pairs'''<br />
|- bgcolor="ffdead" <br />
!Frequency || Horn pair || Comment <br />
|-<br />
|44 GHz || 24 || This map is only in temperature<br />
|-<br />
|44 GHz || 25 and 26 || <br />
|-<br />
|70 GHz || 18 and 23 || Available also at <i>N</i><sub>side</sub>=2048<br />
|-<br />
|70 GHz || 19 and 22 || Available also at <i>N</i><sub>side</sub>=2048<br />
|-<br />
|70 GHz || 20 and 21 || Available also at <i>N</i><sub>side</sub>=2048<br />
|}<br />
<br />
===Half-ring maps (62 LFI)===<br />
<br />
These maps are similar to the ones described above, but are built using only the first or the second halves of each ring (or pointing period). The HFI provides half-ring maps for the full mission only, as well as for the full channel, the detsets, and the single bolometers. The LFI provides half-ring maps for the full mission in each channel (70 GHz also at <i>N</i><sub>side</sub>=2048), for the full-mission radiometers, and for the full-mission horn pairs.<br />
<br />
=== Odd and even rings maps (14 HFI)<br />
<br />
As the name indicates, these are generated by using only the odd or only the even rings.<br />
<br />
=== Caveats and known issues ===<br />
<br />
'''TBC'''<br />
<br />
==== Caveats when using the HFI frequency maps ====<br />
Some imperfections have shown up in the tests of the HFI PR3 maps that were previously hidden by higher-level systematics in the previous PR2 data. These lead to guidelines for the proper use of the HFI PR3 data.<br />
<br />
===== Monopoles =====<br />
Monopoles, which cannot be extracted from Planck data alone, are adjusted at each frequency (as was done in the previous PR2 release). For component separation, this provides maps that can be used directly in combination with other tracers.<br />
This monopole includes a CIB model, a diffuse ISM signal adjusted on the HI tracer, and a zodiacal emission signal adjusted to the proper absolute intensity.<br />
<br />
=====Use of the 353 GHz SWBs ===== <br />
We deliver two data sets: the recommended one not using the 353 GHz SWBs data, and the other one including the 353 GHz SWBs for specific use like, for example, increasing the signal to noise level at high multipoles.<br />
<br />
===== Color correction and component separation=====<br />
Different responses between bolometers to different foregrounds cannot be used with the PR3 release to extract component maps. Single bolometer maps computed by Sroll in a frequency band, are all adjusted by construction to the band average response.<br />
<br />
===== Sub-pixel effect in very bright regions===== <br />
The bandpass corrections have been optimized for high latitude regions which implied to reduce the noise of the CO and dust bandpass templates to avoid the introduction of significant correlated noise. The effect is negligible for dust but not for CO in very bright regions. See [[subpixel_HFI|detailled description]].<br />
<br />
===== Solar dipole residual===== <br />
The ''Planck'' 2015 Solar dipole is removed from the PR3 HFI maps to be consistent with LFI maps and to facilitate comparison with the previous PR2 ones. The best Solar dipole determination from HFI PR3 data shows a small shift in direction of about 1', but a 1.8 &mu;K lower amplitude. Removal of the ''Planck'' 2015 Solar dipole thus leaves a small but non-negligible dipole residual in the HFI PR3 maps. To correct for this, and adjust maps at the best photometric calibration, users of the HFI PR3 maps should:<br />
# put back into the maps the ''Planck'' 2015 Solar dipole (d,l,b)= (3364.5 &plusmn; 2.0 &mu;K, 264.00 &plusmn; 0.03&deg;, 48.24 &plusmn; 0.02&deg;),<br />
# include the [[#Calibration accuracy|absolute calibration frequency bias]], i.e., multiply by 1 minus the calibration bias,<br />
# lastly, remove the [[#HFI 2018 Solar dipole|HFI 2018 Solar dipole]].<br />
<br />
==Inputs==<br />
=== HFI inputs ===<br />
<br />
The HFI mapmaking takes as input:<br />
* the cleaned TOIs of the signal from each detector, together with their flags, produced by the [[TOI processing|TOI processing]] pipeline;<br />
* the TOIs of pointing (quaternions), described in [[Detector_pointing|Detector pointing]];<br />
* bolometer-level characterization data, from the DPC's internal IMO (not distributed);<br />
* Planck orbit data, used to compute and remove the Earth's dipole;<br />
* Planck solar dipole information, used to calibrate the CMB channels;<br />
* planet models used to calibrate the Galactic channels.<br />
<br />
=== LFI inputs ===<br />
<br />
The MADAM mapmaker takes as input:<br />
* the calibrated timelines (for details see [[TOI processing LFI|TOI Processing]]);<br />
* the detector pointings (for details see [[Detector_pointing|Detector pointing]]);<br />
* the noise information in the form of 3-parameter (white noise level &sigma;, slope, and knee frequency <i>f</i><sub>knee</sub>) noise model (for details see [[The RIMO|RIMO]]).<br />
<br />
==Related products==<br />
=== Masks ===<br />
This section presents the "general purpose" masks. Other masks specific to certain products are packaged with those products.<br />
<br />
Note that for this release, HFI has not produced any new masks. <br />
<br />
==== Gatactic Centre masks ====<br />
<br />
'''TBW'''<br />
<br />
<br />
====Point source masks [TO BE REMOVED ??]====<br />
<br />
For HFI and LFI two sets of point-source masks are provided. <br />
* Intensity masks, which remove sources detected with S/N > 5. <br />
* Polarisation masks, which remove sources that have polarization detection significance levels of 99.97 % or greater at the position of a source detected in intensity. They were derived from the polarization maps with dust foreground bandpass mismatch leakage corrections applied. The area excised around each source has a radius of 3σ (width) of the beam, i.e., 1.27 FWHM (for LFI the cut around each source has a radius of 32 arcmin at 30GHz, 27 arcmin at 44 GHz, and 13 arcmin at 70 GHz).<br />
<br />
Both sets of masks are found in the files ''HFI_Mask_PointSrc_2048_R2.00.fits'' and ''LFI_Mask_PointSrc_2048_R2.00.fits'', in which the first extension contains the intensity masks, and the second contains the polarization masks.<br />
<br />
====Galactic plane masks [TO BE REMOVED ??]====<br />
<br />
Eight Galactic emission masks are provided, giving 20, 40, 60, 70, 80, 90, 97, and 99% sky coverage, derived from the 353 GHz map after CMB subtraction. These are independent of frequency channel. Three versions are given: not apodized; and apodized by 2&deg; and 5&deg;. The filenames are ''HFI_Mask_GalPlane-apoN_2048_R2.00.fits'', where <i>N</i> = 0, 2, and 5.<br />
<br />
The masks are shown below. The eight "GalPlane" masks are combined (added together) and shown in a single figure for each of the three apodizations. While the result is quite clear for the case of no apodization, it is less so for the apodized case. The "PointSrc" masks are shown separately for the intensity case.<br />
<br />
<center><br />
<gallery perrow=3 widths=260px heights=160px ><br />
File: GalPlaneMask_apo0.png | '''Galactic plane masks, no apodization.'''<br />
File: GalPlaneMask_apo2.png | '''Galactic plane masks, apodized to 2&deg;.'''<br />
File: GalPlaneMask_apo5.png | '''Galactic plane masks, apodized to 5&deg;.'''<br />
File: PointSrcMask_100.png | '''Point source mask, 100 GHz.'''<br />
File: PointSrcMask_143.png | '''Point source mask, 143 GHz.'''<br />
File: PointSrcMask_217.png | '''Point source mask, 217 GHz.'''<br />
File: PointSrcMask_353.png | '''Point source mask, 343 GHz.'''<br />
File: PointSrcMask_545.png | '''Point source mask, 545 GHz.'''<br />
File: PointSrcMask_857.png | '''Point source mask, 857 GHz.'''<br />
</gallery><br />
</center><br />
<br />
== File names ==<br />
The FITS filenames are of the form ''{H|L}FI_SkyMap_fff{-tag}_Nside_R3.nn_{coverage}-{type}.fits'', where "fff" are three digits to indicate the Planck frequency band, "tag" indicates the single detector or the detset (no "tag" indicates full channel), "Nside" is the HEALPix <i>N</i><sub>side</sub> value of the map, "coverage" indicates which part of the mission is covered (full, half mission, survey, year, etc.), and the optional "type" indicates the subset of input data used. The table below lists the products by type, with the appropriate unix wildcards that form the full filename.<br />
<br />
{| class="wikitable" align="center" style="text-align"left" border="1" cellpadding="15" cellspacing="20" width=880px<br />
|+ '''HFI FITS filenames'''<br />
|- bgcolor="ffdead"<br />
! Coverage || Filename <br />
|-<br />
| Full channel, full mission ||HFI_SkyMap_fff{-tag}_2048_R3.??_full.fits<br />
|-<br />
| Full channel, half mission || HFI_SkyMap_fff{-tag}_2048_R3.??_halfmission-{1/2}.fits<br />
|-<br />
| Full channel, full mission, odd/even ring || HFI_SkyMap_fff{-tag}_2048_R3.??_{odd/even}ring.fits <br />
|}<br />
<br />
{| class="wikitable" align="center" style="text-align"left" border="1" cellpadding="15" cellspacing="20" width=1000px<br />
|+ '''LFI FITS filenames'''<br />
|- bgcolor="ffdead"<br />
! Coverage || Filename || Half-ring filename || Comment<br />
|-<br />
| Full channel, full mission ||LFI_SkyMap_???_1024_R3.??_full.fits ||LFI_SkyMap_???_1024_R2.??_full-ringhalf-?.fits || 70GHz is corrected for Template<br />
|-<br />
| Full channel, full mission BandPass corrected ||LFI_SkyMap_???-BPassCorrected_1024_R3.??_full.fits ||LFI_SkyMap_???-BPassCorrected_???_1024_R2.??_full-ringhalf-?.fits || 70GHz is corrected for Template<br />
|-<br />
| Full channel, single survey || LFI_SkyMap_???_1024_R3.??_survey-?.fits || n/a || n/a<br />
|-<br />
| Full channel, survey combination || LFI_SkyMap_???_1024_R3.??_survey-1-3-5-6-7-8.fits || n/a || n/a<br />
|-<br />
| Full channel, survey combination BandPass corrected|| LFI_SkyMap_???_1024_R3.??-BPassCorrected_survey-1-3-5-6-7-8.fits || n/a || n/a<br />
|-<br />
| Full channel, single year || LFI_SkyMap_???_1024_R3.??_year-?.fits || n/a || n/a<br />
|-<br />
| Full channel, single year BandPass corrected|| LFI_SkyMap_???-BPassCorrected_1024_R3.??_year-?.fits || n/a || n/a<br />
|-<br />
| Full channel, year combination || LFI_SkyMap_???_1024_R3.??_year?-?.fits || n/a || n/a<br />
|-<br />
| Full channel, year combination BandPass corrected|| LFI_SkyMap_???-BPassCorrected_1024_R3.??_year?-?.fits || n/a || n/a<br />
|-<br />
| Horn pair, full mission || LFI_SkyMap_???-??-??_1024_R3.??_full.fits || LFI_SkyMap_???_??-??_1024_R3.??_full-ringhalf-?.fits || n/a<br />
|-<br />
| Single radiometer, full mission || LFI_SkyMap_???-???_1024_R3.??_full.fits || LFI_SkyMap_???-???_1024_R3.??_full-ringhalf-?.fits || n/a<br />
|}<br />
<br />
For the benefit of users who are only looking for the frequency maps with no additional information, we also provide a file combining the nine frequency maps as separate columns in a single extension. The nine columns in this file contain the intensity maps <i>only</i> and no other information (hits maps or variance maps) is provided.<br />
<br />
== FITS file structure ==<br />
<br />
The FITS files for the sky maps contain a minimal primary header with no data, and a ''BINTABLE'' extension (EXTENSION 1, EXTNAME = ''FREQ-MAP'') containing the data. The structure is shown schematically in the figure below. The ''FREQ-MAP'' extension contains a 3- or 10-column table that contain the signal, hit-count, and variance maps, all in HEALPix format. The 3-column case is for intensity only maps, while the 10-column case is for polarization. The number of rows is the number of map pixels, which is <i>N</i><sub>pix</sub> = 12 <i>N</i><sub>side</sub><sup>2</sup> for HEALPix maps, where <i>N</i><sub>side</sub> = 1024 or 2048 for most the maps presented in this section.<br />
<br />
[[File:FITS_FreqMap.png | 550px | center | thumb | '''FITS file structure.''']]<br />
<br />
Note that file sizes are approximately 0.6 GB for <i>I</i>-only maps and 1.9 GB for <i>IQU</i> maps at <i>N</i><sub>side</sub>=2048, but about 0.14 GB for <i>I</i>-only maps and 0.45 GB for <i>IQU</i> maps at <i>N</i><sub>pix</sub>=1024 .<br />
<br />
Keywords indicate the coordinate system ("GALACTIC"), the HEALPix ordering scheme ("NESTED"), the units (K<sub>CMB</sub> or MJy.sr<sup>-1</sup>) of each column, and of course the frequency channel ("FREQ"). Where polarization <i>Q</i> and <i>U</i> maps are provided, the "COSMO" polarization convention (used in HEALPix) is adopted, and it is specified in the "POLCCONV" keyword (see [[Sky_temperature_maps#Polarization_convention_used_in_the_Planck_project|this section]]). The "COMMENT" fields give a one-line summary of the product, and some other information useful for traceability within the DPCs. The original filename is also given in the "FILENAME" keyword. The "BAD_DATA" keyword gives the value used by HEALPix to indicate pixels for which no signal is present (these will also have a hit-count value of 0). The main parameters are summarized in the table below.<br />
<br />
{| border="1" cellpadding="3" cellspacing="0" align="center" style="text-align:left" width=800px<br />
|+ '''Sky map file data structure'''<br />
|- bgcolor="ffdead" <br />
!colspan="4" | 1. EXTNAME = 'FREQ-MAP' : Data columns<br />
|- bgcolor="ffdead" <br />
! Column name || Data type || Units || Description<br />
|-<br />
|I_STOKES || Real*4 || K<sub>CMB</sub> or MJy.sr<sup>-1</sup> || Stokes <i>I</i> map<br />
|-<br />
|Q_STOKES || Real*4 || K<sub>CMB</sub> or MJy.sr<sup>-1</sup> || Stokes <i>Q</i> map (optional)<br />
|-<br />
|U_STOKES || Real*4 || K<sub>CMB</sub> or MJy.sr<sup>-1</sup> || Stokes <i>U</i> map (optional)<br />
|-<br />
|HITS || Int*4 || none || The hit-count map<br />
|-<br />
|II_COV || Real*4 || K<sub>CMB</sub><sup>2</sup> or (MJy.sr<sup>-1</sup>)<sup>2</sup> || <i>II</i> variance map<br />
|-<br />
|IQ_COV || Real*4 || K<sub>CMB</sub><sup>2</sup> or (MJy.sr<sup>-1</sup>)<sup>2</sup> || <i>IQ</i> variance map (optional)<br />
|-<br />
|IU_COV || Real*4 || K<sub>CMB</sub><sup>2</sup> or (MJy.sr<sup>-1</sup>)<sup>2</sup> || <i>IQ</i> variance map (optional)<br />
|-<br />
|QQ_COV || Real*4 || K<sub>CMB</sub><sup>2</sup> or (MJy.sr<sup>-1</sup>)<sup>2</sup> || <i>QQ</i> variance map (optional)<br />
|-<br />
|QU_COV || Real*4 || K<sub>CMB</sub><sup>2</sup> or (MJy.sr<sup>-1</sup>)<sup>2</sup> || <i>QU</i> variance map (optional)<br />
|-<br />
|UU_COV || Real*4 || K<sub>CMB</sub><sup>2</sup> or (MJy.sr<sup>-1</sup>)<sup>2</sup> || <i>UU</i> variance map (optional)<br />
|-<br />
|- bgcolor="ffdead" <br />
! Keyword || Data type || Value || Description<br />
|-<br />
|PIXTYPE || String || HEALPIX ||<br />
|-<br />
|COORDSYS || String || GALACTIC ||Coordinate system <br />
|-<br />
|ORDERING || String || NESTED || Healpix ordering<br />
|-<br />
|POLCCONV || String || COSMO || Polarization convention<br />
|-<br />
|NSIDE || Int || 1024 or 2048 || HEALPix <i>N</i><sub>side</sub> <br />
|-<br />
|FIRSTPIX || Int*4 || 0 || First pixel number<br />
|-<br />
|LASTPIX || Int*4 || 12 <i>N</i><sub>side</sub><sup>2</sup> – 1 || Last pixel number<br />
|-<br />
|FREQ || String || nnn || Frequency channel <br />
|}<br />
<br />
<br />
The same structure applies to all "SkyMap" products, independent of whether they are full channel, survey of half-ring. The distinction between the types of maps is present in the FITS filename (and in the traceability comment fields).<br />
<br />
==Polarization convention used in the Planck project==<br />
<br />
The FITS keyword "POLCCONV" defines the polarization convention of the data within the file.<br />
The Planck collaboration used the COSMO convention for the polarization angle (as usually adopted in space-based and other CMB missions), whereas other subfields of astronomy usually adopt the IAU convention. The basic difference comes down to whether one thinks of the light rays being emitted from the origin (the usual mathematics/physics convention) or converging on the observer from the sky (the usual astronomy convention), and hence the "obvious" choice is different for a physicists and for an astronomer. Given that CMB results are of interest to a wide range of both physicists and astronomers, there is no single choice of convention that everyone would regard as self-evident. Hence one simply has to be aware of the convention being adopted. Because of this the Planck Collaboration has taken pains to point out which convention is being used in publications and in data releases. In the following we describe the difference between these two conventions, and the consequence if it is <i>not</i> taken into account correctly in the analysis.<br />
<br />
[[File:conventions.png|thumb|center|400px|'''Figure 1. Polarization conventions, showing the COSMO convention (left) and IAU convention (right). The vector <math>\hat{z}</math> points in the outward direction in COSMO, and inwards in IAU. The bottom panel refers to the plane tangent to the sphere.''']]<br />
<br />
Changing the orientation convention is equivalent to a transformation &psi;'=&pi;-&psi; of the polarization angle (Figure 1). The consequence of this transformation is the inversion of the Stokes parameter <i>U</i>.<br />
The components of the polarization tensor in the helicity basis <math>\epsilon^{\pm}=(\hat{x}\pm i\hat{y})/\sqrt{2}</math> are<br />
<br />
<math><br />
(Q+iU)(\hat{n}) = \sum _{\ell m}a_{2,lm}{}_{2}Y_{\ell }^{m}(\hat{n}),<br />
\\(Q-iU)(\hat{n}) = \sum _{\ell m}a_{-2,lm}{}_{2}Y_{\ell }^{m}(\hat{n}),<br />
</math><br />
<br />
where <math>{}_{2}Y_{\ell }^{m}(\hat{n})</math> are the spin-weighted spherical harmonic functions.<br />
The <i>E</i> and <i>B</i> modes can be defined as<br />
<br />
<math><br />
E(\hat{n}) = \sum_{\ell m}a_{E,\ell m}Y_{\ell }^{m}(\hat{n}),<br />
\\B(\hat{n}) = \sum_{\ell m}a_{B,\ell m}Y_{\ell }^{m}(\hat{n}),<br />
</math><br />
<br />
where the coefficients <i>a<sub>E,&#8467;m</sub></i> and <i>a<sub>B,&#8467;m</sub></i> are derived from linear combinations of the <i>a<sub>2,&#8467;m</sub></i>, <i>a<sub>-2,&#8467;m</sub></i>, defined implicitly in the first equation (<i>Q</i>&plusmn; i<i>U</i>).<br />
<br />
[[File:test_gradient.jpg|thumb|center|400px|]]<br />
[[File:test_curl.jpg|thumb|center|400px|'''Figure 2. Error on Planck-LFI 70 GHz <i>EE</i> (top) and <i>BB</i> (bottom) power spectra, in the case of an incorrect choice being made for the polarization coordinate system convention (IAU instead of COSMO).''']]<br />
<br />
The effect of the sign inversion of <i>U</i> on the polarization spectra is a non-trivial mixing of <i>E</i> and <i>B</i> modes. <br />
An example of the typical error on <i>EE</i> and <i>BB</i> auto-spectra in the case of the wrong choice for the polarization basis is shown in Figure 2.<br />
<br />
<i>One should be careful</i> to be aware of the polarization convention that is being adopted. If the IAU convention is used in computing the power spectra, then the sign of the <i>U</i> component of the Planck maps must be inverted before computing the <i>E</i> and <i>B</i> modes.<br />
<br />
In astronomical applications it is common to define a pseudo-vector <i>P</i> to show the amplitude and orientation of<br />
polarization on a map. When plotting these line segments to show the orientation of the plane of polarization (or the orthogonal direction, often considered to be the projection of the magnetic field), the results are the same for both the COSMO and IAU conventions. This because the appearance of <i>P</i> is a property of the radiation and hence not affected by the sign of <i>U</i>.<br />
<br />
=== Note on the convention used in the Planck Catalogue of Compact Sources (PCCS) ===<br />
Planck non-cosmology papers sometimes follow the IAU convention for internal analysis, for ease of comparison with other studies (e.g., comparison of Planck-derived thermal dust emission polarization with the optical polarization of starlight). Nevertheless, Planck data products, such as component-separated maps, still use the COSMO convention. The one exception is for the compact source catalogue. Because catalogues of astronomical objects found by Planck need to be compared directly with other source catalogues, the polarized sources described in the Planck Catalogue of Compact Sources follow the IAU convention, and the polarization angles are defined on an interval of [-90&deg;,90&deg;]. To switch to the COSMO convention, the polarization angles listed in the catalogue should be shifted by 90&deg; and multiplied by -1.<br />
<br />
== References ==<br />
<References /><br />
<br />
<br />
<span style="background:green"><br />
<br />
<span style="background:green"><br />
== Previous releases ==<br />
<br />
<div class="toccolours mw-collapsible mw-collapsed" style="background-color: #FFDAB9;width:80%" ><br />
'''2015 Sky temperature and polarization maps'''<br />
<br />
<div class="mw-collapsible-content"><br />
<br />
<br />
'''General description'''<br />
<br />
Sky maps give the best estimate of the intensity and polarization (Stokes Q and U components), if available, of the signal from the sky after removal, as far as possible, of known systematic effects (mostly instrumental, but including also the solar and earth-motion dipole, Galactic strylight and the Zodiacal light). Sky maps are provided for the full Planck mission using all valid detectors in each frequency channel, and also for various subsets by splitting the mission in various time ranges or in subsets of the detectors in a given channel. These products are useful for the study of source variability, but they are especially interesting for characterisation purposes (see also the [[HFI-Validation | data validation]] section). The details of the start and end of the time ranges are given in the table below.<br />
<br />
To help in further processing, there are also masks of the Galactic Plane and of point sources, each provided for several different depths.<br />
<br />
All sky maps are in Healpix format, with Nside of 1024 (LFI 30, 44 and 70) and 2048 (LFI 70 and HFI), in Galactic coordinates, and Nested ordering. <br />
<br />
;WARNING: the Healpix convention for polarization is NOT the same as the IAU convention - see Section 8 in this page.<br />
<br />
The signal is given in units of K<sub>cmb</sub> for 30-353 GHz, and of MJy/sr (for a constant <math>\nu F_\nu</math> energy distribution ) for 545 and 857 GHz. For each frequency channel, the intensity and polarization maps are packaged into a ''BINTABLE'' extension of a FITS file together with a hit-count map (or hit map, for short, giving the number of observation samples that are cumulated in a pixel, all detectors combined) and with the variance and covariance maps. Additional information is given in the FITS file header. The structure of the FITS file is given in the [[#FITS_file_structure | FITS file structure]] section below. <br />
<br />
; R2.00 : this first release (Jan 2015) contains polarisation data for the 353 GHz channel only.<br />
; R2.01 : this second release (May 2015) adds polarisation data to the 100-217 GHz channels.<br />
; R2.02 : a full re-release to correct the Healpix bad pixel value in the maps which was altered during the preparation of the maps and not reset to the correct value (the valid pixels are unchanged). It also fixes some FITS keywords, and includes a full re-release of the Zodi correction maps, with the 100-217 GHz one now including the polarisation correction)<br />
<br />
{| border="1" cellpadding="3" cellspacing="0" align="center" style="text-align:left" width=800px<br />
|+ '''Ranges for mission and surveys'''<br />
|- bgcolor="ffdead" <br />
! Range || ODs || HFI rings || pointing-IDs || Comment<br />
|-<br />
|nominal mission || 91 - 563 || 240 - 14723 || 00004200 - 03180200 ||<br />
|-<br />
|full mission || 91 - 974 || 240 - 27005 || 00004200 - 05322620 || for HFI<br />
|-<br />
|full mission || 91 - 1543 || n/a || 00004200 - 06511160 || for LFI<br />
|-<br />
|Survey 1 || 91 - 270 || 240 - 5720 || 00004200 - 01059820 ||<br />
|-<br />
|Survey 2 || 270 - 456 || 5721 - 11194 || 01059830 - 02114520 ||<br />
|-<br />
|Survey 3 || 456 - 636 || 11195 - 16691 || 02114530 - 03193660 ||<br />
|-<br />
|Survey 4 || 636 - 807 || 16692 - 21720 || 03193670 - 04243900 ||<br />
|-<br />
|Survey 5 || 807 - 974 || 21721 - 27005 || 05267180 - 05322590 || end of mission for HFI<br />
|-<br />
|Survey 5 || 807 - 993 || n/a || 05267180 - 06344800 || end of survey for LFI<br />
|-<br />
|Survey 6 || 993 - 1177 || n/a || 06344810 - 06398120 || LFI only <br />
|-<br />
|Survey 7 || 1177 - 1358 || n/a || 06398130 - 06456410 || LFI only <br />
|-<br />
|Survey 8 || 1358 - 1543 || n/a || 06456420 - 06511160 || LFI only <br />
|-<br />
|Survey 9 || 1543 - 1604 || n/a || 06511170 - 06533320 || LFI only Not in this delivery<br />
|-<br />
|HFI mission-half-1 || 91 - 531 || 240 - 13471 || 00004200 - 03155580 ||<br />
|-<br />
|HFI mission-half-2 || 531 - 974 || 13472 - 27005 || 03155590 - 05322590 ||<br />
|-<br />
|LFI Year 1 || 91 - 456 || n/a || 00004200 - 02114520 ||<br />
|-<br />
|LFI Year 2 || 456 - 807 || n/a || 02114530 - 04243900 ||<br />
|-<br />
|LFI Year 3 || 807 - 1177 || n/a || 05267180 - 06398120 ||<br />
|-<br />
|LFI Year 4 || 1177 - 1543 || n/a || 06398130 - 06511160 ||<br />
|-<br />
|}<br />
<br />
'''Production process'''<br />
<br />
Sky maps are produced by combining appropriately the data of all working detectors in a frequency channel over some period of the mission. They give the best estimate of the signal from the sky (unpolarised) after removal, as far as possible, of known systematic effects and of the dipole signals induced by the motion of the solar system in the CMB and of the Planck satellite in the solar system. In particular, they include the Zodiacal light emission (Zodi for short) and also the scattering from the far-side lobes of the beams (FSL). More on this below.<br />
<br />
''' HFI processing '''<br />
<br />
The mapmaking and calibration process is described in detail in the [[Map-making_LFI | Map-making]] section and in the {{PlanckPapers|planck2014-a09}} paper, where detailed references are found. In brief it consists of:<br />
<br />
; binning the TOI data onto ''rings'' : Healpix rings (HPRs) are used here, each ring containing the combined data of one pointing period. <br />
; flux calibration : at 100-353 GHz, the flux calibration factors are determined by correlating the signal with the orbital dipole, which is determined very accurately from the Planck satellite orbital parameters provided by Flight Dynamics. This provides a single gain factor per bolometer. At 545 and 857 GHz the gain is determined from the observation of Uranus and Neptune (but not Jupiter which is too bright) and comparison to recent models made explicitly for this mission. A single gain is applied to all rings at these frequencies.<br />
; destriping : in order to remove low-frequency noise, an offset per ring is determined by minimizing the differences between HPRs at their crossings, and removed.<br />
; Zodiacal light correction : a Zodiacal light model is used to build HPRs of the the Zodi emission, which is subtracted from the calibrated HPRs.<br />
; projection onto the map : the offset-corrected, flux-calibrated, and Zodi-cleaned HPRs are projected onto Healpix maps, with the data of each bolometer weighted by a factor of 1/NET of that bolometer.<br />
<br />
These steps are followed by some post-processing which is designed to prepare the maps for the component separation work. This post processing consists of: <br />
<br />
; Dust bandpass leakage correction : the Q and U maps are corrected for the intensity-to-polarisation leakage caused by the foregrounds having a non-CMB spectrum, and as a consequence of the non-identical bandpasses on the different detectors (bandpass mismatch, or BPM). This correction is determined using the ''ground'' method as described in Section 7.3 of {{PlanckPapers|planck2014-a09}}. These correction maps can be found in the Planck Legacy Archive as ''HFI_CorrMap_???-dustleak-ground_2048_R2.0?_{coverage}.fits''. The correction is applied by subtracting the correction map from the corresponding input map. This correction is not applied to the nominal mission maps in order to maintain compatibility with the PR1 products. ''In fact this correction was computed and applied only to the products used in component separation'', so they were not applied to the single survey maps and to the half-ring maps, which are considered characterisation products.<br />
; Far Side Lobe calibration correction : the 100-217 maps are multiplied by factors of 1.00087, 1.00046, and 1.00043, respectively, to compensate for the non-removal of the far-side lobes, and similarly the corresponding covariance maps have also been corrected by multiplication by the square of the factor.<br />
; Fill missing pixels : missing pixels are filled in with a value that is the mean of valid pixels within a given radius. A radius of 1 deg is used for the full channel maps, and 1.5 deg is used for the detset maps. This step is not applied to the single survey maps since they have large swaths of the sky that are not covered.<br />
<br />
; Map zero-level : for the 100 to 857 GHz maps, the zero levels are set to their optimal levels for Galactic and CIB studies. A procedure for adjusting them to astrophysical values is given in the HFI Mapmaking and Calibration paper {{PlanckPapers|planck2014-a09}}.<br />
<br />
These maps provide the main mission products. Together with signal maps, hit count, variance, and variance maps are also produced. The hit maps give the (integer) number of valid TOI-level samples that contribute to the signal of each pixel. All valid samples are counted in the same way, i.e., there is no weighting factor applied. The variance maps project the white noise estimate, provided by the NETs, in the sky domain.<br />
<br />
Note that the nominal mission maps have not had the post-processing applied, which makes them more easily comparable to the PR1 products.<br />
<br />
''' LFI processing '''<br />
LFI maps were constructed with the Madam map-making code, version 3.7.4. The code is based on generalized destriping technique, where the correlated noise component is modeled as a sequence of constant offset, called baselines. A noise filter was used to constrain the baseline solution allowing the use of 0.25 s and 1 second baselines for the 30 and 44, 70 GHz respectively.<br />
<br />
Radiometers were combined according to the horn-uniform weighting scheme to minimize systematics. The used weights are listed in [[Map-making LFI#Map-making|Map-making]]. The flagged samples were excluded from the analysis by setting their weights to <math>C_{w}^{-1}</math> = 0. The galaxy region was masked out in the destriping phase, to reduce error arising from strong signal gradients. The polarization component was included in the analysis... <br />
<br />
; Dipole and Far Side Lobe correction : input timelines are cleaned by 4pi convolved dipole and Galactic Straylight obtained as convolution of the 4pi in band far sidelobes and Galactic Simulation as explained in Section 7.4 of {{PlanckPapers|planck2014-a03}}. <br />
<br />
Beam effects on the LFI maps are described in Section 7.1 of {{PlanckPapers|planck2014-a03}}. Scaling of the maps due to beam effects is taken into account in the LFI's beam functions (as provided in the RIMO, give reference) which should be used for analysis of diffuse components. To compute the flux densities of compact sources, correction must be made for beam effects (see Table 8 of {{PlanckPapers|planck2014-a03}})."<br />
<br />
; Bandpass leakage correction : '''as opposed to the HFI, the LFI high resolution maps have not been corrected for bandpass leakage. Only low resolution (nside 256) maps are provided with the bandpass correction'''. The correction maps (LFI_CorrMap_0??-BPassCorr_*.fits) can be found in the Planck Legacy Archive. Further details about the procedure used to generate the bandpass correction maps can be found in Section 11 of {{PlanckPapers|planck2014-a03}}.<br />
<br />
; Map zero-level : for the 30, 44 and 70 GHz, maps are corrected for zero level monopole by applying an offset correction, see LFI Calibration paper {{PlanckPapers|planck2014-a06}}. Note that the offset applied is indicated in the header as a comment keyword.<br />
<br />
A detailed description of the map-making procedure is given in {{PlanckPapers|planck2013-p02}}, {{PlanckPapers|planck2014-a03}}, {{PlanckPapers|planck2014-a07}} and in section [[Map-making LFI#Map-making|Map-making]].<br />
<br />
'''Types of maps '''<br />
<br />
''' Full mission, full channel maps (6 HFI, 4 LFI)'''<br />
<br />
Full channel maps are built using all the valid detectors of a frequency channel and cover the either the full or the nominal mission. For HFI, the 143-8 and 545-3 bolometers are rejected entirely as they are seriously affected by RTS noise. HFI provides the Q and U components for the 100, 143, 217 and 353 GHz channels only. LFI provides the I, Q and U maps for all the channels. Reminder: HFI Q and U maps are corrected for bandpass leakage but LFI Q and U maps are not. The I, Q and U maps are displayed in the figures below. The color range is set using a histogram equalisation scheme (from HEALPIX) that is useful for these non-Gaussian data fields. For visualization purposes, the Q and U maps shown here have been smoothed with a 1 degree Gaussian kernel, otherwise they look like noise to the naked eye.<br />
The 70 GHz full map is available also at <math>N_{side}</math> 2048.<br />
<br />
<center><br />
<gallery style="padding:0 0 0 0;" perrow=3 widths=260px heights=160px> <br />
File: SkyMap30e.png| '''Full mission I, 30 GHz'''<br />
File: SkyMap44e.png | '''Full mission I, 44 GHz'''<br />
File: SkyMap70e.png | '''Full mission I, 70 GHz'''<br />
File: SkyMap100e.png | '''Full mission I, 100 GHz'''<br />
File: SkyMap143e.png | '''Full mission I, 143 GHz'''<br />
File: SkyMap217e.png | '''Full mission I, 217 GHz'''<br />
File: SkyMap353e.png | '''Full mission I, 353 GHz'''<br />
File: SkyMap545e.png | '''Full mission I, 545 GHz'''<br />
File: SkyMap857e.png | '''Full mission I, 857 GHz'''<br />
</gallery><br />
</center><br />
<br><br />
<center><br />
<gallery style="padding:0 0 0 0;" perrow=3 widths=260px heights=160px> <br />
File: LFI_SkyMap_030_1024_R2.01_full_Qb_sm1deg.png| '''Full mission Q, 30 GHz'''<br />
File: LFI_SkyMap_044_1024_R2.01_full_Qb_sm1deg.png | '''Full mission Q, 44 GHz'''<br />
File: LFI_SkyMap_070_1024_R2.01_full_Qb_sm1deg.png | '''Full mission Q, 70 GHz'''<br />
File: HFI_Skymap_100_full_bplcorrected_sm1deg_Qb.png | '''Full mission Q, 100 GHz'''<br />
File: HFI_Skymap_143_full_bplcorrected_sm1deg_Qb.png | '''Full mission Q, 143 GHz'''<br />
File: HFI_Skymap_217_full_bplcorrected_sm1deg_Qb.png | '''Full mission Q, 217 GHz'''<br />
File: HFI_Skymap_353_full_bplcorrected_sm1deg_Qb.png | '''Full mission Q, 353 GHz'''<br />
</gallery><br />
</center><br />
<br><br />
<center><br />
<gallery style="padding:0 0 0 0;" perrow=3 widths=260px heights=160px> <br />
File: LFI_SkyMap_030_1024_R2.01_full_Ub_sm1deg.png| '''Full mission U, 30 GHz'''<br />
File: LFI_SkyMap_044_1024_R2.01_full_Ub_sm1deg.png | '''Full mission U, 44 GHz'''<br />
File: LFI_SkyMap_070_1024_R2.01_full_Ub_sm1deg.png | '''Full mission U, 70 GHz'''<br />
File: HFI_Skymap_100_full_bplcorrected_sm1deg_Ub.png | '''Full mission U, 100 GHz'''<br />
File: HFI_Skymap_143_full_bplcorrected_sm1deg_Ub.png | '''Full mission U, 143 GHz'''<br />
File: HFI_Skymap_217_full_bplcorrected_sm1deg_Ub.png | '''Full mission U, 217 GHz'''<br />
File: HFI_Skymap_353_full_bplcorrected_sm1deg_Ub.png | '''Full mission U, 353 GHz'''<br />
</gallery><br />
<br />
</center><br />
<br />
''' Full mission light maps, full channel maps (6 HFI, 7 LFI) '''<br />
<br />
These maps are based on the Full mission maps but contain fewer columns, IQU from 30 to 353 GHz, and I only at 545 and 857 GHz. These maps have been produced to reduce the transfer time of the most downloaded frequency full mission maps.<br />
<br />
''' Nominal mission, full channel maps (6 HFI) '''<br />
<br />
These maps are similar to the ones above, but cover the nominal mission only. They are meant primarily to be compared to the PR1 products in order to see the level of improvements in the processing. Because of this, they are produced in Temperature only, and have not had the post-processing applied.<br />
<br />
''' Single survey, full channel maps (30 HFI, 35 LFI)'''<br />
<br />
Single survey maps are built using all valid detectors of a frequency channel; they cover separately the different sky surveys. The surveys are defined as the times over which the satellite spin axis rotates but 180 degrees, which, due to the position of the detectors in the focal plane does not cover the full sky, but a fraction between ~80 and 90% depending on detector position. During adjacent surveys the sky is scanned in opposite directions. More precisely it is the ecliptic equator that is scanned in opposite directions. While these are useful to investigate variable sources, they are also used to study the systematics of the time-response of the detectors as they scan bright sources, like the Galactic Plane, in different directions during different survey. Note that the HFI and LFI missions cover 5 and 8 surveys, respectively, and in case of HFI the last survey in incomplete.<br />
The 70 GHz surveys maps are available also at <math>N_{side}</math> 2048.<br />
Note LFI provide a special surveys maps combination used in the low l analysis. This maps, available at the three LFI frequency 30, 44 and 70 GHz, was built using the combination of survey 1, 3, 5, 6, 7 and 8. <br />
<br />
''' Year maps, full channel maps (12 HFI, 16 LFI)'''<br />
<br />
These maps are built using the data of surveys 1+2, surveys 3+4, and so forth. They are used to study long-term systematic effects.<br />
The 70 GHz years maps are available also at <math>N_{side}</math> 2048.<br />
<br />
'''Half-mission maps, full channel maps (12 HFI, 12 LFI)'''<br />
<br />
For HFI, the half mission is defined after eliminating those rings discarded for all bolometers. There are 347 such rings, may of which are during the 5th survey when the ''End-of-Life'' tests were performed. The remaining 26419 rings are divided in half (up to the odd ring) to define the two halves of the mission. This exercise is done for the full mission only.<br />
<br />
For LFI instead of the half-mission the following year combination has been created: Year 1+2, Year 1+3, Year 2+4, Year 3+4, <br />
<br />
'''Full mission, single detector maps (18 HFI, 22 LFI)'''<br />
<br />
IN case of HFI these maps are built only for the SWBs (non polarized) and contain only temperature data, of course. They are not built for the polarisation sensitive detectors because they are not fixed on the sky as the polarisation component depends on the position angle at the time of observation. Instead, we provide maps built by ''quads'' of polarisation-sensitive detectors (see next section), which have different polarisation angles and that can be used to built I, Q, and U maps<br />
<br />
{| border="1" cellpadding="3" cellspacing="0" align="center" style="text-align:left" width=600px<br />
|+ '''HFI Temperature sensitive bolometers'''<br />
|- bgcolor="ffdead" <br />
!Frequency || Detector names<br />
|-<br />
|143 GHz || 143-5, 6, 7<br />
|-<br />
|217 GHz || 217-1, 2, 3, 4<br />
|-<br />
|353 GHz || 353-1, 2, 7, 8<br />
|-<br />
|545 GHz || 545-1, 2, 4<br />
|-<br />
|857 GHz || 857-1, 2 , 3, 4<br />
|}<br />
<br />
The 143-8 and 353-3 bolometer data are affected by strong RTS (random telegraphic signal) noise. They have not been used in the data processing, and are not delivered. For a figure showing the focal plane layout, see [[Detector_pointing#Introduction_and_Summary | this Introduction]] of the Detector Pointing chapter.<br />
<br />
In case of LFI, all the 22 Radiometers maps are available, those, obviously, are only in temperature.<br />
<br />
'''Full mission, detector set or detector pairs maps (8 HFI, 8 LFI)'''<br />
<br />
The objective here is to build independent temperature (I) and polarisation (Q and U) maps with the two pairs of polarisation sensitive detectors of each channel where they are available, i.e. in the 44-353 GHz channels. The table below indicates which detectors were used to built each detector set (detset).<br />
<br />
<br />
{| border="1" cellpadding="3" cellspacing="0" align="center" style="text-align:left" width=600px<br />
|+ '''Definition of HFI Detector Sets'''<br />
|- bgcolor="ffdead" <br />
!Frequency || DetSet1 || DetSet2 <br />
|-<br />
|100 GHz || 100-1a/b & 100-4a/b || 100-2a/b & 100-3a/b<br />
|-<br />
|143 GHz || 143-1a/b 1 & 43-3a/b || 143-2a/b & 143-4a/b<br />
|-<br />
|217 GHz || 217-5a/b & 217-7a/b || 217-6a/b & 217-8a/b<br />
|-<br />
|353 GHz || 353-3a/b & 353-5a/b || 353-4a/b & 353-6a/b<br />
|}<br />
<br />
{| border="1" cellpadding="3" cellspacing="0" align="center" style="text-align:left" width=600px<br />
|+ '''Definition of LFI Detector Pairs'''<br />
|- bgcolor="ffdead" <br />
!Frequency || Horn Pair || Comment <br />
|-<br />
|44 GHz || 24 || This maps is only in temperature<br />
|-<br />
|44 GHz || 25 & 26 || <br />
|-<br />
|70 GHz || 18 & 23 || Available also at <math>N_{side}</math> = 2048<br />
|-<br />
|70 GHz || 19 & 22 || Available also at <math>N_{side}</math> = 2048<br />
|-<br />
|70 GHz || 20 & 21 || Available also at <math>N_{side}</math> = 2048<br />
|}<br />
<br />
<br />
'''Half-ring maps (64 HFI, 62 LFI)'''<br />
<br />
These maps are similar to the ones above, but are built using only the first or the second half of each ring (or pointing period). The HFI provides half-ring maps for the full mission only, and for the full channel, the detsets, and the single bolometers. The LFI provides half-rings maps for the channel full mission (70 GHz also at <math>N_{side}</math> 2048), for the radiometer full mission and the horn pairs full mission.<br />
<!----<br />
'''Masks'''<br />
<br />
Masks are provided of the Galactic Plane and of the point sources. For the Galactic Plane, eight masks are given covering different fractions of the sky, and for the points sources two masks are given, at the 5 and 10 sigma level, for each Planck HFI and LFI frequency channel. These are generic masks, specific masks applicable to other products are delivered with the products themselves.<br />
---><br />
<br />
''' The Zodiacal light correction maps '''<br />
<br />
The Zodiacal light signal depends on the location of the observer relative to the Zodiacal light bands, and thus it is not a fixed pattern on the sky but depends on the period of observation. The maps presented here are the difference between the uncorrected (and not delivered) and the corrected maps. <br />
<br />
Note that while the Zodiacal light model that is subtracted at ring level (see [[Map-making#Zodiacal_light_correction | here]]) is not polarised, the corrections are not null and Q and U. This is suspected to come from some combination of leakage due to bandpass differences and beam mismatch, and maybe other effects. These leakages are typically of order a few %, at max, of the maximum zodi intensity at I for each channel. They range from ~150 nK at 100 GHz to ~5 uK at 353 GHz.<br />
<br />
''' Caveats and known issues '''<br />
<br />
; HFI polarization 100-217 GHz : at low multipoles, despite the progress that has been made to control the systematic effects present in the maps, polarization data between 100-217 GHz are still contaminated by systematic residuals. Figure 10 of {{PlanckPapers|planck2014-a09}} shows the EE power spectra from the half-difference maps at 100, 143, and 217 GHz and compared to the noise power spectrum from FFP8 simulations. he half-ring differences are compatible with noise while, at multipoles typically lower than 50, detector-set and half-mission differences are dominated by excess power which is larger than the EE CMB signal. The Planck Collaboration has used the range ell>30 to carry out component separation ({{PlanckPapers|planck2014-a11}}), as data at ell<30 is not considered usable for cosmological analyses. The origin of the excess power will be explored in a forthcoming publication.<br />
<br />
<br />
'''Inputs'''<br />
''' HFI inputs '''<br />
<br />
The HFI mapmaking takes as input:<br />
* the cleaned TOIs of signal of each detector, together with their flags, produced by the [[TOI processing|TOI processing]] pipeline;<br />
* the TOIs of pointing (quaternions), described in [[Detector_pointing|Detector pointing]];<br />
* bolometer-level characterization data, from the DPC's internal IMO (not distributed);<br />
* Planck orbit data, used to compute and remove the Earth's dipole;<br />
* Planck solar dipole information, used to calibrate the CMB channels;<br />
* Planet models used to calibrate the Galactic channels.<br />
<br />
''' LFI inputs '''<br />
<br />
The Madam mapmaker takes as input:<br />
<br />
* the calibrated timelines (for details see [[TOI processing LFI|TOI Processing]]);<br />
* the detector pointings (for details see [[Detector_pointing|Detector pointing]]);<br />
* the noise information in the form of 3-parameter (white noise level, &sigma;, slope, and knee frequency, <i>f</i><sub>knee</sub>) noise model (for details see [[The RIMO|RIMO]])<br />
<br />
'''Related products'''<br />
''' Masks '''<br />
<br />
This section presents the masks of the point sources and of the Galactic plane. These are ''general purpose'' masks. Other masks specific to certain products are packaged with the products.<br />
<br />
'''Point source masks'''<br />
<br />
For HFI and LFI two sets of masks are provided: <br />
* Intensity masks, which removes sources detected with SNR > 5. <br />
* Polarisation masks, which remove sources which have polarisation detection significance of 99.97 % or greater at the position of a source detected in intensity. They were derived from the polarisation maps with dust ground bandpass mismatch leakage correction applied. The cut around each source has a radius of 3σ (width) of the beam ~ 1.27 FWHM (for LFI the cut around each source has a radius of 32 arcmin at 30GHz, 27 arcmin at 44 GHz and 13 arcmin at 70 GHz).<br />
<br />
Both sets are found in the files ''HFI_Mask_PointSrc_2048_R2.00.fits'' and ''LFI_Mask_PointSrc_2048_R2.00.fits'' in which the first extension contains the Intensity masks, and the second contains the Polarisation masks.<br />
<br />
'''Galactic plane masks'''<br />
<br />
Eight masks are provided giving 20, 40, 60, 70, 80, 90, 97, and 99% sky coverage derived from the 353 GHz map, after CMB subtraction. They are independent of frequency channel. Three versions of these are given: not apodized, and apodized by 2 and 5 deg. The filenames are ''HFI_Mask_GalPlane-apoN_2048_R2.00.fits'', where N = 0, 2, 5.<br />
<br />
The masks are shows below. The 8 GalPlane masks are combined (added together) and shown in a single figure for each of the three apodization. While the result is quite clear for the case of no apodization, it is less so for the apodized case. The point source masks are shown separately for the Intensity case.<br />
<br />
<center><br />
<gallery perrow=3 widths=260px heights=160px ><br />
File: GalPlaneMask_apo0.png | '''Galactic Plane masks, no apod'''<br />
File: GalPlaneMask_apo2.png | '''Galactic Plane masks, apod 2 deg'''<br />
File: GalPlaneMask_apo5.png | '''Galactic Plane masks, apod 5 deg'''<br />
File: PointSrcMask_100.png | '''PointSource mask 100 GHz'''<br />
File: PointSrcMask_143.png | '''PointSource mask 143 GHz'''<br />
File: PointSrcMask_217.png | '''PointSource mask 217 GHz'''<br />
File: PointSrcMask_353.png | '''PointSource mask 343 GHz'''<br />
File: PointSrcMask_545.png | '''PointSource mask 545 GHz'''<br />
File: PointSrcMask_857.png | '''PointSource mask 857 GHz'''<br />
</gallery><br />
</center><br />
<br />
''' File names '''<br />
The FITS filenames are of the form ''{H|L}FI_SkyMap_fff{-tag}_Nside_R2.nn_{coverage}-{type}.fits'', where ''fff'' are three digits to indicate the Planck frequency band, ''tag'' indicates the single detector or the detset, ''Nside'' is the Healpix Nside of the map, ''coverage'' indicates which part of the mission is covered (full, half mission, survey, year, ...) , and the optional ''type'' indicates the subset of input data used. The table below lists the products by type, with the appropriate unix wildcards that form the full filename.<br />
<br />
{| class="wikitable" align="center" style="text-align"left" border="1" cellpadding="15" cellspacing="20" width=880px<br />
|+ '''HFI FITS filenames'''<br />
|- bgcolor="ffdead"<br />
! Coverage || filename || half-ring filename <br />
|-<br />
| Full chan, full mission ||HFI_SkyMap_???_2048_R2.??_full.fits ||HFI_SkyMap_???_2048_R2.??_full-ringhalf-?.fits<br />
|-<br />
| Full channel, nominal mission ||HFI_SkyMap_???_2048_R2.??_nominal.fits || n/a<br />
|-<br />
| Full channel, single survey || HFI_SkyMap_???_2048_R2.??_survey-?.fits || n/a<br />
|-<br />
| Full channel, single year || HFI_SkyMap_???_2048_R2.??_year-?.fits || n/a<br />
|-<br />
| Full channel, half mission || HFI_SkyMap_???_2048_R2.??_halfmission*-?.fits || n/a<br />
|-<br />
| Det-set, full mission || HFI_SkyMap_???-ds?_2048_R2.??_full.fits || HFI_SkyMap_???-ds?_2048_R2.??_full-ringhalf-?.fits<br />
|-<br />
|Single SWB, full mission || HFI_SkyMap_???-?_2048_R2.??_full.fits || HFI_SkyMap_???-?_2048_R2.??_full-ringhalf-?.fits<br />
|}<br />
<br />
{| class="wikitable" align="center" style="text-align"left" border="1" cellpadding="15" cellspacing="20" width=1000px<br />
|+ '''LFI FITS filenames'''<br />
|- bgcolor="ffdead"<br />
! Coverage || filename || half-ring filename || Comment<br />
|-<br />
| Full channel, full mission ||LFI_SkyMap_???_1024_R2.??_full.fits ||LFI_SkyMap_???_1024_R2.??_full-ringhalf-?.fits || Available also at Nside = 2048<br />
|-<br />
| Full channel, single survey || LFI_SkyMap_???_1024_R2.??_survey-?.fits || n/a || Available also at Nside = 2048<br />
|-<br />
| Full channel, survey combination || LFI_SkyMap_???_1024_R2.??_survey-1-3-5-6-7-8.fits || n/a || n/a<br />
|-<br />
| Full channel, single year || LFI_SkyMap_???_1024_R2.??_year-?.fits || n/a || Available also at Nside = 2048<br />
|-<br />
| Full channel, year combination || LFI_SkyMap_???_1024_R2.??_year?-?.fits || n/a || n/a<br />
|-<br />
| Horn pair, full mission || LFI_SkyMap_???-??-??_1024_R2.??_full.fits || LFI_SkyMap_???_??-??_1024_R2.??_full-ringhalf-?.fits || Available also at Nside = 2048<br />
|-<br />
| Single radiometer, full mission || LFI_SkyMap_???-???_1024_R2.??_full.fits || LFI_SkyMap_???-???_1024_R2.??_full-ringhalf-?.fits || n/a<br />
|}<br />
<br />
<br />
<br />
For the benefit of users who are only looking for the frequency maps with no additional information, we also provide a file combining the 9 frequency maps as separate columns in a single extension. The 9 columns in this file contain the intensity maps ONLY and no other information (hit maps and variance maps) is provided.<br />
<br />
<!---<br />
{| class="wikitable" align="center" style="text-align:center" border="1" cellpadding="3" cellspacing="0" width=500px<br />
|+ '''FITS filenames'''<br />
|- bgcolor="ffdead"<br />
! Frequency || Full channel maps<br />
|-<br />
| '''30GHz''' || {{PLASingleFile|fileType=map|name=LFI_SkyMap_030_1024_R1.10_nominal.fits|link=LFI_SkyMap_030_1024_R1.10_nominal.fits}}<br />
|-<br />
| '''44GHz''' || {{PLASingleFile|fileType=map|name=LFI_SkyMap_044_1024_R1.10_nominal.fits|link=LFI_SkyMap_044_1024_R1.10_nominal.fits}}<br />
|-<br />
| '''70GHz''' || {{PLASingleFile|fileType=map|name=LFI_SkyMap_070_1024_R1.10_nominal.fits|link=LFI_SkyMap_070_1024_R1.10_nominal.fits}}<br />
|-<br />
| '''70GHz''' || {{PLASingleFile|fileType=map|name=LFI_SkyMap_070_2048_R1.10_nominal.fits|link=LFI_SkyMap_070_2048_R1.10_nominal.fits}}<br />
|-<br />
| '''100GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_100_2048_R1.10_nominal.fits|link=HFI_SkyMap_100_2048_R1.10_nominal.fits}}<br />
|-<br />
| '''143GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_143_2048_R1.10_nominal.fits|link=HFI_SkyMap_143_2048_R1.10_nominal.fits}}<br />
|-<br />
| '''217GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_217_2048_R1.10_nominal.fits|link=HFI_SkyMap_217_2048_R1.10_nominal.fits}}<br />
|-<br />
| '''353GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_353_2048_R1.10_nominal.fits|link=HFI_SkyMap_353_2048_R1.10_nominal.fits}}<br />
|-<br />
| '''545GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_545_2048_R1.10_nominal.fits|link=HFI_SkyMap_545_2048_R1.10_nominal.fits}}<br />
|-<br />
| '''857GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_857_2048_R1.10_nominal.fits|link=HFI_SkyMap_857_2048_R1.10_nominal.fits}}<br />
|- bgcolor="ffdead"<br />
! Frequency || Full channel, Zodi-corrected maps<br />
|-<br />
| '''100GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_100_2048_R1.10_nominal_ZodiCorrected.fits|link=HFI_SkyMap_100_2048_R1.10_nominal_ZodiCorrected.fits}} <br />
|-<br />
| '''143GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_143_2048_R1.10_nominal_ZodiCorrected.fits|link=HFI_SkyMap_143_2048_R1.10_nominal_ZodiCorrected.fits}}<br />
|-<br />
| '''217GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_217_2048_R1.10_nominal_ZodiCorrected.fits|link=HFI_SkyMap_217_2048_R1.10_nominal_ZodiCorrected.fits}}<br />
|-<br />
| '''353GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_353_2048_R1.10_nominal_ZodiCorrected.fits|link=HFI_SkyMap_353_2048_R1.10_nominal_ZodiCorrected.fits}}<br />
|-<br />
| '''545GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_545_2048_R1.10_nominal_ZodiCorrected.fits|link=HFI_SkyMap_545_2048_R1.10_nominal_ZodiCorrected.fits}}<br />
|-<br />
| '''857GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_857_2048_R1.10_nominal_ZodiCorrected.fits|link=HFI_SkyMap_857_2048_R1.10_nominal_ZodiCorrected.fits}}<br />
|- bgcolor="ffdead"<br />
! Frequency || Combined frequency maps<br />
|-<br />
| '''All''' || {{PLASingleFile|fileType=file|name=COM_MapSet_I-allFreqs_R1.10_nominal.fits|link=COM_MapSet_I-allFreqs_R1.10_nominal.fits}} <br />
|}<br />
<br />
<br />
{| class="wikitable" align="center" style="text-align:center" border="1" cellpadding="3" cellspacing="0" width=850px<br />
|+ '''FITS filenames'''<br />
|- bgcolor="ffdead"<br />
! Frequency || Survey 1 maps || Survey 2 maps<br />
|-<br />
| '''30GHz''' || {{PLASingleFile|fileType=map|name=LFI_SkyMap_030_1024_R1.10_survey_1.fits|link=LFI_SkyMap_030_1024_R1.10_survey_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=LFI_SkyMap_030_1024_R1.10_survey_2.fits|link=LFI_SkyMap_030_1024_R1.10_survey_2.fits}}<br />
|-<br />
| '''44GHz''' || {{PLASingleFile|fileType=map|name=LFI_SkyMap_044_1024_R1.10_survey_1.fits|link=LFI_SkyMap_044_1024_R1.10_survey_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=LFI_SkyMap_044_1024_R1.10_survey_2.fits|link=LFI_SkyMap_044_1024_R1.10_survey_2.fits}}<br />
|-<br />
| '''70GHz''' || {{PLASingleFile|fileType=map|name=LFI_SkyMap_070_1024_R1.10_survey_1.fits|link=LFI_SkyMap_070_1024_R1.10_survey_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=LFI_SkyMap_070_1024_R1.10_survey_2.fits|link=LFI_SkyMap_070_1024_R1.10_survey_2.fits}}<br />
|-<br />
| '''70GHz''' || {{PLASingleFile|fileType=map|name=LFI_SkyMap_070_2048_R1.10_survey_1.fits|link=LFI_SkyMap_070_2048_R1.10_survey_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=LFI_SkyMap_070_2048_R1.10_survey_2.fits|link=LFI_SkyMap_070_2048_R1.10_survey_2.fits}}<br />
|-<br />
| '''100GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_100_2048_R1.10_survey_1.fits|link=HFI_SkyMap_100_2048_R1.10_survey_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_100_2048_R1.10_survey_2.fits|link=HFI_SkyMap_100_2048_R1.10_survey_2.fits}}<br />
|-<br />
| '''143GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_143_2048_R1.10_survey_1.fits|link=HFI_SkyMap_143_2048_R1.10_survey_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_143_2048_R1.10_survey_2.fits|link=HFI_SkyMap_143_2048_R1.10_survey_2.fits}}<br />
|-<br />
| '''217GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_217_2048_R1.10_survey_1.fits|link=HFI_SkyMap_217_2048_R1.10_survey_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_217_2048_R1.10_survey_2.fits|link=HFI_SkyMap_217_2048_R1.10_survey_2.fits}}<br />
|-<br />
| '''353GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_353_2048_R1.10_survey_1.fits|link=HFI_SkyMap_353_2048_R1.10_survey_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_353_2048_R1.10_survey_2.fits|link=HFI_SkyMap_353_2048_R1.10_survey_2.fits}}<br />
|-<br />
| '''545GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_545_2048_R1.10_survey_1.fits|link=HFI_SkyMap_545_2048_R1.10_survey_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_545_2048_R1.10_survey_2.fits|link=HFI_SkyMap_545_2048_R1.10_survey_2.fits}}<br />
|-<br />
| '''857GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_857_2048_R1.10_survey_1.fits|link=HFI_SkyMap_857_2048_R1.10_survey_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_857_2048_R1.10_survey_2.fits|link=HFI_SkyMap_857_2048_R1.10_survey_2.fits}}<br />
|- bgcolor="ffdead"<br />
! Frequency || Survey 1 Zodi-corrected maps || Survey 2 Zodi-corrected maps<br />
|-<br />
| '''100GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_100_2048_R1.10_survey_1_ZodiCorrected.fits|link=HFI_SkyMap_100_2048_R1.10_survey_1_ZodiCorrected.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_100_2048_R1.10_survey_2_ZodiCorrected.fits|link=HFI_SkyMap_100_2048_R1.10_survey_2_ZodiCorrected.fits}}<br />
|-<br />
| '''143GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_143_2048_R1.10_survey_1_ZodiCorrected.fits|link=HFI_SkyMap_143_2048_R1.10_survey_1_ZodiCorrected.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_143_2048_R1.10_survey_2_ZodiCorrected.fits|link=HFI_SkyMap_143_2048_R1.10_survey_2_ZodiCorrected.fits}}<br />
|-<br />
| '''217GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_217_2048_R1.10_survey_1_ZodiCorrected.fits|link=HFI_SkyMap_217_2048_R1.10_survey_1_ZodiCorrected.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_217_2048_R1.10_survey_2_ZodiCorrected.fits|link=HFI_SkyMap_217_2048_R1.10_survey_2_ZodiCorrected.fits}}<br />
|-<br />
| '''353GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_353_2048_R1.10_survey_1_ZodiCorrected.fits|link=HFI_SkyMap_353_2048_R1.10_survey_1_ZodiCorrected.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_353_2048_R1.10_survey_2_ZodiCorrected.fits|link=HFI_SkyMap_353_2048_R1.10_survey_2_ZodiCorrected.fits}}<br />
|-<br />
| '''545GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_545_2048_R1.10_survey_1_ZodiCorrected.fits|link=HFI_SkyMap_545_2048_R1.10_survey_1_ZodiCorrected.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_545_2048_R1.10_survey_2_ZodiCorrected.fits|link=HFI_SkyMap_545_2048_R1.10_survey_2_ZodiCorrected.fits}}<br />
|-<br />
| '''857GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_857_2048_R1.10_survey_1_ZodiCorrected.fits|link=HFI_SkyMap_857_2048_R1.10_survey_1_ZodiCorrected.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_857_2048_R1.10_survey_2_ZodiCorrected.fits|link=HFI_SkyMap_857_2048_R1.10_survey_2_ZodiCorrected.fits}}<br />
|- bgcolor="ffdead"<br />
! Frequency || Half-ring 1 maps ||Half-ring 2 maps<br />
|-<br />
| '''30GHz''' || {{PLASingleFile|fileType=map|name=LFI_SkyMap_030_1024_R1.10_nominal_ringhalf_1.fits|link=LFI_SkyMap_030_1024_R1.10_nominal_ringhalf_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=LFI_SkyMap_030_1024_R1.10_nominal_ringhalf_2.fits|link=LFI_SkyMap_030_1024_R1.10_nominal_ringhalf_2.fits}}<br />
|-<br />
| '''44GHz''' || {{PLASingleFile|fileType=map|name=LFI_SkyMap_044_1024_R1.10_nominal_ringhalf_1.fits|link=LFI_SkyMap_044_1024_R1.10_nominal_ringhalf_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=LFI_SkyMap_044_1024_R1.10_nominal_ringhalf_2.fits|link=LFI_SkyMap_044_1024_R1.10_nominal_ringhalf_2.fits}}<br />
|-<br />
| '''70GHz''' || {{PLASingleFile|fileType=map|name=LFI_SkyMap_070_1024_R1.10_nominal_ringhalf_1.fits|link=LFI_SkyMap_070_1024_R1.10_nominal_ringhalf_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=LFI_SkyMap_070_1024_R1.10_nominal_ringhalf_2.fits|link=LFI_SkyMap_070_1024_R1.10_nominal_ringhalf_2.fits}}<br />
|-<br />
| '''70GHz''' || {{PLASingleFile|fileType=map|name=LFI_SkyMap_070_2048_R1.10_nominal_ringhalf_1.fits|link=LFI_SkyMap_070_2048_R1.10_nominal_ringhalf_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=LFI_SkyMap_070_2048_R1.10_nominal_ringhalf_2.fits|link=LFI_SkyMap_070_2048_R1.10_nominal_ringhalf_2.fits}}<br />
|-<br />
| '''100GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_100_2048_R1.10_nominal_ringhalf_1.fits|link=HFI_SkyMap_100_2048_R1.10_nominal_ringhalf_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_100_2048_R1.10_nominal_ringhalf_2.fits|link=HFI_SkyMap_100_2048_R1.10_nominal_ringhalf_2.fits}}<br />
|-<br />
| '''143GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_143_2048_R1.10_nominal_ringhalf_1.fits|link=HFI_SkyMap_143_2048_R1.10_nominal_ringhalf_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_143_2048_R1.10_nominal_ringhalf_2.fits|link=HFI_SkyMap_143_2048_R1.10_nominal_ringhalf_2.fits}}<br />
|-<br />
| '''217GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_217_2048_R1.10_nominal_ringhalf_1.fits|link=HFI_SkyMap_217_2048_R1.10_nominal_ringhalf_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_217_2048_R1.10_nominal_ringhalf_2.fits|link=HFI_SkyMap_217_2048_R1.10_nominal_ringhalf_2.fits}}<br />
|-<br />
| '''353GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_353_2048_R1.10_nominal_ringhalf_1.fits|link=HFI_SkyMap_353_2048_R1.10_nominal_ringhalf_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_353_2048_R1.10_nominal_ringhalf_2.fits|link=HFI_SkyMap_353_2048_R1.10_nominal_ringhalf_2.fits}}<br />
|-<br />
| '''545GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_545_2048_R1.10_nominal_ringhalf_1.fits|link=HFI_SkyMap_545_2048_R1.10_nominal_ringhalf_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_545_2048_R1.10_nominal_ringhalf_2.fits|link=HFI_SkyMap_545_2048_R1.10_nominal_ringhalf_2.fits}}<br />
|-<br />
| '''857GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_857_2048_R1.10_nominal_ringhalf_1.fits|link=HFI_SkyMap_857_2048_R1.10_nominal_ringhalf_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_857_2048_R1.10_nominal_ringhalf_2.fits|link=HFI_SkyMap_857_2048_R1.10_nominal_ringhalf_2.fits}}<br />
|}<br />
---><br />
<br />
''' FITS file structure '''<br />
<br />
The FITS files for the sky maps contain a minimal primary header with no data, and a ''BINTABLE'' extension (EXTENSION 1, EXTNAME = ''FREQ-MAP'') containing the data. The structure is shows schematically in the figure below. The ''FREQ-MAP'' extension contains a 3- or a 10-column table that contain the signal, hit-count and variance maps, all in Healpix format. The 3-column case is for intensity only maps, the 10-column case is for polarisation. The number of rows is the number of map pixels, which is Npix = 12 <math>N_{side}</math><sup>2</sup> for Healpix maps, where <math>N_{side}</math> = 1024 or 2048 for most the maps presented in this chapter.<br />
<br />
[[File:FITS_FreqMap.png | 550px | center | thumb | '''FITS file structure''']]<br />
<br />
Note that file sizes are ~0.6 GB for I-only maps and ~1.9 GB for I,Q,U maps at <math>N_{side}</math> 2048 and ~0.14 GB for I-only maps and ~0.45 GB for I,Q,U maps at <math>N_{side}</math> 1024 .<br />
<br />
Keywords indicate the coordinate system (GALACTIC), the Healpix ordering scheme (NESTED), the units (K_cmb or MJy/sr) of each column, and of course the frequency channel (FREQ). Where polarisation Q and U maps are provided, the ''COSMO'' polarisation convention (used in HEALPIX) is adopted, and it is specified in the ''POLCCONV'' keyword (see [[Sky_temperature_maps#Polarization_convention_used_in_the_Planck_project|this section]]. The COMMENT fields give a one-line summary of the product, and some other information useful for traceability within the DPCs. The original filename is also given in the ''FILENAME'' keyword. The ''BAD_DATA'' keyword gives the value used by Healpix to indicate pixels for which no signal is present (these will also have a hit-count value of 0). The main parameters are summarised below:<br />
<br />
<br />
{| border="1" cellpadding="3" cellspacing="0" align="center" style="text-align:left" width=800px<br />
|+ '''Sky map file data structure'''<br />
|- bgcolor="ffdead" <br />
!colspan="4" | 1. EXTNAME = 'FREQ-MAP' : Data columns<br />
|- bgcolor="ffdead" <br />
! Column Name || Data Type || Units || Description<br />
|-<br />
|I_STOKES || Real*4 || K_cmb or MJy/sr || The Stokes I map<br />
|-<br />
|Q_STOKES || Real*4 || K_cmb or MJy/sr || The Stokes Q map (optional)<br />
|-<br />
|U_STOKES || Real*4 || K_cmb or MJy/sr || The Stokes U map (optional)<br />
|-<br />
|HITS || Int*4 || none || The hit-count map<br />
|-<br />
|II_COV || Real*4 || K_cmb<sup>2</sup> or (MJy/sr)<sup>2</sup> || The II variance map<br />
|-<br />
|IQ_COV || Real*4 || K_cmb<sup>2</sup> or (MJy/sr)<sup>2</sup> || The IQ variance map (optional)<br />
|-<br />
|IU_COV || Real*4 || K_cmb<sup>2</sup> or (MJy/sr)<sup>2</sup> || The IQ variance map (optional)<br />
|-<br />
|QQ_COV || Real*4 || K_cmb<sup>2</sup> or (MJy/sr)<sup>2</sup> || The QQ variance map (optional)<br />
|-<br />
|QU_COV || Real*4 || K_cmb<sup>2</sup> or (MJy/sr)<sup>2</sup> || The QU variance map (optional)<br />
|-<br />
|UU_COV || Real*4 || K_cmb<sup>2</sup> or (MJy/sr)<sup>2</sup> || The UU variance map (optional)<br />
|-<br />
|- bgcolor="ffdead" <br />
! Keyword || Data Type || Value || Description<br />
|-<br />
|PIXTYPE || string || HEALPIX ||<br />
|-<br />
|COORDSYS || string || GALACTIC ||Coordinate system <br />
|-<br />
|ORDERING || string || NESTED || Healpix ordering<br />
|-<br />
|POLCCONV || String || COSMO || Polarization convention<br />
|-<br />
|NSIDE || Int || 1024 or 2048 || Healpix <math>N_{side}</math> <br />
|-<br />
|FIRSTPIX || Int*4 || 0 || First pixel number<br />
|-<br />
|LASTPIX || Int*4 || 12 <math>N_{side}</math><sup>2</sup> – 1 || Last pixel number<br />
|-<br />
|FREQ || string || nnn || The frequency channel <br />
|}<br />
<br />
<br />
The same structure applies to all ''SkyMap'' products, independent of whether they are full channel, survey of half-ring. The distinction between the types of maps is present in the FITS filename (and in the traceability comment fields).<br />
<br />
'''Polarization convention used in the Planck project'''<br />
<br />
The Planck collaboration used the COSMO convention for the polarization angle (as usually used in space based CMB missions), whereas other astronomical fields usually use the IAU convention. In the following document we report the difference between these two conventions, and the consequence if it is NOT taken into account correctly in the analysis.<br />
<br />
[[File:conventions.png|thumb|center|400px|'''Figure 1. COSMO convention (left) and IAU convention (right). The versor <math>\hat{z}</math> points outwards the pointing direction in COSMO, and inwards in IAU. The bottom panel refers to the plane tangent to the sphere.''']]<br />
<br />
Changing the orientation convention is equivalent to a transformation <math>\psi'=\pi-\psi</math> of the polarization angle (Figure 1). The consequence of this transformation is the inversion of the Stokes parameter <math>U</math>.<br />
The components of the polarization tensor in the helicity basis <math>\epsilon^{\pm}=1/\sqrt{2}(\hat{x}\pm i\hat{y})</math> are:<br />
<br />
<math><br />
(Q+iU)(\hat{n}) = \sum _{\ell m}a_{2,lm}{}_{2}Y_{\ell }^{m}(\hat{n})<br />
\\(Q-iU)(\hat{n}) = \sum _{\ell m}a_{-2,lm}{}_{2}Y_{\ell }^{m}(\hat{n})<br />
</math><br />
<br />
where <math>{}_{2}Y_{\ell }^{m}(\hat{n})</math> are the spin weighted spherical harmonic functions.<br />
The <math>E</math> and <math>B</math> modes can be defined as:<br />
<math><br />
E(\hat{n}) = \sum_{\ell m}a_{E,\ell m}Y_{\ell }^{m}(\hat{n})<br />
\\B(\hat{n}) = \sum_{\ell m}a_{B,\ell m}Y_{\ell }^{m}(\hat{n})<br />
</math><br />
<br />
where the coefficients <math>a_{E,\ell m}</math> and <math>a_{B,\ell m}</math> are derived from linear combinations of the <math>a_{2,\ell m}</math> , <math>a_{-2,\ell m}</math> defined implicitly in the first equation (<math>Q\pm iU</math>).<br />
<br />
[[File:test_gradient.jpg|thumb|center|400px|]]<br />
[[File:test_curl.jpg|thumb|center|400px|'''Figure 2. Error on Planck-LFI 70 GHz <math>EE</math> (top) and <math>BB</math> (bottom) spectra, in case of wrong choice of the coordinate system convention (IAU instead of COSMO).''']]<br />
<br />
The effect of the sign inversion of <math>U</math> on the polarization spectra is a non trivial mixing of <math>E</math> and <math>B</math> modes. <br />
<br />
An example of the typical error on <math>EE</math> and <math>BB</math> auto-spectra in case of a wrong choice of the polarization basis is shown in Figure 2.<br />
<br />
BE CAREFUL about the polarization convention you are using. If the IAU convention is used in computing the power spectra, the sign of the <math>U</math> component of the Planck maps must be inverted before computing <math>E</math> and <math>B</math> modes.<br />
<br />
''' Note on the convention used by the Planck Catalogue of Compact Sources (PCCS) '''<br />
For continuity with other compact sources catolgues, the Catalogue of Compact Sources provided by Planck follows the IAU convention, and the polarization angles are defined on an interval of [-90&deg;,90&deg;]. To switch to the COSMO convention, the polarization angles listed in the catalogue have to be shifted by 90&deg; and multiplied by -1.<br />
<br />
== References ==<br />
<References /><br />
<br />
</div><br />
</div><br />
<br />
<div class="toccolours mw-collapsible mw-collapsed" style="background-color: #EEE8AA;width:80%" ><br />
'''2013 Sky temperature maps'''<br />
<br />
<div class="mw-collapsible-content"><br />
<br />
'''General description'''<br />
<br />
<br />
Sky maps give the best estimate of the intensity of the signal from the sky after removal, as far as possible, of known systematic effects and of the dipole signals induced by the motion of the solar system in the CMB and of the Planck satellite in the solar system. Sky maps are provided for the nominal Planck mission and also, separately, for the first two single surveys, the third one being covered only for a small part during the nominal mission.The details of the start and end times of each are given in [[HFIpreprocessingstatics | this table]]. As a secondary product, maps with estimates of the Zodiacal light and Far-Side-Lobes contribution removed are also provided. <br />
<br />
For characterization purposes, are also provided maps covering the nominal survey but each one using only half of the available data. These are the ''ringhalf_{1|2}'' maps, which are built using the first and second half of the stable pointing part in each pointing period. These maps are used extensively to investigate the (high frequency) noise properties the maps themselves and of other products described elsewhere (see e.g., the [[HFI-Validation | data validation]] section).<br />
<br />
To help in further processing, there are also masks of the Galactic Plane and of point sources, each provided for several different depths.<br />
<br />
All sky maps are in Healpix format, with Nside of 2048 for HFI and of 1024 for LFI (note that the LFI 70 GHz has been delivered also at Nside of 2048 to be directly comparable with HFI maps), in Galactic coordinates, and Nested ordering. The signal is given in units of K<sub>cmb</sub> for 30-353 GHz, and of MJy/sr (for a constant $\nu F_\nu$ energy distribution ) for 545 and 857 GHz. Each sky map is packaged into a ''BINTABLE'' extension of a FITS file together with a hit-count map (or hit map, for short, giving the number of observation samples that are cumulated in a pixel, all detectors combined) and a variance map (determined from the half-ring maps), and additional information is given in the FITS file header. The structure of the FITS file is given in the [[#Format | FITS file structure]] section below.<br />
<br />
<br />
'''Types of maps '''<br />
<br />
; Full channel maps<br />
: Full channel maps are built using all the valid detectors of a frequency channel and cover the nominal mission. For HFI, the 143-8 and 545-3 bolometers are rejected entirely as they are seriously affected by RTS noise. The maps are displayed in the figures below. The range is the same from 30 - 143 GHz in order to show the CMB at the same level. At higher frequencies the range is increased in order to keep the Galactic Plane from invading the whole sky.<br />
<br />
<center><br />
<gallery style="padding:0 0 0 0;" perrow=3 widths=260px heights=160px> <br />
File: SkyMap30.png| '''Nominal mission, 30 GHz'''<br />
File: SkyMap44.png | '''Nominal mission, 44 GHz'''<br />
File: SkyMap70.png | '''Nominal mission, 70 GHz'''<br />
File: SkyMap100.png | '''Nominal mission, 100 GHz'''<br />
File: SkyMap143.png | '''Nominal mission, 143 GHz'''<br />
File: SkyMap217.png | '''Nominal mission, 217 GHz'''<br />
File: SkyMap353.png | '''Nominal mission, 353 GHz'''<br />
File: SkyMap545.png | '''Nominal mission, 545 GHz'''<br />
File: SkyMap857.png | '''Nominal mission, 857 GHz'''<br />
</gallery><br />
</center><br />
<br />
; Single survey maps <br />
: Single survey maps are built using all valid detectors of a frequency channel; they cover separately the different sky surveys. The surveys are defined as the times over which the satellite spin axis rotates but 180 degrees, which, due to the position of the detectors in the focal plane does not cover the full sky, but a fraction between ~80 and 90% depending on detector position.<br />
<br />
; Detector set or detector pairs maps<br />
: These are maps built from a subset of the detectors in a frequency channel, typically our of two PSB pairs (i.e., four poloarisation-sensitive bolometers with different orientation on the sky), for HFI in order to extract a single temperature map. While none of these maps are part of the first Planck data release, the concept of ''detset'' is used, and thus it is worth mentioning it here. In particular, information by detector set is available at the [[Frequency_maps_angular_power_spectra | sky power spectrum]] level and in the [[The RIMO | RIMO]].<br />
<br />
; Half-ring maps<br />
: Half-ring maps are built using only the first or the second half of the stable pointing period data. There are thus two half-ring maps per frequency channel named ''ringhalf_1'' and ''ringhalf_2'' respectively. These maps are built for characterization purposes in order to perform null tests. In particular, the difference between the two half-ring maps at a given frequency give a good estimate of the high frequency noise in the data (albeit biased low by ~0.5% for the HFI channels due to specifics of the TOI processing).<br />
<br />
; Masks<br />
: Masks are provided of the Galactic Plane and of the point sources. For the Galactic Plane, eight masks are given covering different fractions of the sky, and for the points sources two masks are given, at the 5 and 10 sigma level, for each Planck HFI frequency channel. These are generic masks, specific masks applicable to other products are delivered with the products themselves.<br />
<br />
''' Caveats and known issues'''<br />
<br />
The primary limitation of the HFI maps are<br />
* the absence of correction of the ADC non-linearities,<br />
* the far-side lobe contribution is not accounted for in the processing and in the calibration,<br />
* the dipole removal is based on the non-relativistic approximation which leaves a weak quadrupole component in the map.<br />
And thus the overall calibration accuracy is at the 0.2% level in 100-217 GHz channels<br />
<br />
The LFI 70 GHz maps at Nside=2048 should be considered as additional product, the default are the LFI maps at Nside=1024. No effective beam at Nside=2048 is provided, only at Nside=1024, for this reason the use of the effective beam with maps at Nside 2048 is discouraged.<br />
<br />
''' Map zero-level '''<br />
<br />
For the 100 to 857 GHz maps, the zero levels are set to their optimal levels for Galactic and CIB studies. A procedure for adjusting them to astrophysical values is given in the HFI Calibration paper {{PlanckPapers|planck2013-p03b}}.<br />
<br />
For the 30, 44 and 70 GHz, maps are corrected for zero level monopole by applying an offset correction, see LFI Calibration paper {{PlanckPapers|planck2013-p02b}} section 3.4 "Setting the zero levels in the maps". Note that the offset applied is indicated in the header as a comment keyword.<br />
<br />
''' The Zodiacal light and the Far-Side Lobes '''<br />
<br />
The figures below show the modeled Zodiacal light and Far Side Lobes projected onto the maps; they are simply the difference between the ''main product'' and the ''ZodiCorrected'' maps for the nominal mission. The units are given in the figures. The ''heat'' color table has been used in place of the standard Planck for clarity reasons. <br />
<center><br />
<gallery perrow=3 widths=260px heights=170px><br />
File: ZodiRes100.png | '''zodi/FSL rediduals - 100 GHz'''<br />
File: ZodiRes143.png | '''zodi/FSL rediduals - 143 GHz''' <br />
File: ZodiRes217.png | '''zodi/FSL rediduals - 217 GHz'''<br />
File: ZodiRes353.png | '''zodi/FSL rediduals - 353 GHz'''<br />
File: ZodiRes545.png | '''zodi/FSL rediduals - 545 GHz'''<br />
File: ZodiRes857.png | '''zodi/FSL rediduals - 857 GHz'''<br />
</gallery><br />
</center><br />
The effects of the FSLs are seen most clearly at the highest frequencies, as structures roughly symmetric about the center of the image, which corresponds to the location of the Galactic Centre, which is in turn the source of most of the radiation that is scattered into the FSLs.<br />
<br />
''' Artifacts near caustics of the scanning strategy '''<br />
<br />
The [[Survey scanning and performance|scanning strategy]] is such that regions around the Ecliptic poles are surveyed very deeply and compared to the average, and the transition from the nominal depth to the high depth, as shows on hit-count maps is very rapid, namely a few pixels, for a contrast of ~30. These transitions, or caustics in the maps, occur at different positions on the sky for different detectors, as the positions depend on their location in the focal plane of the instrument. As a result, when data from different detectors are combined to build a full channel map, the the weights of different detectors in the mix changes rapidly across the caustic, and given the remaining errors in the relative calibration of the detectors, a visible effect can be introduced in the maps, especially when the SNR is very high, i.e. at the highest frequencies and near bright regions like the Galactic Plane. Some examples are shown below.<br />
<br />
<center><br />
<gallery perrow=3 heights=260px widths=260pix ><br />
File: causta857.png | '''857 GHz intensity map around (272.5, -27)'''<br />
File: caustb857.png | '''857 GHz intensity map around (264.5, -37.5)'''<br />
File: caustc857.png | '''857 GHz intensity map around (98.5, 43)'''<br />
File: hita857.png | '''857 GHz hit count map around (272.5, -27)'''<br />
File: hitb857.png | '''857 GHz hit count map around (264.5, -37.5)'''<br />
File: hitc857.png | '''857 GHz hit count map around (98.5, 43)'''<br />
</gallery><br />
</center><br />
<br />
'''Production process'''<br />
<br />
<br />
Sky maps are produced by combining appropriately the data of all working detectors in a frequency channel over some period of the mission. They give the best estimate of the signal from the sky (unpolarised) after removal, as far as possible, of known systematic effects and of the dipole signals induced by the motion of the solar system in the CMB and of the Planck satellite in the solar system. In particular, they include the Zodiacal light emission (Zodi for short) and also the scattering from the far-side lobes of the beams (FSL). More on this below.<br />
<br />
''' HFI processing '''<br />
<br />
The inputs to the mapmaking are TOIs of signal that have been cleaned (as far as possible) of instrumental effects and calibrated in absorbed watts. While the processing involved is described in detail in the [[TOI processing|TOI processing]] section, we give a very brief summary here for convenience. That pipeline performs the following operations:<br />
<br />
; demodulation: this is performed around a variable level which is determined from the valid input data (a validity flag from a previous version of the processing is used for this purpose), and the data are converted to engineering units (V) using known conversion coefficients.<br />
; despiking: using the demodulated data converted to V (by the transfer function) the glitches are identified and fitted with templates. A glitch flag is produced that identifies the strongest part of the glitches, and a timeline of glitch tails is produced from the template fits, and subtracted from the demodulated timeline from step 1. Finally, the flagged ranges are replaced with data from an average over the pointing period (TBC)<br />
; dark template removal: the two dark bolometers are demodulated and despiked as above; the resulting timelines are then smoothed and used as an indicator of the overall temperature variations of the bolometer plate. Where the variations are consistent with each other, they are combined and removed from the bolometer signal timelines using appropriate coupling coefficients. The few percent of the data where they are not consistent are flagged on the timelines.<br />
; conversion to absorbed power: the timeline is converted to watts of absorbed power using the bolometer function. This includes a non-linearity correction; removal of the 4K cooler lines: the electromagnetic interference of the 4K cooler with the bolometer readout wires induces some sharp lines in the signal power spectra at frequencies of the 4K cooler's fundamental and its multiples, folded by the signal modulations. Fourier coefficients of the relevant lines are determined on a per-ring basis, and then removed from the data. The quality of the removal depends on the bolometer.<br />
; deconvolution by the time transfer function: this is done to correct for the non-instantaneous time response of the bolometers. The function itself is modeled using 4 parameters which are adjusted primarily on the planet data and also from comparisons of the northward and southward scans of the Galactic Plane. It is then removed using Fourier techniques, which has the side-effect of increasing the noise at high frequencies.<br />
; jump correction: removes some (relatively rare: 0.3 jumps per bolometer per pointing period, on average) jumps in the signal baseline. The jumps are detected characterized on smoothed TOIs, and corrected by adding a constant to part of the signal timeline. The origin of the jumps is not known.<br />
<br />
The results of this processing are a timeline of signal (in absorbed watts) and a ''valid data'' flag timeline for each of the 50 valid bolometers processed; these timelines contain the full sky signal, i.e., including the solar and orbital dipoles, the Zodiacal light, and contributions from the Far-Side lobes. The dipoles are necessary for the flux calibration and are removed at the mapmaking stage. The remaining two bolometers (143-8 and 535-3) show semi-random jumps in the signal level, typically jumping over 2-5 different ''pseudo-baseline'' levels, a behavior known as ''Random Telegraphic Signal'', so that these are commonly called the RTS bolometers. Finally, ring-level statistics of different types (mean, median, rms, kurtosis, etc.) are determined on a per-ring basis for all timelines, and a selection based on these statistics is used to discard anomalous rings, which are recorded in a ring-level flag for each valid bolometer timeline (see the [[TOI_processing#Discarded_rings| Discarded rings]] section). <br />
<br />
Throughout this processing, bright planets (Mars, Jupiter, Saturn, Uranus) and bright asteroids are masked in the timeline in order to avoid ringing effects in the processing. Since they move on the sky, the portion of the sky masked during one survey is observed during one, and no hole is left in the final map. In parallel, the planet data are processed in a similar way, but with different parameters for the despiking step, and without the final jump correction step. These results are processed separately to determine the beam shapes and the focal plane geometry.<br />
<br />
The pointing is determined starting from the AHF produced by MOC, which gives the direction and orientation of the LOS of a fiducial position in the focal plane at frequencies of 8Hz during stable pointing and 4 Hz during maneuvers (TBC for details, reference). This is interpolated to the times of data observation (ref to method), corrected for the wobble and other time-dependent offsets determined from the observed positions of a large number of sources around the sky, and finally converted to the LOS of each detector using the quaternions in the IMO (which are determined from observations of bright planets - see the [[Detector_pointing]] section). <br />
<br />
The mapmaking and calibration process is described in detail in the [[Map-making_LFI | Map-making]] section, where detailed references are found. In brief it consists of:<br />
<br />
; binning the TOI data onto ''rings'' : Healpix rings (HPRs) are used here, each ring containing the combined data of one pointing period. <br />
; flux calibration : at 100-353 GHz, the flux calibration factors are determined for each pointing period (or ring) from the solar-motion dipole, using the WMAP dipole as the reference, and after removal of the dipole signal induced by the motion of the Planck satellite in the solar system. This gain by ring is smoothed with a window of width 50 rings, which reveals an apparent variation of ~1-2% on a scale of 100s to 1000s of rings for the 100-217 GHz channels, and is applied. At 353GHz, where the solar motion dipole is weaker compared to the signal, no gain variation is detected (within the uncertainties), and a single fixed gain is applied to all rings. At 545 and 857 GHz the gain is determined from the observation of Uranus and Neptune (but not Jupiter which is too bright) and comparison to recent models made explicitly for this mission. A single gain is applied to all rings at these frequencies.<br />
; destriping : in order to remove low-frequency noise, an offset per ring is determined by minimizing the differences between HPRs at their crossings, and removed.<br />
; projection onto the map : the offset-corrected and flux-calibrated HPRs are projected onto Healpix maps, with the data of each bolometer weighted by a factor of 1/NET of that bolometer, and accounting for the slight different band transmission profiles of the bolometers in each band. <br />
<br />
These maps provide the main mission products. A second, reduced, set of maps, cleaned of the Zodiacal emission of the FSL leakage is also produced for the nominal mission and the two single surveys, but not for the half-rings (since the contribution would be the same for the two halves of each ring). For this purpose, the the Zodiacal emission and the FSL contamination, which are not fixed on the sky, are modeled separately at HPR-level, and subtracted from the signal HPR before projecting them onto the maps. <br />
<br />
Together with signal maps, hit count and variance maps are also produced. The hit maps give the (integer) number of valid TOI-level samples that contribute to the signal of each pixel. All valid samples are counted in the same way, i.e., there is no weighting factor applied. The variance maps project the white noise estimate, provided by the NETs, in the sky domain.<br />
<br />
''' LFI processing '''<br />
<br />
LFI maps were constructed with the Madam map-making code, version 3.7.4. The code is based on generalized destriping technique, where the correlated noise component is modeled as a sequence of constant offset, called baselines. A noise filter was used to constrain the baseline solution allowing the use of 1 second baselines.<br />
<br />
Radiometers were combined according to the horn-uniform weighting scheme to minimize systematics. The used weights are listed in [[Map-making LFI#Map-making|Map-making]]. The flagged samples were excluded from the analysis by setting their weights to $C_{w}^{-1}$ = 0. The galaxy region was masked out in the destriping phase, to reduce error arising from strong signal gradients. The polarization component was included in the analysis, although only the temperature maps are released. <br />
<br />
A detailed description of the map-making procedure is given in {{PlanckPapers|planck2013-p02}} and in section [[Map-making LFI#Map-making|Map-making]].<br />
<br />
'''Inputs'''<br />
<br />
<br />
''' HFI inputs '''<br />
<br />
* The cleaned TOIs of signal of each detector, together with their flags, produced by the [[TOI processing|TOI processing]] pipeline<br />
* The TOIs of pointing (quaternions), described in [[Detector_pointing]]<br />
* Bolometer-level characterization data, from the DPC's internal IMO (not distributed)<br />
* Planck orbit data used to compute and remove the earth dipole<br />
* WMAP solar dipole information used to calibrate the CMB channels<br />
* Planet models used to calibrate the Galactic channels.<br />
<br />
''' LFI inputs '''<br />
<br />
The Madam map-maker takes as an input:<br />
<br />
* The calibrated timelines (for details see [[TOI processing LFI|TOI Processing]])<br />
* The detector pointings (for details see [[Detector pointing|Detector pointing]])<br />
* The noise information in the form of three-parameter (white noise level ($\sigma$), slope, and knee frequency ($f_\mathrm{knee}$)) noise model (for details see [[The RIMO|RIMO]])<br />
<br />
'''Related products'''<br />
<br />
<br />
''' Masks '''<br />
<br />
Masks are provided of<br />
<br />
; the point sources<br />
: 15 masks are provided, three for the LFI (one mask for each frequency masking at the 4<math>\sigma</math> level) and 12 for the HFI (two masks for each frequency at the 5 and 10<math>\sigma</math> levels. For the HFI the masks can be used as they are, for the LFI they need to be downgraded to Nside=1024 except for the 70 GHz channel at Nside=2048 which does not need to be downgraded.<br />
<br />
; the Galactic Plane<br />
: 8 masks are provided giving 20, 40, 60, 70, 80, 90, 97, and 99% sky coverage in two different files, at Nside=2048. For the HFI they can be used as they are, for the LFI they need to be downgraded at Nside=1024 (note that if using the 70 GHZ at Nside=2048 no downgraded is needed)<br />
<br />
<br />
The masks are binary, in GALACTIC coordinates, and NESTED ordering. The table below give the filenames. <br />
<br />
<br />
{| class="wikitable" align="center" style="text-align:center" border="1" cellpadding="5" cellspacing="0" <br />
|+ '''FITS filenames for masks'''<br />
|-bgcolor="ffdead"<br />
! Frequency || LFI Point Source masks<br />
|-<br />
| '''30GHz''' || {{PLASingleFile|fileType=map|name=LFI_MASK_030-ps_2048_R1.00.fits|link=LFI_MASK_030-ps_2048_R1.00.fits}}<br />
|-<br />
| '''44GHz''' || {{PLASingleFile|fileType=map|name=LFI_MASK_044-ps_2048_R1.00.fits|link=LFI_MASK_044-ps_2048_R1.00.fits}}<br />
|-<br />
| '''70GHz''' || {{PLASingleFile|fileType=map|name=LFI_MASK_070-ps_2048_R1.00.fits|link=LFI_MASK_070-ps_2048_R1.00.fits}}<br />
|- bgcolor="ffdead"<br />
! colspan="2" | HFI Point Source masks<br />
|-<br />
| colspan="2" | {{PLASingleFile|fileType=map|name=HFI_Mask_PointSrc_2048_R1.10.fits|link=HFI_Mask_PointSrc_2048_R1.10.fits}}<br />
|- bgcolor="ffdead"<br />
! colspan="2" | Galactic Plane masks<br />
|-<br />
| colspan="2" | {{PLASingleFile|fileType=map|name=HFI_Mask_GalPlane_2048_R1.10.fits|link=HFI_Mask_GalPlane_2048_R1.10.fits}} <br />
|}<br />
<br />
<br />
The masks are shows below in a single figure. While this is quite clear for the Galactic Plane masks, it is less so for the point source masks, but it does give a clear perspective on how the latter are distributed over the sky.<br />
<br />
<center><br />
<gallery perrow=2 widths=300px heights=185px ><br />
File: HFI_GalPlaneMask.png | '''Galactic Plane masks'''<br />
File: HFI_PointSrcMask.png | '''PointSource masks'''<br />
</gallery><br />
</center><br />
<br />
''' File names '''<br />
<br />
<br />
The FITS filenames are of the form ''{H|L}FI_SkyMap_fff_nnnn_R1.nn_{coverage}_{type}.fits'', where ''fff'' are three digits to indicate the Planck frequency band, and ''nnnn'' is the Healpix Nside of the map, ''coverage'' indicates which part of the mission is covered, and the optional ''type'' indicates the subset of input data used. A full list of products, with links to them in the Archive, is given in the tables below.<br />
<br />
For the benefit of users who are only looking for the frequency maps with no additional information, we also provide a file combining the 9 frequency maps as separate columns in a single extension. The 9 columns in this file contain the intensity maps ONLY and no other information (hit maps and variance maps) is provided.<br />
<br />
{| class="wikitable" align="center" style="text-align:center" border="1" cellpadding="5" cellspacing="0" width=500px<br />
|+ '''FITS filenames'''<br />
|- bgcolor="ffdead"<br />
! Frequency || Full channel maps<br />
|-<br />
| '''30GHz''' || {{PLASingleFile|fileType=map|name=LFI_SkyMap_030_1024_R1.10_nominal.fits|link=LFI_SkyMap_030_1024_R1.10_nominal.fits}}<br />
|-<br />
| '''44GHz''' || {{PLASingleFile|fileType=map|name=LFI_SkyMap_044_1024_R1.10_nominal.fits|link=LFI_SkyMap_044_1024_R1.10_nominal.fits}}<br />
|-<br />
| '''70GHz''' || {{PLASingleFile|fileType=map|name=LFI_SkyMap_070_1024_R1.10_nominal.fits|link=LFI_SkyMap_070_1024_R1.10_nominal.fits}}<br />
|-<br />
| '''70GHz''' || {{PLASingleFile|fileType=map|name=LFI_SkyMap_070_2048_R1.10_nominal.fits|link=LFI_SkyMap_070_2048_R1.10_nominal.fits}}<br />
|-<br />
| '''100GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_100_2048_R1.10_nominal.fits|link=HFI_SkyMap_100_2048_R1.10_nominal.fits}}<br />
|-<br />
| '''143GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_143_2048_R1.10_nominal.fits|link=HFI_SkyMap_143_2048_R1.10_nominal.fits}}<br />
|-<br />
| '''217GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_217_2048_R1.10_nominal.fits|link=HFI_SkyMap_217_2048_R1.10_nominal.fits}}<br />
|-<br />
| '''353GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_353_2048_R1.10_nominal.fits|link=HFI_SkyMap_353_2048_R1.10_nominal.fits}}<br />
|-<br />
| '''545GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_545_2048_R1.10_nominal.fits|link=HFI_SkyMap_545_2048_R1.10_nominal.fits}}<br />
|-<br />
| '''857GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_857_2048_R1.10_nominal.fits|link=HFI_SkyMap_857_2048_R1.10_nominal.fits}}<br />
|- bgcolor="ffdead"<br />
! Frequency || Full channel, Zodi-corrected maps<br />
|-<br />
| '''100GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_100_2048_R1.10_nominal_ZodiCorrected.fits|link=HFI_SkyMap_100_2048_R1.10_nominal_ZodiCorrected.fits}} <br />
|-<br />
| '''143GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_143_2048_R1.10_nominal_ZodiCorrected.fits|link=HFI_SkyMap_143_2048_R1.10_nominal_ZodiCorrected.fits}}<br />
|-<br />
| '''217GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_217_2048_R1.10_nominal_ZodiCorrected.fits|link=HFI_SkyMap_217_2048_R1.10_nominal_ZodiCorrected.fits}}<br />
|-<br />
| '''353GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_353_2048_R1.10_nominal_ZodiCorrected.fits|link=HFI_SkyMap_353_2048_R1.10_nominal_ZodiCorrected.fits}}<br />
|-<br />
| '''545GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_545_2048_R1.10_nominal_ZodiCorrected.fits|link=HFI_SkyMap_545_2048_R1.10_nominal_ZodiCorrected.fits}}<br />
|-<br />
| '''857GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_857_2048_R1.10_nominal_ZodiCorrected.fits|link=HFI_SkyMap_857_2048_R1.10_nominal_ZodiCorrected.fits}}<br />
|- bgcolor="ffdead"<br />
! Frequency || Combined frequency maps<br />
|-<br />
| '''All''' || {{PLASingleFile|fileType=file|name=COM_MapSet_I-allFreqs_R1.10_nominal.fits|link=COM_MapSet_I-allFreqs_R1.10_nominal.fits}} <br />
|}<br />
<br />
<br />
{| class="wikitable" align="center" style="text-align:center" border="1" cellpadding="5" cellspacing="0" width=850px<br />
|+ '''FITS filenames'''<br />
|- bgcolor="ffdead"<br />
! Frequency || Survey 1 maps || Survey 2 maps<br />
|-<br />
| '''30GHz''' || {{PLASingleFile|fileType=map|name=LFI_SkyMap_030_1024_R1.10_survey_1.fits|link=LFI_SkyMap_030_1024_R1.10_survey_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=LFI_SkyMap_030_1024_R1.10_survey_2.fits|link=LFI_SkyMap_030_1024_R1.10_survey_2.fits}}<br />
|-<br />
| '''44GHz''' || {{PLASingleFile|fileType=map|name=LFI_SkyMap_044_1024_R1.10_survey_1.fits|link=LFI_SkyMap_044_1024_R1.10_survey_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=LFI_SkyMap_044_1024_R1.10_survey_2.fits|link=LFI_SkyMap_044_1024_R1.10_survey_2.fits}}<br />
|-<br />
| '''70GHz''' || {{PLASingleFile|fileType=map|name=LFI_SkyMap_070_1024_R1.10_survey_1.fits|link=LFI_SkyMap_070_1024_R1.10_survey_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=LFI_SkyMap_070_1024_R1.10_survey_2.fits|link=LFI_SkyMap_070_1024_R1.10_survey_2.fits}}<br />
|-<br />
| '''70GHz''' || {{PLASingleFile|fileType=map|name=LFI_SkyMap_070_2048_R1.10_survey_1.fits|link=LFI_SkyMap_070_2048_R1.10_survey_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=LFI_SkyMap_070_2048_R1.10_survey_2.fits|link=LFI_SkyMap_070_2048_R1.10_survey_2.fits}}<br />
|-<br />
| '''100GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_100_2048_R1.10_survey_1.fits|link=HFI_SkyMap_100_2048_R1.10_survey_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_100_2048_R1.10_survey_2.fits|link=HFI_SkyMap_100_2048_R1.10_survey_2.fits}}<br />
|-<br />
| '''143GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_143_2048_R1.10_survey_1.fits|link=HFI_SkyMap_143_2048_R1.10_survey_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_143_2048_R1.10_survey_2.fits|link=HFI_SkyMap_143_2048_R1.10_survey_2.fits}}<br />
|-<br />
| '''217GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_217_2048_R1.10_survey_1.fits|link=HFI_SkyMap_217_2048_R1.10_survey_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_217_2048_R1.10_survey_2.fits|link=HFI_SkyMap_217_2048_R1.10_survey_2.fits}}<br />
|-<br />
| '''353GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_353_2048_R1.10_survey_1.fits|link=HFI_SkyMap_353_2048_R1.10_survey_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_353_2048_R1.10_survey_2.fits|link=HFI_SkyMap_353_2048_R1.10_survey_2.fits}}<br />
|-<br />
| '''545GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_545_2048_R1.10_survey_1.fits|link=HFI_SkyMap_545_2048_R1.10_survey_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_545_2048_R1.10_survey_2.fits|link=HFI_SkyMap_545_2048_R1.10_survey_2.fits}}<br />
|-<br />
| '''857GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_857_2048_R1.10_survey_1.fits|link=HFI_SkyMap_857_2048_R1.10_survey_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_857_2048_R1.10_survey_2.fits|link=HFI_SkyMap_857_2048_R1.10_survey_2.fits}}<br />
|- bgcolor="ffdead"<br />
! Frequency || Survey 1 Zodi-corrected maps || Survey 2 Zodi-corrected maps<br />
|-<br />
| '''100GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_100_2048_R1.10_survey_1_ZodiCorrected.fits|link=HFI_SkyMap_100_2048_R1.10_survey_1_ZodiCorrected.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_100_2048_R1.10_survey_2_ZodiCorrected.fits|link=HFI_SkyMap_100_2048_R1.10_survey_2_ZodiCorrected.fits}}<br />
|-<br />
| '''143GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_143_2048_R1.10_survey_1_ZodiCorrected.fits|link=HFI_SkyMap_143_2048_R1.10_survey_1_ZodiCorrected.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_143_2048_R1.10_survey_2_ZodiCorrected.fits|link=HFI_SkyMap_143_2048_R1.10_survey_2_ZodiCorrected.fits}}<br />
|-<br />
| '''217GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_217_2048_R1.10_survey_1_ZodiCorrected.fits|link=HFI_SkyMap_217_2048_R1.10_survey_1_ZodiCorrected.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_217_2048_R1.10_survey_2_ZodiCorrected.fits|link=HFI_SkyMap_217_2048_R1.10_survey_2_ZodiCorrected.fits}}<br />
|-<br />
| '''353GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_353_2048_R1.10_survey_1_ZodiCorrected.fits|link=HFI_SkyMap_353_2048_R1.10_survey_1_ZodiCorrected.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_353_2048_R1.10_survey_2_ZodiCorrected.fits|link=HFI_SkyMap_353_2048_R1.10_survey_2_ZodiCorrected.fits}}<br />
|-<br />
| '''545GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_545_2048_R1.10_survey_1_ZodiCorrected.fits|link=HFI_SkyMap_545_2048_R1.10_survey_1_ZodiCorrected.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_545_2048_R1.10_survey_2_ZodiCorrected.fits|link=HFI_SkyMap_545_2048_R1.10_survey_2_ZodiCorrected.fits}}<br />
|-<br />
| '''857GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_857_2048_R1.10_survey_1_ZodiCorrected.fits|link=HFI_SkyMap_857_2048_R1.10_survey_1_ZodiCorrected.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_857_2048_R1.10_survey_2_ZodiCorrected.fits|link=HFI_SkyMap_857_2048_R1.10_survey_2_ZodiCorrected.fits}}<br />
|- bgcolor="ffdead"<br />
! Frequency || Half-ring 1 maps ||Half-ring 2 maps<br />
|-<br />
| '''30GHz''' || {{PLASingleFile|fileType=map|name=LFI_SkyMap_030_1024_R1.10_nominal_ringhalf_1.fits|link=LFI_SkyMap_030_1024_R1.10_nominal_ringhalf_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=LFI_SkyMap_030_1024_R1.10_nominal_ringhalf_2.fits|link=LFI_SkyMap_030_1024_R1.10_nominal_ringhalf_2.fits}}<br />
|-<br />
| '''44GHz''' || {{PLASingleFile|fileType=map|name=LFI_SkyMap_044_1024_R1.10_nominal_ringhalf_1.fits|link=LFI_SkyMap_044_1024_R1.10_nominal_ringhalf_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=LFI_SkyMap_044_1024_R1.10_nominal_ringhalf_2.fits|link=LFI_SkyMap_044_1024_R1.10_nominal_ringhalf_2.fits}}<br />
|-<br />
| '''70GHz''' || {{PLASingleFile|fileType=map|name=LFI_SkyMap_070_1024_R1.10_nominal_ringhalf_1.fits|link=LFI_SkyMap_070_1024_R1.10_nominal_ringhalf_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=LFI_SkyMap_070_1024_R1.10_nominal_ringhalf_2.fits|link=LFI_SkyMap_070_1024_R1.10_nominal_ringhalf_2.fits}}<br />
|-<br />
| '''70GHz''' || {{PLASingleFile|fileType=map|name=LFI_SkyMap_070_2048_R1.10_nominal_ringhalf_1.fits|link=LFI_SkyMap_070_2048_R1.10_nominal_ringhalf_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=LFI_SkyMap_070_2048_R1.10_nominal_ringhalf_2.fits|link=LFI_SkyMap_070_2048_R1.10_nominal_ringhalf_2.fits}}<br />
|-<br />
| '''100GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_100_2048_R1.10_nominal_ringhalf_1.fits|link=HFI_SkyMap_100_2048_R1.10_nominal_ringhalf_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_100_2048_R1.10_nominal_ringhalf_2.fits|link=HFI_SkyMap_100_2048_R1.10_nominal_ringhalf_2.fits}}<br />
|-<br />
| '''143GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_143_2048_R1.10_nominal_ringhalf_1.fits|link=HFI_SkyMap_143_2048_R1.10_nominal_ringhalf_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_143_2048_R1.10_nominal_ringhalf_2.fits|link=HFI_SkyMap_143_2048_R1.10_nominal_ringhalf_2.fits}}<br />
|-<br />
| '''217GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_217_2048_R1.10_nominal_ringhalf_1.fits|link=HFI_SkyMap_217_2048_R1.10_nominal_ringhalf_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_217_2048_R1.10_nominal_ringhalf_2.fits|link=HFI_SkyMap_217_2048_R1.10_nominal_ringhalf_2.fits}}<br />
|-<br />
| '''353GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_353_2048_R1.10_nominal_ringhalf_1.fits|link=HFI_SkyMap_353_2048_R1.10_nominal_ringhalf_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_353_2048_R1.10_nominal_ringhalf_2.fits|link=HFI_SkyMap_353_2048_R1.10_nominal_ringhalf_2.fits}}<br />
|-<br />
| '''545GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_545_2048_R1.10_nominal_ringhalf_1.fits|link=HFI_SkyMap_545_2048_R1.10_nominal_ringhalf_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_545_2048_R1.10_nominal_ringhalf_2.fits|link=HFI_SkyMap_545_2048_R1.10_nominal_ringhalf_2.fits}}<br />
|-<br />
| '''857GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_857_2048_R1.10_nominal_ringhalf_1.fits|link=HFI_SkyMap_857_2048_R1.10_nominal_ringhalf_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_857_2048_R1.10_nominal_ringhalf_2.fits|link=HFI_SkyMap_857_2048_R1.10_nominal_ringhalf_2.fits}}<br />
|}<br />
<br />
''' FITS file structure '''<br />
<br />
<br />
[[File:FITS_FreqMap.png | 500px | right | thumb | '''FITS file structure''']]<br />
<br />
The FITS files for the sky maps contain a minimal primary header with no data, and a ''BINTABLE'' extension (EXTENSION 1, EXTNAME = ''FREQ-MAP'') containing the data. The structure is shows schematically in the figure at right. <br />
<br />
The ''FREQ-MAP'' extension contains is a 3-column table that contain the signal, hit-count and variance maps, all in Healpix format, in columns 1, 2, and 3, respectively. The number of rows is 50331648 for HFI and LFI 70 GHz at Nside=2048 and 12582912 for LFI maps at Nside=1024 (N.B: Npix = 12 Nside^2). The three columns are ''I_STOKES'' for the intensity (or temperature) signal, ''HIT'' for the hit-count and ''II_COV'' for the variance. The exact order of the columns in the figure is indicative only, and the details can be found in the keywords. <br />
<br />
Keywords indicate the coordinate system (GALACTIC), the Healpix ordering scheme (NESTED), the units (K_cmb or MJy/sr) of each column, and of course the frequency channel (FREQ). The COMMENT fields give a one-line summary of the product, and some other information useful for traceability within the DPCs. The original filename is also given in the ''FILENAME'' keyword as are the datasum and the md5 checksum for the extension. The ''BAD_DATA'' keyword gives the value used by Healpix to indicate pixels for which no signal is present (these will also have a hit-count value of 0). The COMMENT fields give further information including some traceability data for the DPC's. The main parameters are summarised below:<br />
<br />
<br />
{| border="1" cellpadding="3" cellspacing="0" align="center" style="text-align:left" width=800px<br />
|+ '''Sky map file data structure'''<br />
|- bgcolor="ffdead" <br />
!colspan="4" | 1. EXTNAME = 'FREQ-MAP' : Data columns<br />
|- bgcolor="ffdead" <br />
! Column Name || Data Type || Units || Description<br />
|-<br />
|I_STOKES || Real*4 || K_cmb or MJy/sr || The signal map<br />
|-<br />
|HITS || Int*4 || none || The hit-count map<br />
|-<br />
|II_COV || Real*4 || K_cmb<sup>2</sup> or (MJy/sr)<sup>2</sup> || The variance map<br />
|- bgcolor="ffdead" <br />
! Keyword || Data Type || Value || Description<br />
|-<br />
|PIXTYPE || string || HEALPIX ||<br />
|-<br />
|COORDSYS || string || GALACTIC ||Coordinate system <br />
|-<br />
|ORDERING || string || NESTED || Healpix ordering<br />
|-<br />
|NSIDE || Int || 1024 or 2048 || Healpix Nside <br />
|-<br />
|FIRSTPIX || Int*4 || 0 || First pixel number<br />
|-<br />
|LASTPIX || Int*4 || 12582911 or 50331647 || Last pixel number<br />
|-<br />
|FREQ || string || nnn || The frequency channel <br />
|}<br />
<br />
<br />
The same structure applies to all ''SkyMap'' products, independent of whether they are full channel, survey of half-ring. The distinction between the types of maps is present in the FITS filename (and in the traceability comment fields).<br />
<br />
''' References'''<br />
<br />
<References /><br />
<br />
<br />
</div><br />
</div><br />
<br />
<br />
<br />
[[Category:Mission products|002]]</div>Azaccheihttps://wiki.cosmos.esa.int/planck-legacy-archive/index.php?title=Frequency_maps&diff=14110Frequency maps2018-07-06T13:42:27Z<p>Azacchei: /* File names */</p>
<hr />
<div>{{DISPLAYTITLE:Frequency maps in Temperature and Polarization}}<br />
==General description==<br />
<br />
Sky maps give the best estimate of the intensity and polarization (Stokes <i>Q</i> and <i>U</i> components), if available, of the signal from the sky after removal, as far as possible, of known systematic effects (mostly instrumental, but including also the solar and Earth-motion dipoles, Galactic stray light, and the zodiacal light). The Planck Collaboration has made three releases of maps, in 2013, 2015 and 2018. This section describes the 2018 release. For descriptions of the other two releases, please go to 2013, and 2015.<br />
<br />
In the 2013, 2015 and 2018 releases, sky maps are provided for the full Planck mission using all valid detectors in each frequency channel, and also for various subsets obtained by splitting the mission into various time ranges or into subsets of the detectors in a given channel, or by considering only odd or even pointing periods. These products are especially interesting for characterization purposes (see also the [[HFI-Validation | data validation]] section), though some are also useful for the study of source variability. The details of the start and end of the time ranges are given in the table below. <br />
<br />
For this (2018) release, HFI is providing a more limited subset of maps that include the full channel maps, the half-mission and the odd-even ring splits. Also, note that for the 353 GHz band, both full channel and PSBs only maps are provided, and that by default it is the PBS-only maps that are served.<br />
<br />
<br />
{| border="1" cellpadding="3" cellspacing="0" align="center" style="text-align:left" width=800px<br />
|+ '''Ranges for mission and surveys'''<br />
|- bgcolor="ffdead" <br />
! Range || ODs || HFI rings || pointing-IDs || Comment<br />
|-<br />
|Nominal mission || 91 - 563 || 240 - 14723 || 00004200 - 03180200 ||<br />
|-<br />
|Full mission || 91 - 974 || 240 - 27005 || 00004200 - 05322620 || For HFI<br />
|-<br />
|Full mission || 91 - 1543 || n/a || 00004200 - 06511160 || For LFI<br />
|-<br />
|Survey 1 || 91 - 270 || 240 - 5720 || 00004200 - 01059820 ||<br />
|-<br />
|Survey 2 || 270 - 456 || 5721 - 11194 || 01059830 - 02114520 ||<br />
|-<br />
|Survey 3 || 456 - 636 || 11195 - 16691 || 02114530 - 03193660 ||<br />
|-<br />
|Survey 4 || 636 - 807 || 16692 - 21720 || 03193670 - 04243900 ||<br />
|-<br />
|Survey 5 || 807 - 974 || 21721 - 26050 || 05267180 - 05322590 || End of mission for HFI<br />
|-<br />
|Survey 5 || 807 - 993 || n/a || 05267180 - 06344800 || End of survey for LFI<br />
|-<br />
|Survey 6 || 993 - 1177 || n/a || 06344810 - 06398120 || LFI only <br />
|-<br />
|Survey 7 || 1177 - 1358 || n/a || 06398130 - 06456410 || LFI only <br />
|-<br />
|Survey 8 || 1358 - 1543 || n/a || 06456420 - 06511160 || LFI only <br />
|-<br />
|HFI mission-half-1 || 91 - 531 || 240 - 13471 || 00004200 - 03155580 ||<br />
|-<br />
|HFI mission-half-2 || 531 - 974 || 13472 - 27005 || 03155590 - 05322590 ||<br />
|-<br />
|LFI Year 1 || 91 - 456 || n/a || 00004200 - 02114520 ||<br />
|-<br />
|LFI Year 2 || 456 - 807 || n/a || 02114530 - 04243900 ||<br />
|-<br />
|LFI Year 3 || 807 - 1177 || n/a || 05267180 - 06398120 ||<br />
|-<br />
|LFI Year 4 || 1177 - 1543 || n/a || 06398130 - 06511160 ||<br />
|-<br />
|}<br />
<br />
To help in further processing, there are also masks of the Galactic plane and of point sources, each provided for several different depths. <br />
<br />
All sky maps are in HEALPix format, with <i>N</i><sub>side</sub>=1024 (for LFI 30, 44, and 70GHz) and 2048 (for LFI 70GHz and HFI), in Galactic coordinates, and with nested ordering. <br />
<br />
'''WARNING''': The HEALPix convention for polarization is <b>not</b> the same as the IAU convention ([[#Polarization convention used in the Planck project|Section 8 on this page]]).<br />
<br />
The signal is given in units of K<sub>CMB</sub> for 30 to 353 GHz, and of MJy.sr<sup>-1</sup> (for a constant &nu;<i>I</i><sub>&nu;</sub> energy distribution) for 545 and 857 GHz. For each frequency channel, the intensity and polarization maps are packaged into a "BINTABLE" extension of a FITS file together with a hit-counts map (or "hits map", for short, giving the number of observation samples that are accumulated in a pixel, all detectors combined) and with the variance and covariance maps. Additional information is given in the FITS file header. The structure of the FITS file is given in the [[#FITS_file_structure | FITS file structure]] section below.<br />
<br />
==Production process==<br />
<br />
Sky maps are produced by appropriately combining the data from all working detectors in a frequency channel over some period of the mission. They give the best estimate of the signal from the sky (unpolarized) after removal, as far as possible, of known systematic effects and of the dipole signals induced by the motion of the solar system in the CMB and of the Planck satellite in the solar system. In particular, they include the zodiacal light emission ("zodi" for short) and also the scattering from the far sidelobes of the beams (FSL). More on this below.<br />
<br />
=== HFI processing ===<br />
<br />
The mapmaking and calibration process is described in detail in the [[Map-making_LFI | mapmaking]] section and in the {{PlanckPapers|planck2016-XLVI}} paper, where detailed references can be found. In brief, the timelines are cleaned and calibrated and converted into HealPix rings (HPRs), then ''SRoll'' is applied to destripe them in polarised space (removal of very low frequency noise by minimising differences at ring crossing points), to remove knows systematic effects (including the flux calibration), and to project them onto a HealPix map.<br />
<br />
The processing yields maps of the signal, hit counts and auto- and cross-variance maps for the 6 full channel and for a pseudo-channel built from the 353 PSBs only. For each channel HFI provides <br />
* a map for the full mission<br />
* two maps for each half-mission<br />
* two maps for built from odd or even rings only<br />
<br />
for a total of 35 maps. <br />
<br />
==== PR3 HFI products ====<br />
<br />
===== Healpix Pixel Rings (HPRs) =====<br />
''SRoll'' main products are the HFI frequency maps. Nevertheless, we also make available the Healpix Pixel Rings (HPRs) of those maps, ie. the data before projection. See [[Healpix_Rings_HFI| description of those files]].<br />
<br />
===== Frequency maps =====<br />
<br />
The 35 HFI frequency maps of the PR3 Legacy Release are the followings:<br />
<br />
{| border="1" cellpadding="3" cellspacing="0" align="center" style="text-align:left" width=800px<br />
|+ '''PR3 HFI frequency maps'''<br />
|- bgcolor="ffdead"<br />
!<br />
!100 GHz<br />
!143 GHz<br />
!217 GHz<br />
!353 GHz<br />
!353_PSB GHz<br />
!545 GHz<br />
!857 GHz<br />
|-<br />
| Full mission<br />
| I, Q, U<br />
| I, Q, U<br />
| I, Q, U<br />
| I, Q, U<br />
| I, Q, U<br />
| I<br />
| I<br />
|-<br />
| Half mission 1<br />
| I, Q, U<br />
| I, Q, U<br />
| I, Q, U<br />
| I, Q, U<br />
| I, Q, U<br />
| I<br />
| I<br />
|-<br />
| Half mission 2<br />
| I, Q, U<br />
| I, Q, U<br />
| I, Q, U<br />
| I, Q, U<br />
| I, Q, U<br />
| I<br />
| I<br />
|-<br />
| Odd rings<br />
| I, Q, U<br />
| I, Q, U<br />
| I, Q, U<br />
| I, Q, U<br />
| I, Q, U<br />
| I<br />
| I<br />
|-<br />
| Even rings<br />
| I, Q, U<br />
| I, Q, U<br />
| I, Q, U<br />
| I, Q, U<br />
| I, Q, U<br />
| I<br />
| I<br />
|}<br />
<br />
See [[Frequency_maps|description of those files]]. These maps are available on the [[https://www.cosmos.esa.int/web/planck/pla| Planck Legacy Archive]].<br />
<br />
<br />
=== LFI processing ===<br />
LFI maps were constructed with the MADAM mapmaking code, version 3.7.4. The code is based on a generalized destriping technique, where the correlated noise component is modelled as a sequence of constant offsets, called "baselines". A noise filter was used to constrain the baseline solution, allowing the use of 0.25-s and 1-s baselines for the 30 and 44GHz, and 70 GHz channels, respectively. See section 6 of {{PlanckPapers|planck2016-l02}}.<br />
<br />
<br />
Radiometers were combined according to the horn-uniform weighting scheme to minimize systematics. The flagged samples were excluded from the analysis by setting their weights to <i>C</i><sub>w</sub><sup>-1</sup> = 0. The Galaxy region was masked out in the destriping phase, to reduce errors arising from strong signal gradients. The polarization component was included in the analysis. <br />
<br />
; Dipole and Far Side Lobe correction: Input timelines are cleaned by the 4&pi;-convolved dipole and Galactic stray light, obtained as a convolution of the 4&pi; in-band far sidelobes and Galactic simulations, as explained in {{PlanckPapers|planck2016-l02}}. <br />
<br />
Scaling of the maps due to beam effects is taken into account in the LFI's beam functions (as provided in [[The_RIMO|the RIMO]]) which should be used for analysis of diffuse components.<br />
<br />
; Bandpass leakage correction :LFI high-resolution maps have been reseleased corrected for bandpass leakage or uncorrected. Further details about the procedure used to generate the bandpass correction maps can be found in section 7 of {{PlanckPapers|planck2016-l02}}.<br />
<br />
; Map zero-level : The 30, 44 and 70 GHz, maps are corrected for a zero-level monopole by applying an offset correction (see the LFI Calibration paper, {{PlanckPapers|planck2014-a06}}). Note that the offset applied is indicated in the header as a comment keyword.<br />
<br />
A detailed description of the mapmaking procedure is given in {{PlanckPapers|planck2013-p02}}, {{PlanckPapers|planck2014-a03}}, {{PlanckPapers|planck2014-a07}} and in the [[Map-making LFI#Map-making|Mapmaking]] section here, in {{PlanckPapers|planck2016-l02}} only a summary is reported.<br />
<br />
==Types of map ==<br />
<br />
=== Full-mission, full-channel maps (7 HFI, 4 LFI)===<br />
<br />
Full channel maps are built using all the valid detectors of a frequency channel and cover either the full or the nominal mission. For HFI, the 143-8 and 545-3 bolometers are rejected entirely, since they are seriously affected by RTS noise. HFI provides the Q and U components for the 100, 143, 217 and 353 GHz channels only. LFI provides the <i>I</i>, <i>Q</i>, and <i>U</i> maps for all the channels. Note that the HFI and LFI <i>Q</i> and <i>U</i> maps are corrected for bandpass leakage, version without correction for LFi is also provided. The <i>I</i>, <i>Q</i>, and <i>U</i> maps are displayed in the figures below. The colour range here is set using a histogram equalization scheme (from HEALPix) that is useful for these non-Gaussian data fields. For visualization purposes, the <i>Q</i> and <i>U</i> maps shown here have been smoothed with a 1&deg; Gaussian kernel, otherwise they look like noise to the naked eye. The 70 GHz full map is also available at <i>N</i><sub>side</sub>=2048.<br />
<br />
The high dynamic range colour scheme of the Planck maps is described [https://wiki.cosmos.esa.int/planck-legacy-archive/index.php/Planck_high_dynamic_range_colour_palette here].<br />
<br />
<center><br />
<gallery style="padding:0 0 0 0;" perrow=3 widths=260px heights=160px> <br />
File: LFI_030GHz_dx12_I.png| '''Full mission <i>I</i>, 30 GHz.'''<br />
File: LFI_044GHz_dx12_I.png| '''Full mission <i>I</i>, 44 GHz.'''<br />
File: LFI_070GHz_dx12_I.png| '''Full mission <i>I</i>, 70 GHz.'''<br />
File: SkyMap100e.png| '''Full mission <i>I</i>, 100 GHz.'''<br />
File: SkyMap143e.png| '''Full mission <i>I</i>, 143 GHz.'''<br />
File: SkyMap217e.png| '''Full mission <i>I</i>, 217 GHz.'''<br />
File: SkyMap353e.png| '''Full mission <i>I</i>, 353 GHz.'''<br />
File: SkyMap545e.png| '''Full mission <i>I</i>, 545 GHz.'''<br />
File: SkyMap857e.png| '''Full mission <i>I</i>, 857 GHz.'''<br />
</gallery><br />
</center><br />
<br><br />
<center><br />
<gallery style="padding:0 0 0 0;" perrow=3 widths=260px heights=160px> <br />
File: LFI_030GHz_dx12_Q.png| '''Full mission <i>Q</i>, 30 GHz.'''<br />
File: LFI_044GHz_dx12_Q.png | '''Full mission <i>Q</i>, 44 GHz.'''<br />
File: LFI_070GHz_dx12_Q.png | '''Full mission <i>Q</i>, 70 GHz.'''<br />
File: HFI_Skymap_100_full_bplcorrected_sm1deg_Qb.png | '''Full mission <i>Q</i>, 100 GHz.'''<br />
File: HFI_Skymap_143_full_bplcorrected_sm1deg_Qb.png | '''Full mission <i>Q</i>, 143 GHz.'''<br />
File: HFI_Skymap_217_full_bplcorrected_sm1deg_Qb.png | '''Full mission <i>Q</i>, 217 GHz.'''<br />
File: HFI_Skymap_353_full_bplcorrected_sm1deg_Qb.png | '''Full mission <i>Q</i>, 353 GHz.'''<br />
</gallery><br />
</center><br />
<br><br />
<center><br />
<gallery style="padding:0 0 0 0;" perrow=3 widths=260px heights=160px> <br />
File: LFI_030GHz_dx12_U.png| '''Full mission <i>U</i>, 30 GHz.'''<br />
File: LFI_044GHz_dx12_U.png | '''Full mission <i>U</i>, 44 GHz.'''<br />
File: LFI_070GHz_dx12_U.png | '''Full mission <i>U</i>, 70 GHz.'''<br />
File: HFI_Skymap_100_full_bplcorrected_sm1deg_Ub.png | '''Full mission <i>U</i>, 100 GHz.'''<br />
File: HFI_Skymap_143_full_bplcorrected_sm1deg_Ub.png | '''Full mission <i>U</i>, 143 GHz.'''<br />
File: HFI_Skymap_217_full_bplcorrected_sm1deg_Ub.png | '''Full mission <i>U</i>, 217 GHz.'''<br />
File: HFI_Skymap_353_full_bplcorrected_sm1deg_Ub.png | '''Full mission <i>U</i>, 353 GHz.'''<br />
</gallery><br />
<br />
</center><br />
<br />
=== Full mission light maps, full channel maps (7 HFI, 7 LFI)===<br />
<br />
These maps are based on the Full mission maps but contain fewer columns, IQU from 30 to 353 GHz, and I only at 545 and 857 GHz. These maps have been produced to reduce the transfer time of the most downloaded frequency full mission maps.<br />
<br />
=== Single-survey, full-channel maps (35 LFI)===<br />
<br />
Single-survey maps are built using all valid detectors of a frequency channel; they separately cover the different sky surveys. The surveys are defined as the times over which the satellite spin axis rotates by 180&deg;, which, due to the position of the detectors in the focal plane does not cover the full sky, but a fraction between about 80% and 90%, depending on detector position. During adjacent surveys the sky is scanned in opposite directions (more precisely it is the ecliptic equator that is scanned in opposite directions). While these are useful to investigate variable sources, they are also used to study the systematics of the time-response of the detectors as they scan bright sources, like the Galactic Plane, in different directions during different survey. Note that the HFI and LFI missions cover five and eight surveys, respectively, and in the case of HFI the last survey in incomplete.<br />
The 70 GHz survey maps are available also at <i>N</i><sub>side</sub>=2048. Note that LFI provides a special survey-map combination used in the low-&#8467; analysis; this maps, available at the three LFI frequencies, 30, 44, and 70 GHz, was built using the combination of Surveys 1, 3, 5, 6, 7, and 8.<br />
<br />
=== Year maps, full-channel maps (16 LFI)===<br />
<br />
These maps are built using the data of Surveys 1+2, Surveys 3+4, and so forth. They are used to study long-term systematic effects. The 70 GHz years maps are available also at <i>N</i><sub>side</sub>=2048.<br />
<br />
===Half-mission maps, full-channel maps (14 HFI, 12 LFI)===<br />
<br />
For HFI, the half mission is defined after eliminating those rings that are discarded for all bolometers, many of which occurred during the 5th survey when the "End-of-Life" tests were performed. The remaining rings are divided in half to define the two halves of the mission. This exercise is done for the full mission only.<br />
<br />
For LFI, instead of the half-mission maps, the following year combinations have been created: Year 1+2, Year 1+3, Year 2+4, Year 3+4,<br />
<br />
===Full mission, single-detector maps (22 LFI)===<br />
<br />
For LFI, all the 22 Radiometers maps are available, and (obviously) only in Stokes <i>I</i>.<br />
<br />
===Full-mission, detector-set or detector-pairs maps (8 LFI)===<br />
<br />
The objective here is to build independent temperature (<i>I</i>) and polarization (<i>Q</i> and <i>U</i>) maps using the two pairs of polarization-sensitive detectors of each channel where they are available, i.e., for the 44-353 GHz channels. The table below indicates which detectors were used to build each detector set (detset).<br />
<br />
{| border="1" cellpadding="3" cellspacing="0" align="center" style="text-align:left" width=600px<br />
|+ '''Definition of LFI detector pairs'''<br />
|- bgcolor="ffdead" <br />
!Frequency || Horn pair || Comment <br />
|-<br />
|44 GHz || 24 || This map is only in temperature<br />
|-<br />
|44 GHz || 25 and 26 || <br />
|-<br />
|70 GHz || 18 and 23 || Available also at <i>N</i><sub>side</sub>=2048<br />
|-<br />
|70 GHz || 19 and 22 || Available also at <i>N</i><sub>side</sub>=2048<br />
|-<br />
|70 GHz || 20 and 21 || Available also at <i>N</i><sub>side</sub>=2048<br />
|}<br />
<br />
===Half-ring maps (62 LFI)===<br />
<br />
These maps are similar to the ones described above, but are built using only the first or the second halves of each ring (or pointing period). The HFI provides half-ring maps for the full mission only, as well as for the full channel, the detsets, and the single bolometers. The LFI provides half-ring maps for the full mission in each channel (70 GHz also at <i>N</i><sub>side</sub>=2048), for the full-mission radiometers, and for the full-mission horn pairs.<br />
<br />
=== Odd and even rings maps (14 HFI)<br />
<br />
As the name indicates, these are generated by using only the odd or only the even rings.<br />
<br />
=== Caveats and known issues ===<br />
<br />
'''TBC'''<br />
<br />
==== Caveats when using the HFI frequency maps ====<br />
Some imperfections have shown up in the tests of the HFI PR3 maps that were previously hidden by higher-level systematics in the previous PR2 data. These lead to guidelines for the proper use of the HFI PR3 data.<br />
<br />
===== Monopoles =====<br />
Monopoles, which cannot be extracted from Planck data alone, are adjusted at each frequency (as was done in the previous PR2 release). For component separation, this provides maps that can be used directly in combination with other tracers.<br />
This monopole includes a CIB model, a diffuse ISM signal adjusted on the HI tracer, and a zodiacal emission signal adjusted to the proper absolute intensity.<br />
<br />
=====Use of the 353 GHz SWBs ===== <br />
We deliver two data sets: the recommended one not using the 353 GHz SWBs data, and the other one including the 353 GHz SWBs for specific use like, for example, increasing the signal to noise level at high multipoles.<br />
<br />
===== Color correction and component separation=====<br />
Different responses between bolometers to different foregrounds cannot be used with the PR3 release to extract component maps. Single bolometer maps computed by Sroll in a frequency band, are all adjusted by construction to the band average response.<br />
<br />
===== Sub-pixel effect in very bright regions===== <br />
The bandpass corrections have been optimized for high latitude regions which implied to reduce the noise of the CO and dust bandpass templates to avoid the introduction of significant correlated noise. The effect is negligible for dust but not for CO in very bright regions. See [[subpixel_HFI|detailled description]].<br />
<br />
===== Solar dipole residual===== <br />
The ''Planck'' 2015 Solar dipole is removed from the PR3 HFI maps to be consistent with LFI maps and to facilitate comparison with the previous PR2 ones. The best Solar dipole determination from HFI PR3 data shows a small shift in direction of about 1', but a 1.8 &mu;K lower amplitude. Removal of the ''Planck'' 2015 Solar dipole thus leaves a small but non-negligible dipole residual in the HFI PR3 maps. To correct for this, and adjust maps at the best photometric calibration, users of the HFI PR3 maps should:<br />
# put back into the maps the ''Planck'' 2015 Solar dipole (d,l,b)= (3364.5 &plusmn; 2.0 &mu;K, 264.00 &plusmn; 0.03&deg;, 48.24 &plusmn; 0.02&deg;),<br />
# include the [[#Calibration accuracy|absolute calibration frequency bias]], i.e., multiply by 1 minus the calibration bias,<br />
# lastly, remove the [[#HFI 2018 Solar dipole|HFI 2018 Solar dipole]].<br />
<br />
==Inputs==<br />
=== HFI inputs ===<br />
<br />
The HFI mapmaking takes as input:<br />
* the cleaned TOIs of the signal from each detector, together with their flags, produced by the [[TOI processing|TOI processing]] pipeline;<br />
* the TOIs of pointing (quaternions), described in [[Detector_pointing|Detector pointing]];<br />
* bolometer-level characterization data, from the DPC's internal IMO (not distributed);<br />
* Planck orbit data, used to compute and remove the Earth's dipole;<br />
* Planck solar dipole information, used to calibrate the CMB channels;<br />
* planet models used to calibrate the Galactic channels.<br />
<br />
=== LFI inputs ===<br />
<br />
The MADAM mapmaker takes as input:<br />
* the calibrated timelines (for details see [[TOI processing LFI|TOI Processing]]);<br />
* the detector pointings (for details see [[Detector_pointing|Detector pointing]]);<br />
* the noise information in the form of 3-parameter (white noise level &sigma;, slope, and knee frequency <i>f</i><sub>knee</sub>) noise model (for details see [[The RIMO|RIMO]]).<br />
<br />
==Related products==<br />
=== Masks ===<br />
This section presents the "general purpose" masks. Other masks specific to certain products are packaged with those products.<br />
<br />
Note that for this release, HFI has not produced any new masks. <br />
<br />
==== Gatactic Centre masks ====<br />
<br />
'''TBW'''<br />
<br />
<br />
====Point source masks [TO BE REMOVED ??]====<br />
<br />
For HFI and LFI two sets of point-source masks are provided. <br />
* Intensity masks, which remove sources detected with S/N > 5. <br />
* Polarisation masks, which remove sources that have polarization detection significance levels of 99.97 % or greater at the position of a source detected in intensity. They were derived from the polarization maps with dust foreground bandpass mismatch leakage corrections applied. The area excised around each source has a radius of 3σ (width) of the beam, i.e., 1.27 FWHM (for LFI the cut around each source has a radius of 32 arcmin at 30GHz, 27 arcmin at 44 GHz, and 13 arcmin at 70 GHz).<br />
<br />
Both sets of masks are found in the files ''HFI_Mask_PointSrc_2048_R2.00.fits'' and ''LFI_Mask_PointSrc_2048_R2.00.fits'', in which the first extension contains the intensity masks, and the second contains the polarization masks.<br />
<br />
====Galactic plane masks [TO BE REMOVED ??]====<br />
<br />
Eight Galactic emission masks are provided, giving 20, 40, 60, 70, 80, 90, 97, and 99% sky coverage, derived from the 353 GHz map after CMB subtraction. These are independent of frequency channel. Three versions are given: not apodized; and apodized by 2&deg; and 5&deg;. The filenames are ''HFI_Mask_GalPlane-apoN_2048_R2.00.fits'', where <i>N</i> = 0, 2, and 5.<br />
<br />
The masks are shown below. The eight "GalPlane" masks are combined (added together) and shown in a single figure for each of the three apodizations. While the result is quite clear for the case of no apodization, it is less so for the apodized case. The "PointSrc" masks are shown separately for the intensity case.<br />
<br />
<center><br />
<gallery perrow=3 widths=260px heights=160px ><br />
File: GalPlaneMask_apo0.png | '''Galactic plane masks, no apodization.'''<br />
File: GalPlaneMask_apo2.png | '''Galactic plane masks, apodized to 2&deg;.'''<br />
File: GalPlaneMask_apo5.png | '''Galactic plane masks, apodized to 5&deg;.'''<br />
File: PointSrcMask_100.png | '''Point source mask, 100 GHz.'''<br />
File: PointSrcMask_143.png | '''Point source mask, 143 GHz.'''<br />
File: PointSrcMask_217.png | '''Point source mask, 217 GHz.'''<br />
File: PointSrcMask_353.png | '''Point source mask, 343 GHz.'''<br />
File: PointSrcMask_545.png | '''Point source mask, 545 GHz.'''<br />
File: PointSrcMask_857.png | '''Point source mask, 857 GHz.'''<br />
</gallery><br />
</center><br />
<br />
== File names ==<br />
The FITS filenames are of the form ''{H|L}FI_SkyMap_fff{-tag}_Nside_R3.nn_{coverage}-{type}.fits'', where "fff" are three digits to indicate the Planck frequency band, "tag" indicates the single detector or the detset (no "tag" indicates full channel), "Nside" is the HEALPix <i>N</i><sub>side</sub> value of the map, "coverage" indicates which part of the mission is covered (full, half mission, survey, year, etc.), and the optional "type" indicates the subset of input data used. The table below lists the products by type, with the appropriate unix wildcards that form the full filename.<br />
<br />
{| class="wikitable" align="center" style="text-align"left" border="1" cellpadding="15" cellspacing="20" width=880px<br />
|+ '''HFI FITS filenames'''<br />
|- bgcolor="ffdead"<br />
! Coverage || Filename <br />
|-<br />
| Full channel, full mission ||HFI_SkyMap_fff{-tag}_2048_R3.??_full.fits<br />
|-<br />
| Full channel, half mission || HFI_SkyMap_fff{-tag}_2048_R3.??_halfmission-{1/2}.fits<br />
|-<br />
| Full channel, full mission, odd/even ring || HFI_SkyMap_fff{-tag}_2048_R3.??_{odd/even}ring.fits <br />
|}<br />
<br />
{| class="wikitable" align="center" style="text-align"left" border="1" cellpadding="15" cellspacing="20" width=1000px<br />
|+ '''LFI FITS filenames'''<br />
|- bgcolor="ffdead"<br />
! Coverage || Filename || Half-ring filename || Comment<br />
|-<br />
| Full channel, full mission ||LFI_SkyMap_???_1024_R3.??_full.fits ||LFI_SkyMap_???_1024_R2.??_full-ringhalf-?.fits || Available also at Nside = 2048<br />
|-<br />
| Full channel, full mission ||LFI_SkyMap_???-BPassCorrected_1024_R3.??_full.fits ||LFI_SkyMap_???-BPassCorrected_???_1024_R2.??_full-ringhalf-?.fits || Available also at Nside = 2048<br />
|-<br />
| Full channel, single survey || LFI_SkyMap_???_1024_R3.??_survey-?.fits || n/a || Available also at <i>N</i><sub>side</sub>=2048<br />
|-<br />
| Full channel, survey combination || LFI_SkyMap_???_1024_R3.??_survey-1-3-5-6-7-8.fits || n/a || n/a<br />
|-<br />
| Full channel, survey combination || LFI_SkyMap_???_1024_R3.??_survey-1-3-5-6-7-8.fits || n/a || n/a<br />
|-<br />
| Full channel, single year || LFI_SkyMap_???-BPassCorrected_1024_R3.??_year-?.fits || n/a || Available also at <i>N</i><sub>side</sub>=2048<br />
|-<br />
| Full channel, single year || LFI_SkyMap_???-BPassCorrected_1024_R3.??_year-?.fits || n/a || Available also at <i>N</i><sub>side</sub>=2048<br />
|-<br />
| Full channel, year combination || LFI_SkyMap_???_1024_R3.??_year?-?.fits || n/a || n/a<br />
|-<br />
| Full channel, year combination || LFI_SkyMap_???-BPassCorrected_1024_R3.??_year?-?.fits || n/a || n/a<br />
|-<br />
| Horn pair, full mission || LFI_SkyMap_???-??-??_1024_R3.??_full.fits || LFI_SkyMap_???_??-??_1024_R3.??_full-ringhalf-?.fits || Available also at <i>N</i><sub>side</sub>2048<br />
|-<br />
| Single radiometer, full mission || LFI_SkyMap_???-???_1024_R3.??_full.fits || LFI_SkyMap_???-???_1024_R3.??_full-ringhalf-?.fits || n/a<br />
|}<br />
<br />
For the benefit of users who are only looking for the frequency maps with no additional information, we also provide a file combining the nine frequency maps as separate columns in a single extension. The nine columns in this file contain the intensity maps <i>only</i> and no other information (hits maps or variance maps) is provided.<br />
<br />
== FITS file structure ==<br />
<br />
The FITS files for the sky maps contain a minimal primary header with no data, and a ''BINTABLE'' extension (EXTENSION 1, EXTNAME = ''FREQ-MAP'') containing the data. The structure is shown schematically in the figure below. The ''FREQ-MAP'' extension contains a 3- or 10-column table that contain the signal, hit-count, and variance maps, all in HEALPix format. The 3-column case is for intensity only maps, while the 10-column case is for polarization. The number of rows is the number of map pixels, which is <i>N</i><sub>pix</sub> = 12 <i>N</i><sub>side</sub><sup>2</sup> for HEALPix maps, where <i>N</i><sub>side</sub> = 1024 or 2048 for most the maps presented in this section.<br />
<br />
[[File:FITS_FreqMap.png | 550px | center | thumb | '''FITS file structure.''']]<br />
<br />
Note that file sizes are approximately 0.6 GB for <i>I</i>-only maps and 1.9 GB for <i>IQU</i> maps at <i>N</i><sub>side</sub>=2048, but about 0.14 GB for <i>I</i>-only maps and 0.45 GB for <i>IQU</i> maps at <i>N</i><sub>pix</sub>=1024 .<br />
<br />
Keywords indicate the coordinate system ("GALACTIC"), the HEALPix ordering scheme ("NESTED"), the units (K<sub>CMB</sub> or MJy.sr<sup>-1</sup>) of each column, and of course the frequency channel ("FREQ"). Where polarization <i>Q</i> and <i>U</i> maps are provided, the "COSMO" polarization convention (used in HEALPix) is adopted, and it is specified in the "POLCCONV" keyword (see [[Sky_temperature_maps#Polarization_convention_used_in_the_Planck_project|this section]]). The "COMMENT" fields give a one-line summary of the product, and some other information useful for traceability within the DPCs. The original filename is also given in the "FILENAME" keyword. The "BAD_DATA" keyword gives the value used by HEALPix to indicate pixels for which no signal is present (these will also have a hit-count value of 0). The main parameters are summarized in the table below.<br />
<br />
{| border="1" cellpadding="3" cellspacing="0" align="center" style="text-align:left" width=800px<br />
|+ '''Sky map file data structure'''<br />
|- bgcolor="ffdead" <br />
!colspan="4" | 1. EXTNAME = 'FREQ-MAP' : Data columns<br />
|- bgcolor="ffdead" <br />
! Column name || Data type || Units || Description<br />
|-<br />
|I_STOKES || Real*4 || K<sub>CMB</sub> or MJy.sr<sup>-1</sup> || Stokes <i>I</i> map<br />
|-<br />
|Q_STOKES || Real*4 || K<sub>CMB</sub> or MJy.sr<sup>-1</sup> || Stokes <i>Q</i> map (optional)<br />
|-<br />
|U_STOKES || Real*4 || K<sub>CMB</sub> or MJy.sr<sup>-1</sup> || Stokes <i>U</i> map (optional)<br />
|-<br />
|HITS || Int*4 || none || The hit-count map<br />
|-<br />
|II_COV || Real*4 || K<sub>CMB</sub><sup>2</sup> or (MJy.sr<sup>-1</sup>)<sup>2</sup> || <i>II</i> variance map<br />
|-<br />
|IQ_COV || Real*4 || K<sub>CMB</sub><sup>2</sup> or (MJy.sr<sup>-1</sup>)<sup>2</sup> || <i>IQ</i> variance map (optional)<br />
|-<br />
|IU_COV || Real*4 || K<sub>CMB</sub><sup>2</sup> or (MJy.sr<sup>-1</sup>)<sup>2</sup> || <i>IQ</i> variance map (optional)<br />
|-<br />
|QQ_COV || Real*4 || K<sub>CMB</sub><sup>2</sup> or (MJy.sr<sup>-1</sup>)<sup>2</sup> || <i>QQ</i> variance map (optional)<br />
|-<br />
|QU_COV || Real*4 || K<sub>CMB</sub><sup>2</sup> or (MJy.sr<sup>-1</sup>)<sup>2</sup> || <i>QU</i> variance map (optional)<br />
|-<br />
|UU_COV || Real*4 || K<sub>CMB</sub><sup>2</sup> or (MJy.sr<sup>-1</sup>)<sup>2</sup> || <i>UU</i> variance map (optional)<br />
|-<br />
|- bgcolor="ffdead" <br />
! Keyword || Data type || Value || Description<br />
|-<br />
|PIXTYPE || String || HEALPIX ||<br />
|-<br />
|COORDSYS || String || GALACTIC ||Coordinate system <br />
|-<br />
|ORDERING || String || NESTED || Healpix ordering<br />
|-<br />
|POLCCONV || String || COSMO || Polarization convention<br />
|-<br />
|NSIDE || Int || 1024 or 2048 || HEALPix <i>N</i><sub>side</sub> <br />
|-<br />
|FIRSTPIX || Int*4 || 0 || First pixel number<br />
|-<br />
|LASTPIX || Int*4 || 12 <i>N</i><sub>side</sub><sup>2</sup> – 1 || Last pixel number<br />
|-<br />
|FREQ || String || nnn || Frequency channel <br />
|}<br />
<br />
<br />
The same structure applies to all "SkyMap" products, independent of whether they are full channel, survey of half-ring. The distinction between the types of maps is present in the FITS filename (and in the traceability comment fields).<br />
<br />
==Polarization convention used in the Planck project==<br />
<br />
The FITS keyword "POLCCONV" defines the polarization convention of the data within the file.<br />
The Planck collaboration used the COSMO convention for the polarization angle (as usually adopted in space-based and other CMB missions), whereas other subfields of astronomy usually adopt the IAU convention. The basic difference comes down to whether one thinks of the light rays being emitted from the origin (the usual mathematics/physics convention) or converging on the observer from the sky (the usual astronomy convention), and hence the "obvious" choice is different for a physicists and for an astronomer. Given that CMB results are of interest to a wide range of both physicists and astronomers, there is no single choice of convention that everyone would regard as self-evident. Hence one simply has to be aware of the convention being adopted. Because of this the Planck Collaboration has taken pains to point out which convention is being used in publications and in data releases. In the following we describe the difference between these two conventions, and the consequence if it is <i>not</i> taken into account correctly in the analysis.<br />
<br />
[[File:conventions.png|thumb|center|400px|'''Figure 1. Polarization conventions, showing the COSMO convention (left) and IAU convention (right). The vector <math>\hat{z}</math> points in the outward direction in COSMO, and inwards in IAU. The bottom panel refers to the plane tangent to the sphere.''']]<br />
<br />
Changing the orientation convention is equivalent to a transformation &psi;'=&pi;-&psi; of the polarization angle (Figure 1). The consequence of this transformation is the inversion of the Stokes parameter <i>U</i>.<br />
The components of the polarization tensor in the helicity basis <math>\epsilon^{\pm}=(\hat{x}\pm i\hat{y})/\sqrt{2}</math> are<br />
<br />
<math><br />
(Q+iU)(\hat{n}) = \sum _{\ell m}a_{2,lm}{}_{2}Y_{\ell }^{m}(\hat{n}),<br />
\\(Q-iU)(\hat{n}) = \sum _{\ell m}a_{-2,lm}{}_{2}Y_{\ell }^{m}(\hat{n}),<br />
</math><br />
<br />
where <math>{}_{2}Y_{\ell }^{m}(\hat{n})</math> are the spin-weighted spherical harmonic functions.<br />
The <i>E</i> and <i>B</i> modes can be defined as<br />
<br />
<math><br />
E(\hat{n}) = \sum_{\ell m}a_{E,\ell m}Y_{\ell }^{m}(\hat{n}),<br />
\\B(\hat{n}) = \sum_{\ell m}a_{B,\ell m}Y_{\ell }^{m}(\hat{n}),<br />
</math><br />
<br />
where the coefficients <i>a<sub>E,&#8467;m</sub></i> and <i>a<sub>B,&#8467;m</sub></i> are derived from linear combinations of the <i>a<sub>2,&#8467;m</sub></i>, <i>a<sub>-2,&#8467;m</sub></i>, defined implicitly in the first equation (<i>Q</i>&plusmn; i<i>U</i>).<br />
<br />
[[File:test_gradient.jpg|thumb|center|400px|]]<br />
[[File:test_curl.jpg|thumb|center|400px|'''Figure 2. Error on Planck-LFI 70 GHz <i>EE</i> (top) and <i>BB</i> (bottom) power spectra, in the case of an incorrect choice being made for the polarization coordinate system convention (IAU instead of COSMO).''']]<br />
<br />
The effect of the sign inversion of <i>U</i> on the polarization spectra is a non-trivial mixing of <i>E</i> and <i>B</i> modes. <br />
An example of the typical error on <i>EE</i> and <i>BB</i> auto-spectra in the case of the wrong choice for the polarization basis is shown in Figure 2.<br />
<br />
<i>One should be careful</i> to be aware of the polarization convention that is being adopted. If the IAU convention is used in computing the power spectra, then the sign of the <i>U</i> component of the Planck maps must be inverted before computing the <i>E</i> and <i>B</i> modes.<br />
<br />
In astronomical applications it is common to define a pseudo-vector <i>P</i> to show the amplitude and orientation of<br />
polarization on a map. When plotting these line segments to show the orientation of the plane of polarization (or the orthogonal direction, often considered to be the projection of the magnetic field), the results are the same for both the COSMO and IAU conventions. This because the appearance of <i>P</i> is a property of the radiation and hence not affected by the sign of <i>U</i>.<br />
<br />
=== Note on the convention used in the Planck Catalogue of Compact Sources (PCCS) ===<br />
Planck non-cosmology papers sometimes follow the IAU convention for internal analysis, for ease of comparison with other studies (e.g., comparison of Planck-derived thermal dust emission polarization with the optical polarization of starlight). Nevertheless, Planck data products, such as component-separated maps, still use the COSMO convention. The one exception is for the compact source catalogue. Because catalogues of astronomical objects found by Planck need to be compared directly with other source catalogues, the polarized sources described in the Planck Catalogue of Compact Sources follow the IAU convention, and the polarization angles are defined on an interval of [-90&deg;,90&deg;]. To switch to the COSMO convention, the polarization angles listed in the catalogue should be shifted by 90&deg; and multiplied by -1.<br />
<br />
== References ==<br />
<References /><br />
<br />
<br />
<span style="background:green"><br />
<br />
<span style="background:green"><br />
== Previous releases ==<br />
<br />
<div class="toccolours mw-collapsible mw-collapsed" style="background-color: #FFDAB9;width:80%" ><br />
'''2015 Sky temperature and polarization maps'''<br />
<br />
<div class="mw-collapsible-content"><br />
<br />
<br />
'''General description'''<br />
<br />
Sky maps give the best estimate of the intensity and polarization (Stokes Q and U components), if available, of the signal from the sky after removal, as far as possible, of known systematic effects (mostly instrumental, but including also the solar and earth-motion dipole, Galactic strylight and the Zodiacal light). Sky maps are provided for the full Planck mission using all valid detectors in each frequency channel, and also for various subsets by splitting the mission in various time ranges or in subsets of the detectors in a given channel. These products are useful for the study of source variability, but they are especially interesting for characterisation purposes (see also the [[HFI-Validation | data validation]] section). The details of the start and end of the time ranges are given in the table below.<br />
<br />
To help in further processing, there are also masks of the Galactic Plane and of point sources, each provided for several different depths.<br />
<br />
All sky maps are in Healpix format, with Nside of 1024 (LFI 30, 44 and 70) and 2048 (LFI 70 and HFI), in Galactic coordinates, and Nested ordering. <br />
<br />
;WARNING: the Healpix convention for polarization is NOT the same as the IAU convention - see Section 8 in this page.<br />
<br />
The signal is given in units of K<sub>cmb</sub> for 30-353 GHz, and of MJy/sr (for a constant <math>\nu F_\nu</math> energy distribution ) for 545 and 857 GHz. For each frequency channel, the intensity and polarization maps are packaged into a ''BINTABLE'' extension of a FITS file together with a hit-count map (or hit map, for short, giving the number of observation samples that are cumulated in a pixel, all detectors combined) and with the variance and covariance maps. Additional information is given in the FITS file header. The structure of the FITS file is given in the [[#FITS_file_structure | FITS file structure]] section below. <br />
<br />
; R2.00 : this first release (Jan 2015) contains polarisation data for the 353 GHz channel only.<br />
; R2.01 : this second release (May 2015) adds polarisation data to the 100-217 GHz channels.<br />
; R2.02 : a full re-release to correct the Healpix bad pixel value in the maps which was altered during the preparation of the maps and not reset to the correct value (the valid pixels are unchanged). It also fixes some FITS keywords, and includes a full re-release of the Zodi correction maps, with the 100-217 GHz one now including the polarisation correction)<br />
<br />
{| border="1" cellpadding="3" cellspacing="0" align="center" style="text-align:left" width=800px<br />
|+ '''Ranges for mission and surveys'''<br />
|- bgcolor="ffdead" <br />
! Range || ODs || HFI rings || pointing-IDs || Comment<br />
|-<br />
|nominal mission || 91 - 563 || 240 - 14723 || 00004200 - 03180200 ||<br />
|-<br />
|full mission || 91 - 974 || 240 - 27005 || 00004200 - 05322620 || for HFI<br />
|-<br />
|full mission || 91 - 1543 || n/a || 00004200 - 06511160 || for LFI<br />
|-<br />
|Survey 1 || 91 - 270 || 240 - 5720 || 00004200 - 01059820 ||<br />
|-<br />
|Survey 2 || 270 - 456 || 5721 - 11194 || 01059830 - 02114520 ||<br />
|-<br />
|Survey 3 || 456 - 636 || 11195 - 16691 || 02114530 - 03193660 ||<br />
|-<br />
|Survey 4 || 636 - 807 || 16692 - 21720 || 03193670 - 04243900 ||<br />
|-<br />
|Survey 5 || 807 - 974 || 21721 - 27005 || 05267180 - 05322590 || end of mission for HFI<br />
|-<br />
|Survey 5 || 807 - 993 || n/a || 05267180 - 06344800 || end of survey for LFI<br />
|-<br />
|Survey 6 || 993 - 1177 || n/a || 06344810 - 06398120 || LFI only <br />
|-<br />
|Survey 7 || 1177 - 1358 || n/a || 06398130 - 06456410 || LFI only <br />
|-<br />
|Survey 8 || 1358 - 1543 || n/a || 06456420 - 06511160 || LFI only <br />
|-<br />
|Survey 9 || 1543 - 1604 || n/a || 06511170 - 06533320 || LFI only Not in this delivery<br />
|-<br />
|HFI mission-half-1 || 91 - 531 || 240 - 13471 || 00004200 - 03155580 ||<br />
|-<br />
|HFI mission-half-2 || 531 - 974 || 13472 - 27005 || 03155590 - 05322590 ||<br />
|-<br />
|LFI Year 1 || 91 - 456 || n/a || 00004200 - 02114520 ||<br />
|-<br />
|LFI Year 2 || 456 - 807 || n/a || 02114530 - 04243900 ||<br />
|-<br />
|LFI Year 3 || 807 - 1177 || n/a || 05267180 - 06398120 ||<br />
|-<br />
|LFI Year 4 || 1177 - 1543 || n/a || 06398130 - 06511160 ||<br />
|-<br />
|}<br />
<br />
'''Production process'''<br />
<br />
Sky maps are produced by combining appropriately the data of all working detectors in a frequency channel over some period of the mission. They give the best estimate of the signal from the sky (unpolarised) after removal, as far as possible, of known systematic effects and of the dipole signals induced by the motion of the solar system in the CMB and of the Planck satellite in the solar system. In particular, they include the Zodiacal light emission (Zodi for short) and also the scattering from the far-side lobes of the beams (FSL). More on this below.<br />
<br />
''' HFI processing '''<br />
<br />
The mapmaking and calibration process is described in detail in the [[Map-making_LFI | Map-making]] section and in the {{PlanckPapers|planck2014-a09}} paper, where detailed references are found. In brief it consists of:<br />
<br />
; binning the TOI data onto ''rings'' : Healpix rings (HPRs) are used here, each ring containing the combined data of one pointing period. <br />
; flux calibration : at 100-353 GHz, the flux calibration factors are determined by correlating the signal with the orbital dipole, which is determined very accurately from the Planck satellite orbital parameters provided by Flight Dynamics. This provides a single gain factor per bolometer. At 545 and 857 GHz the gain is determined from the observation of Uranus and Neptune (but not Jupiter which is too bright) and comparison to recent models made explicitly for this mission. A single gain is applied to all rings at these frequencies.<br />
; destriping : in order to remove low-frequency noise, an offset per ring is determined by minimizing the differences between HPRs at their crossings, and removed.<br />
; Zodiacal light correction : a Zodiacal light model is used to build HPRs of the the Zodi emission, which is subtracted from the calibrated HPRs.<br />
; projection onto the map : the offset-corrected, flux-calibrated, and Zodi-cleaned HPRs are projected onto Healpix maps, with the data of each bolometer weighted by a factor of 1/NET of that bolometer.<br />
<br />
These steps are followed by some post-processing which is designed to prepare the maps for the component separation work. This post processing consists of: <br />
<br />
; Dust bandpass leakage correction : the Q and U maps are corrected for the intensity-to-polarisation leakage caused by the foregrounds having a non-CMB spectrum, and as a consequence of the non-identical bandpasses on the different detectors (bandpass mismatch, or BPM). This correction is determined using the ''ground'' method as described in Section 7.3 of {{PlanckPapers|planck2014-a09}}. These correction maps can be found in the Planck Legacy Archive as ''HFI_CorrMap_???-dustleak-ground_2048_R2.0?_{coverage}.fits''. The correction is applied by subtracting the correction map from the corresponding input map. This correction is not applied to the nominal mission maps in order to maintain compatibility with the PR1 products. ''In fact this correction was computed and applied only to the products used in component separation'', so they were not applied to the single survey maps and to the half-ring maps, which are considered characterisation products.<br />
; Far Side Lobe calibration correction : the 100-217 maps are multiplied by factors of 1.00087, 1.00046, and 1.00043, respectively, to compensate for the non-removal of the far-side lobes, and similarly the corresponding covariance maps have also been corrected by multiplication by the square of the factor.<br />
; Fill missing pixels : missing pixels are filled in with a value that is the mean of valid pixels within a given radius. A radius of 1 deg is used for the full channel maps, and 1.5 deg is used for the detset maps. This step is not applied to the single survey maps since they have large swaths of the sky that are not covered.<br />
<br />
; Map zero-level : for the 100 to 857 GHz maps, the zero levels are set to their optimal levels for Galactic and CIB studies. A procedure for adjusting them to astrophysical values is given in the HFI Mapmaking and Calibration paper {{PlanckPapers|planck2014-a09}}.<br />
<br />
These maps provide the main mission products. Together with signal maps, hit count, variance, and variance maps are also produced. The hit maps give the (integer) number of valid TOI-level samples that contribute to the signal of each pixel. All valid samples are counted in the same way, i.e., there is no weighting factor applied. The variance maps project the white noise estimate, provided by the NETs, in the sky domain.<br />
<br />
Note that the nominal mission maps have not had the post-processing applied, which makes them more easily comparable to the PR1 products.<br />
<br />
''' LFI processing '''<br />
LFI maps were constructed with the Madam map-making code, version 3.7.4. The code is based on generalized destriping technique, where the correlated noise component is modeled as a sequence of constant offset, called baselines. A noise filter was used to constrain the baseline solution allowing the use of 0.25 s and 1 second baselines for the 30 and 44, 70 GHz respectively.<br />
<br />
Radiometers were combined according to the horn-uniform weighting scheme to minimize systematics. The used weights are listed in [[Map-making LFI#Map-making|Map-making]]. The flagged samples were excluded from the analysis by setting their weights to <math>C_{w}^{-1}</math> = 0. The galaxy region was masked out in the destriping phase, to reduce error arising from strong signal gradients. The polarization component was included in the analysis... <br />
<br />
; Dipole and Far Side Lobe correction : input timelines are cleaned by 4pi convolved dipole and Galactic Straylight obtained as convolution of the 4pi in band far sidelobes and Galactic Simulation as explained in Section 7.4 of {{PlanckPapers|planck2014-a03}}. <br />
<br />
Beam effects on the LFI maps are described in Section 7.1 of {{PlanckPapers|planck2014-a03}}. Scaling of the maps due to beam effects is taken into account in the LFI's beam functions (as provided in the RIMO, give reference) which should be used for analysis of diffuse components. To compute the flux densities of compact sources, correction must be made for beam effects (see Table 8 of {{PlanckPapers|planck2014-a03}})."<br />
<br />
; Bandpass leakage correction : '''as opposed to the HFI, the LFI high resolution maps have not been corrected for bandpass leakage. Only low resolution (nside 256) maps are provided with the bandpass correction'''. The correction maps (LFI_CorrMap_0??-BPassCorr_*.fits) can be found in the Planck Legacy Archive. Further details about the procedure used to generate the bandpass correction maps can be found in Section 11 of {{PlanckPapers|planck2014-a03}}.<br />
<br />
; Map zero-level : for the 30, 44 and 70 GHz, maps are corrected for zero level monopole by applying an offset correction, see LFI Calibration paper {{PlanckPapers|planck2014-a06}}. Note that the offset applied is indicated in the header as a comment keyword.<br />
<br />
A detailed description of the map-making procedure is given in {{PlanckPapers|planck2013-p02}}, {{PlanckPapers|planck2014-a03}}, {{PlanckPapers|planck2014-a07}} and in section [[Map-making LFI#Map-making|Map-making]].<br />
<br />
'''Types of maps '''<br />
<br />
''' Full mission, full channel maps (6 HFI, 4 LFI)'''<br />
<br />
Full channel maps are built using all the valid detectors of a frequency channel and cover the either the full or the nominal mission. For HFI, the 143-8 and 545-3 bolometers are rejected entirely as they are seriously affected by RTS noise. HFI provides the Q and U components for the 100, 143, 217 and 353 GHz channels only. LFI provides the I, Q and U maps for all the channels. Reminder: HFI Q and U maps are corrected for bandpass leakage but LFI Q and U maps are not. The I, Q and U maps are displayed in the figures below. The color range is set using a histogram equalisation scheme (from HEALPIX) that is useful for these non-Gaussian data fields. For visualization purposes, the Q and U maps shown here have been smoothed with a 1 degree Gaussian kernel, otherwise they look like noise to the naked eye.<br />
The 70 GHz full map is available also at <math>N_{side}</math> 2048.<br />
<br />
<center><br />
<gallery style="padding:0 0 0 0;" perrow=3 widths=260px heights=160px> <br />
File: SkyMap30e.png| '''Full mission I, 30 GHz'''<br />
File: SkyMap44e.png | '''Full mission I, 44 GHz'''<br />
File: SkyMap70e.png | '''Full mission I, 70 GHz'''<br />
File: SkyMap100e.png | '''Full mission I, 100 GHz'''<br />
File: SkyMap143e.png | '''Full mission I, 143 GHz'''<br />
File: SkyMap217e.png | '''Full mission I, 217 GHz'''<br />
File: SkyMap353e.png | '''Full mission I, 353 GHz'''<br />
File: SkyMap545e.png | '''Full mission I, 545 GHz'''<br />
File: SkyMap857e.png | '''Full mission I, 857 GHz'''<br />
</gallery><br />
</center><br />
<br><br />
<center><br />
<gallery style="padding:0 0 0 0;" perrow=3 widths=260px heights=160px> <br />
File: LFI_SkyMap_030_1024_R2.01_full_Qb_sm1deg.png| '''Full mission Q, 30 GHz'''<br />
File: LFI_SkyMap_044_1024_R2.01_full_Qb_sm1deg.png | '''Full mission Q, 44 GHz'''<br />
File: LFI_SkyMap_070_1024_R2.01_full_Qb_sm1deg.png | '''Full mission Q, 70 GHz'''<br />
File: HFI_Skymap_100_full_bplcorrected_sm1deg_Qb.png | '''Full mission Q, 100 GHz'''<br />
File: HFI_Skymap_143_full_bplcorrected_sm1deg_Qb.png | '''Full mission Q, 143 GHz'''<br />
File: HFI_Skymap_217_full_bplcorrected_sm1deg_Qb.png | '''Full mission Q, 217 GHz'''<br />
File: HFI_Skymap_353_full_bplcorrected_sm1deg_Qb.png | '''Full mission Q, 353 GHz'''<br />
</gallery><br />
</center><br />
<br><br />
<center><br />
<gallery style="padding:0 0 0 0;" perrow=3 widths=260px heights=160px> <br />
File: LFI_SkyMap_030_1024_R2.01_full_Ub_sm1deg.png| '''Full mission U, 30 GHz'''<br />
File: LFI_SkyMap_044_1024_R2.01_full_Ub_sm1deg.png | '''Full mission U, 44 GHz'''<br />
File: LFI_SkyMap_070_1024_R2.01_full_Ub_sm1deg.png | '''Full mission U, 70 GHz'''<br />
File: HFI_Skymap_100_full_bplcorrected_sm1deg_Ub.png | '''Full mission U, 100 GHz'''<br />
File: HFI_Skymap_143_full_bplcorrected_sm1deg_Ub.png | '''Full mission U, 143 GHz'''<br />
File: HFI_Skymap_217_full_bplcorrected_sm1deg_Ub.png | '''Full mission U, 217 GHz'''<br />
File: HFI_Skymap_353_full_bplcorrected_sm1deg_Ub.png | '''Full mission U, 353 GHz'''<br />
</gallery><br />
<br />
</center><br />
<br />
''' Full mission light maps, full channel maps (6 HFI, 7 LFI) '''<br />
<br />
These maps are based on the Full mission maps but contain fewer columns, IQU from 30 to 353 GHz, and I only at 545 and 857 GHz. These maps have been produced to reduce the transfer time of the most downloaded frequency full mission maps.<br />
<br />
''' Nominal mission, full channel maps (6 HFI) '''<br />
<br />
These maps are similar to the ones above, but cover the nominal mission only. They are meant primarily to be compared to the PR1 products in order to see the level of improvements in the processing. Because of this, they are produced in Temperature only, and have not had the post-processing applied.<br />
<br />
''' Single survey, full channel maps (30 HFI, 35 LFI)'''<br />
<br />
Single survey maps are built using all valid detectors of a frequency channel; they cover separately the different sky surveys. The surveys are defined as the times over which the satellite spin axis rotates but 180 degrees, which, due to the position of the detectors in the focal plane does not cover the full sky, but a fraction between ~80 and 90% depending on detector position. During adjacent surveys the sky is scanned in opposite directions. More precisely it is the ecliptic equator that is scanned in opposite directions. While these are useful to investigate variable sources, they are also used to study the systematics of the time-response of the detectors as they scan bright sources, like the Galactic Plane, in different directions during different survey. Note that the HFI and LFI missions cover 5 and 8 surveys, respectively, and in case of HFI the last survey in incomplete.<br />
The 70 GHz surveys maps are available also at <math>N_{side}</math> 2048.<br />
Note LFI provide a special surveys maps combination used in the low l analysis. This maps, available at the three LFI frequency 30, 44 and 70 GHz, was built using the combination of survey 1, 3, 5, 6, 7 and 8. <br />
<br />
''' Year maps, full channel maps (12 HFI, 16 LFI)'''<br />
<br />
These maps are built using the data of surveys 1+2, surveys 3+4, and so forth. They are used to study long-term systematic effects.<br />
The 70 GHz years maps are available also at <math>N_{side}</math> 2048.<br />
<br />
'''Half-mission maps, full channel maps (12 HFI, 12 LFI)'''<br />
<br />
For HFI, the half mission is defined after eliminating those rings discarded for all bolometers. There are 347 such rings, may of which are during the 5th survey when the ''End-of-Life'' tests were performed. The remaining 26419 rings are divided in half (up to the odd ring) to define the two halves of the mission. This exercise is done for the full mission only.<br />
<br />
For LFI instead of the half-mission the following year combination has been created: Year 1+2, Year 1+3, Year 2+4, Year 3+4, <br />
<br />
'''Full mission, single detector maps (18 HFI, 22 LFI)'''<br />
<br />
IN case of HFI these maps are built only for the SWBs (non polarized) and contain only temperature data, of course. They are not built for the polarisation sensitive detectors because they are not fixed on the sky as the polarisation component depends on the position angle at the time of observation. Instead, we provide maps built by ''quads'' of polarisation-sensitive detectors (see next section), which have different polarisation angles and that can be used to built I, Q, and U maps<br />
<br />
{| border="1" cellpadding="3" cellspacing="0" align="center" style="text-align:left" width=600px<br />
|+ '''HFI Temperature sensitive bolometers'''<br />
|- bgcolor="ffdead" <br />
!Frequency || Detector names<br />
|-<br />
|143 GHz || 143-5, 6, 7<br />
|-<br />
|217 GHz || 217-1, 2, 3, 4<br />
|-<br />
|353 GHz || 353-1, 2, 7, 8<br />
|-<br />
|545 GHz || 545-1, 2, 4<br />
|-<br />
|857 GHz || 857-1, 2 , 3, 4<br />
|}<br />
<br />
The 143-8 and 353-3 bolometer data are affected by strong RTS (random telegraphic signal) noise. They have not been used in the data processing, and are not delivered. For a figure showing the focal plane layout, see [[Detector_pointing#Introduction_and_Summary | this Introduction]] of the Detector Pointing chapter.<br />
<br />
In case of LFI, all the 22 Radiometers maps are available, those, obviously, are only in temperature.<br />
<br />
'''Full mission, detector set or detector pairs maps (8 HFI, 8 LFI)'''<br />
<br />
The objective here is to build independent temperature (I) and polarisation (Q and U) maps with the two pairs of polarisation sensitive detectors of each channel where they are available, i.e. in the 44-353 GHz channels. The table below indicates which detectors were used to built each detector set (detset).<br />
<br />
<br />
{| border="1" cellpadding="3" cellspacing="0" align="center" style="text-align:left" width=600px<br />
|+ '''Definition of HFI Detector Sets'''<br />
|- bgcolor="ffdead" <br />
!Frequency || DetSet1 || DetSet2 <br />
|-<br />
|100 GHz || 100-1a/b & 100-4a/b || 100-2a/b & 100-3a/b<br />
|-<br />
|143 GHz || 143-1a/b 1 & 43-3a/b || 143-2a/b & 143-4a/b<br />
|-<br />
|217 GHz || 217-5a/b & 217-7a/b || 217-6a/b & 217-8a/b<br />
|-<br />
|353 GHz || 353-3a/b & 353-5a/b || 353-4a/b & 353-6a/b<br />
|}<br />
<br />
{| border="1" cellpadding="3" cellspacing="0" align="center" style="text-align:left" width=600px<br />
|+ '''Definition of LFI Detector Pairs'''<br />
|- bgcolor="ffdead" <br />
!Frequency || Horn Pair || Comment <br />
|-<br />
|44 GHz || 24 || This maps is only in temperature<br />
|-<br />
|44 GHz || 25 & 26 || <br />
|-<br />
|70 GHz || 18 & 23 || Available also at <math>N_{side}</math> = 2048<br />
|-<br />
|70 GHz || 19 & 22 || Available also at <math>N_{side}</math> = 2048<br />
|-<br />
|70 GHz || 20 & 21 || Available also at <math>N_{side}</math> = 2048<br />
|}<br />
<br />
<br />
'''Half-ring maps (64 HFI, 62 LFI)'''<br />
<br />
These maps are similar to the ones above, but are built using only the first or the second half of each ring (or pointing period). The HFI provides half-ring maps for the full mission only, and for the full channel, the detsets, and the single bolometers. The LFI provides half-rings maps for the channel full mission (70 GHz also at <math>N_{side}</math> 2048), for the radiometer full mission and the horn pairs full mission.<br />
<!----<br />
'''Masks'''<br />
<br />
Masks are provided of the Galactic Plane and of the point sources. For the Galactic Plane, eight masks are given covering different fractions of the sky, and for the points sources two masks are given, at the 5 and 10 sigma level, for each Planck HFI and LFI frequency channel. These are generic masks, specific masks applicable to other products are delivered with the products themselves.<br />
---><br />
<br />
''' The Zodiacal light correction maps '''<br />
<br />
The Zodiacal light signal depends on the location of the observer relative to the Zodiacal light bands, and thus it is not a fixed pattern on the sky but depends on the period of observation. The maps presented here are the difference between the uncorrected (and not delivered) and the corrected maps. <br />
<br />
Note that while the Zodiacal light model that is subtracted at ring level (see [[Map-making#Zodiacal_light_correction | here]]) is not polarised, the corrections are not null and Q and U. This is suspected to come from some combination of leakage due to bandpass differences and beam mismatch, and maybe other effects. These leakages are typically of order a few %, at max, of the maximum zodi intensity at I for each channel. They range from ~150 nK at 100 GHz to ~5 uK at 353 GHz.<br />
<br />
''' Caveats and known issues '''<br />
<br />
; HFI polarization 100-217 GHz : at low multipoles, despite the progress that has been made to control the systematic effects present in the maps, polarization data between 100-217 GHz are still contaminated by systematic residuals. Figure 10 of {{PlanckPapers|planck2014-a09}} shows the EE power spectra from the half-difference maps at 100, 143, and 217 GHz and compared to the noise power spectrum from FFP8 simulations. he half-ring differences are compatible with noise while, at multipoles typically lower than 50, detector-set and half-mission differences are dominated by excess power which is larger than the EE CMB signal. The Planck Collaboration has used the range ell>30 to carry out component separation ({{PlanckPapers|planck2014-a11}}), as data at ell<30 is not considered usable for cosmological analyses. The origin of the excess power will be explored in a forthcoming publication.<br />
<br />
<br />
'''Inputs'''<br />
''' HFI inputs '''<br />
<br />
The HFI mapmaking takes as input:<br />
* the cleaned TOIs of signal of each detector, together with their flags, produced by the [[TOI processing|TOI processing]] pipeline;<br />
* the TOIs of pointing (quaternions), described in [[Detector_pointing|Detector pointing]];<br />
* bolometer-level characterization data, from the DPC's internal IMO (not distributed);<br />
* Planck orbit data, used to compute and remove the Earth's dipole;<br />
* Planck solar dipole information, used to calibrate the CMB channels;<br />
* Planet models used to calibrate the Galactic channels.<br />
<br />
''' LFI inputs '''<br />
<br />
The Madam mapmaker takes as input:<br />
<br />
* the calibrated timelines (for details see [[TOI processing LFI|TOI Processing]]);<br />
* the detector pointings (for details see [[Detector_pointing|Detector pointing]]);<br />
* the noise information in the form of 3-parameter (white noise level, &sigma;, slope, and knee frequency, <i>f</i><sub>knee</sub>) noise model (for details see [[The RIMO|RIMO]])<br />
<br />
'''Related products'''<br />
''' Masks '''<br />
<br />
This section presents the masks of the point sources and of the Galactic plane. These are ''general purpose'' masks. Other masks specific to certain products are packaged with the products.<br />
<br />
'''Point source masks'''<br />
<br />
For HFI and LFI two sets of masks are provided: <br />
* Intensity masks, which removes sources detected with SNR > 5. <br />
* Polarisation masks, which remove sources which have polarisation detection significance of 99.97 % or greater at the position of a source detected in intensity. They were derived from the polarisation maps with dust ground bandpass mismatch leakage correction applied. The cut around each source has a radius of 3σ (width) of the beam ~ 1.27 FWHM (for LFI the cut around each source has a radius of 32 arcmin at 30GHz, 27 arcmin at 44 GHz and 13 arcmin at 70 GHz).<br />
<br />
Both sets are found in the files ''HFI_Mask_PointSrc_2048_R2.00.fits'' and ''LFI_Mask_PointSrc_2048_R2.00.fits'' in which the first extension contains the Intensity masks, and the second contains the Polarisation masks.<br />
<br />
'''Galactic plane masks'''<br />
<br />
Eight masks are provided giving 20, 40, 60, 70, 80, 90, 97, and 99% sky coverage derived from the 353 GHz map, after CMB subtraction. They are independent of frequency channel. Three versions of these are given: not apodized, and apodized by 2 and 5 deg. The filenames are ''HFI_Mask_GalPlane-apoN_2048_R2.00.fits'', where N = 0, 2, 5.<br />
<br />
The masks are shows below. The 8 GalPlane masks are combined (added together) and shown in a single figure for each of the three apodization. While the result is quite clear for the case of no apodization, it is less so for the apodized case. The point source masks are shown separately for the Intensity case.<br />
<br />
<center><br />
<gallery perrow=3 widths=260px heights=160px ><br />
File: GalPlaneMask_apo0.png | '''Galactic Plane masks, no apod'''<br />
File: GalPlaneMask_apo2.png | '''Galactic Plane masks, apod 2 deg'''<br />
File: GalPlaneMask_apo5.png | '''Galactic Plane masks, apod 5 deg'''<br />
File: PointSrcMask_100.png | '''PointSource mask 100 GHz'''<br />
File: PointSrcMask_143.png | '''PointSource mask 143 GHz'''<br />
File: PointSrcMask_217.png | '''PointSource mask 217 GHz'''<br />
File: PointSrcMask_353.png | '''PointSource mask 343 GHz'''<br />
File: PointSrcMask_545.png | '''PointSource mask 545 GHz'''<br />
File: PointSrcMask_857.png | '''PointSource mask 857 GHz'''<br />
</gallery><br />
</center><br />
<br />
''' File names '''<br />
The FITS filenames are of the form ''{H|L}FI_SkyMap_fff{-tag}_Nside_R2.nn_{coverage}-{type}.fits'', where ''fff'' are three digits to indicate the Planck frequency band, ''tag'' indicates the single detector or the detset, ''Nside'' is the Healpix Nside of the map, ''coverage'' indicates which part of the mission is covered (full, half mission, survey, year, ...) , and the optional ''type'' indicates the subset of input data used. The table below lists the products by type, with the appropriate unix wildcards that form the full filename.<br />
<br />
{| class="wikitable" align="center" style="text-align"left" border="1" cellpadding="15" cellspacing="20" width=880px<br />
|+ '''HFI FITS filenames'''<br />
|- bgcolor="ffdead"<br />
! Coverage || filename || half-ring filename <br />
|-<br />
| Full chan, full mission ||HFI_SkyMap_???_2048_R2.??_full.fits ||HFI_SkyMap_???_2048_R2.??_full-ringhalf-?.fits<br />
|-<br />
| Full channel, nominal mission ||HFI_SkyMap_???_2048_R2.??_nominal.fits || n/a<br />
|-<br />
| Full channel, single survey || HFI_SkyMap_???_2048_R2.??_survey-?.fits || n/a<br />
|-<br />
| Full channel, single year || HFI_SkyMap_???_2048_R2.??_year-?.fits || n/a<br />
|-<br />
| Full channel, half mission || HFI_SkyMap_???_2048_R2.??_halfmission*-?.fits || n/a<br />
|-<br />
| Det-set, full mission || HFI_SkyMap_???-ds?_2048_R2.??_full.fits || HFI_SkyMap_???-ds?_2048_R2.??_full-ringhalf-?.fits<br />
|-<br />
|Single SWB, full mission || HFI_SkyMap_???-?_2048_R2.??_full.fits || HFI_SkyMap_???-?_2048_R2.??_full-ringhalf-?.fits<br />
|}<br />
<br />
{| class="wikitable" align="center" style="text-align"left" border="1" cellpadding="15" cellspacing="20" width=1000px<br />
|+ '''LFI FITS filenames'''<br />
|- bgcolor="ffdead"<br />
! Coverage || filename || half-ring filename || Comment<br />
|-<br />
| Full channel, full mission ||LFI_SkyMap_???_1024_R2.??_full.fits ||LFI_SkyMap_???_1024_R2.??_full-ringhalf-?.fits || Available also at Nside = 2048<br />
|-<br />
| Full channel, single survey || LFI_SkyMap_???_1024_R2.??_survey-?.fits || n/a || Available also at Nside = 2048<br />
|-<br />
| Full channel, survey combination || LFI_SkyMap_???_1024_R2.??_survey-1-3-5-6-7-8.fits || n/a || n/a<br />
|-<br />
| Full channel, single year || LFI_SkyMap_???_1024_R2.??_year-?.fits || n/a || Available also at Nside = 2048<br />
|-<br />
| Full channel, year combination || LFI_SkyMap_???_1024_R2.??_year?-?.fits || n/a || n/a<br />
|-<br />
| Horn pair, full mission || LFI_SkyMap_???-??-??_1024_R2.??_full.fits || LFI_SkyMap_???_??-??_1024_R2.??_full-ringhalf-?.fits || Available also at Nside = 2048<br />
|-<br />
| Single radiometer, full mission || LFI_SkyMap_???-???_1024_R2.??_full.fits || LFI_SkyMap_???-???_1024_R2.??_full-ringhalf-?.fits || n/a<br />
|}<br />
<br />
<br />
<br />
For the benefit of users who are only looking for the frequency maps with no additional information, we also provide a file combining the 9 frequency maps as separate columns in a single extension. The 9 columns in this file contain the intensity maps ONLY and no other information (hit maps and variance maps) is provided.<br />
<br />
<!---<br />
{| class="wikitable" align="center" style="text-align:center" border="1" cellpadding="3" cellspacing="0" width=500px<br />
|+ '''FITS filenames'''<br />
|- bgcolor="ffdead"<br />
! Frequency || Full channel maps<br />
|-<br />
| '''30GHz''' || {{PLASingleFile|fileType=map|name=LFI_SkyMap_030_1024_R1.10_nominal.fits|link=LFI_SkyMap_030_1024_R1.10_nominal.fits}}<br />
|-<br />
| '''44GHz''' || {{PLASingleFile|fileType=map|name=LFI_SkyMap_044_1024_R1.10_nominal.fits|link=LFI_SkyMap_044_1024_R1.10_nominal.fits}}<br />
|-<br />
| '''70GHz''' || {{PLASingleFile|fileType=map|name=LFI_SkyMap_070_1024_R1.10_nominal.fits|link=LFI_SkyMap_070_1024_R1.10_nominal.fits}}<br />
|-<br />
| '''70GHz''' || {{PLASingleFile|fileType=map|name=LFI_SkyMap_070_2048_R1.10_nominal.fits|link=LFI_SkyMap_070_2048_R1.10_nominal.fits}}<br />
|-<br />
| '''100GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_100_2048_R1.10_nominal.fits|link=HFI_SkyMap_100_2048_R1.10_nominal.fits}}<br />
|-<br />
| '''143GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_143_2048_R1.10_nominal.fits|link=HFI_SkyMap_143_2048_R1.10_nominal.fits}}<br />
|-<br />
| '''217GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_217_2048_R1.10_nominal.fits|link=HFI_SkyMap_217_2048_R1.10_nominal.fits}}<br />
|-<br />
| '''353GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_353_2048_R1.10_nominal.fits|link=HFI_SkyMap_353_2048_R1.10_nominal.fits}}<br />
|-<br />
| '''545GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_545_2048_R1.10_nominal.fits|link=HFI_SkyMap_545_2048_R1.10_nominal.fits}}<br />
|-<br />
| '''857GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_857_2048_R1.10_nominal.fits|link=HFI_SkyMap_857_2048_R1.10_nominal.fits}}<br />
|- bgcolor="ffdead"<br />
! Frequency || Full channel, Zodi-corrected maps<br />
|-<br />
| '''100GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_100_2048_R1.10_nominal_ZodiCorrected.fits|link=HFI_SkyMap_100_2048_R1.10_nominal_ZodiCorrected.fits}} <br />
|-<br />
| '''143GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_143_2048_R1.10_nominal_ZodiCorrected.fits|link=HFI_SkyMap_143_2048_R1.10_nominal_ZodiCorrected.fits}}<br />
|-<br />
| '''217GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_217_2048_R1.10_nominal_ZodiCorrected.fits|link=HFI_SkyMap_217_2048_R1.10_nominal_ZodiCorrected.fits}}<br />
|-<br />
| '''353GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_353_2048_R1.10_nominal_ZodiCorrected.fits|link=HFI_SkyMap_353_2048_R1.10_nominal_ZodiCorrected.fits}}<br />
|-<br />
| '''545GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_545_2048_R1.10_nominal_ZodiCorrected.fits|link=HFI_SkyMap_545_2048_R1.10_nominal_ZodiCorrected.fits}}<br />
|-<br />
| '''857GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_857_2048_R1.10_nominal_ZodiCorrected.fits|link=HFI_SkyMap_857_2048_R1.10_nominal_ZodiCorrected.fits}}<br />
|- bgcolor="ffdead"<br />
! Frequency || Combined frequency maps<br />
|-<br />
| '''All''' || {{PLASingleFile|fileType=file|name=COM_MapSet_I-allFreqs_R1.10_nominal.fits|link=COM_MapSet_I-allFreqs_R1.10_nominal.fits}} <br />
|}<br />
<br />
<br />
{| class="wikitable" align="center" style="text-align:center" border="1" cellpadding="3" cellspacing="0" width=850px<br />
|+ '''FITS filenames'''<br />
|- bgcolor="ffdead"<br />
! Frequency || Survey 1 maps || Survey 2 maps<br />
|-<br />
| '''30GHz''' || {{PLASingleFile|fileType=map|name=LFI_SkyMap_030_1024_R1.10_survey_1.fits|link=LFI_SkyMap_030_1024_R1.10_survey_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=LFI_SkyMap_030_1024_R1.10_survey_2.fits|link=LFI_SkyMap_030_1024_R1.10_survey_2.fits}}<br />
|-<br />
| '''44GHz''' || {{PLASingleFile|fileType=map|name=LFI_SkyMap_044_1024_R1.10_survey_1.fits|link=LFI_SkyMap_044_1024_R1.10_survey_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=LFI_SkyMap_044_1024_R1.10_survey_2.fits|link=LFI_SkyMap_044_1024_R1.10_survey_2.fits}}<br />
|-<br />
| '''70GHz''' || {{PLASingleFile|fileType=map|name=LFI_SkyMap_070_1024_R1.10_survey_1.fits|link=LFI_SkyMap_070_1024_R1.10_survey_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=LFI_SkyMap_070_1024_R1.10_survey_2.fits|link=LFI_SkyMap_070_1024_R1.10_survey_2.fits}}<br />
|-<br />
| '''70GHz''' || {{PLASingleFile|fileType=map|name=LFI_SkyMap_070_2048_R1.10_survey_1.fits|link=LFI_SkyMap_070_2048_R1.10_survey_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=LFI_SkyMap_070_2048_R1.10_survey_2.fits|link=LFI_SkyMap_070_2048_R1.10_survey_2.fits}}<br />
|-<br />
| '''100GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_100_2048_R1.10_survey_1.fits|link=HFI_SkyMap_100_2048_R1.10_survey_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_100_2048_R1.10_survey_2.fits|link=HFI_SkyMap_100_2048_R1.10_survey_2.fits}}<br />
|-<br />
| '''143GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_143_2048_R1.10_survey_1.fits|link=HFI_SkyMap_143_2048_R1.10_survey_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_143_2048_R1.10_survey_2.fits|link=HFI_SkyMap_143_2048_R1.10_survey_2.fits}}<br />
|-<br />
| '''217GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_217_2048_R1.10_survey_1.fits|link=HFI_SkyMap_217_2048_R1.10_survey_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_217_2048_R1.10_survey_2.fits|link=HFI_SkyMap_217_2048_R1.10_survey_2.fits}}<br />
|-<br />
| '''353GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_353_2048_R1.10_survey_1.fits|link=HFI_SkyMap_353_2048_R1.10_survey_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_353_2048_R1.10_survey_2.fits|link=HFI_SkyMap_353_2048_R1.10_survey_2.fits}}<br />
|-<br />
| '''545GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_545_2048_R1.10_survey_1.fits|link=HFI_SkyMap_545_2048_R1.10_survey_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_545_2048_R1.10_survey_2.fits|link=HFI_SkyMap_545_2048_R1.10_survey_2.fits}}<br />
|-<br />
| '''857GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_857_2048_R1.10_survey_1.fits|link=HFI_SkyMap_857_2048_R1.10_survey_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_857_2048_R1.10_survey_2.fits|link=HFI_SkyMap_857_2048_R1.10_survey_2.fits}}<br />
|- bgcolor="ffdead"<br />
! Frequency || Survey 1 Zodi-corrected maps || Survey 2 Zodi-corrected maps<br />
|-<br />
| '''100GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_100_2048_R1.10_survey_1_ZodiCorrected.fits|link=HFI_SkyMap_100_2048_R1.10_survey_1_ZodiCorrected.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_100_2048_R1.10_survey_2_ZodiCorrected.fits|link=HFI_SkyMap_100_2048_R1.10_survey_2_ZodiCorrected.fits}}<br />
|-<br />
| '''143GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_143_2048_R1.10_survey_1_ZodiCorrected.fits|link=HFI_SkyMap_143_2048_R1.10_survey_1_ZodiCorrected.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_143_2048_R1.10_survey_2_ZodiCorrected.fits|link=HFI_SkyMap_143_2048_R1.10_survey_2_ZodiCorrected.fits}}<br />
|-<br />
| '''217GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_217_2048_R1.10_survey_1_ZodiCorrected.fits|link=HFI_SkyMap_217_2048_R1.10_survey_1_ZodiCorrected.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_217_2048_R1.10_survey_2_ZodiCorrected.fits|link=HFI_SkyMap_217_2048_R1.10_survey_2_ZodiCorrected.fits}}<br />
|-<br />
| '''353GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_353_2048_R1.10_survey_1_ZodiCorrected.fits|link=HFI_SkyMap_353_2048_R1.10_survey_1_ZodiCorrected.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_353_2048_R1.10_survey_2_ZodiCorrected.fits|link=HFI_SkyMap_353_2048_R1.10_survey_2_ZodiCorrected.fits}}<br />
|-<br />
| '''545GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_545_2048_R1.10_survey_1_ZodiCorrected.fits|link=HFI_SkyMap_545_2048_R1.10_survey_1_ZodiCorrected.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_545_2048_R1.10_survey_2_ZodiCorrected.fits|link=HFI_SkyMap_545_2048_R1.10_survey_2_ZodiCorrected.fits}}<br />
|-<br />
| '''857GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_857_2048_R1.10_survey_1_ZodiCorrected.fits|link=HFI_SkyMap_857_2048_R1.10_survey_1_ZodiCorrected.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_857_2048_R1.10_survey_2_ZodiCorrected.fits|link=HFI_SkyMap_857_2048_R1.10_survey_2_ZodiCorrected.fits}}<br />
|- bgcolor="ffdead"<br />
! Frequency || Half-ring 1 maps ||Half-ring 2 maps<br />
|-<br />
| '''30GHz''' || {{PLASingleFile|fileType=map|name=LFI_SkyMap_030_1024_R1.10_nominal_ringhalf_1.fits|link=LFI_SkyMap_030_1024_R1.10_nominal_ringhalf_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=LFI_SkyMap_030_1024_R1.10_nominal_ringhalf_2.fits|link=LFI_SkyMap_030_1024_R1.10_nominal_ringhalf_2.fits}}<br />
|-<br />
| '''44GHz''' || {{PLASingleFile|fileType=map|name=LFI_SkyMap_044_1024_R1.10_nominal_ringhalf_1.fits|link=LFI_SkyMap_044_1024_R1.10_nominal_ringhalf_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=LFI_SkyMap_044_1024_R1.10_nominal_ringhalf_2.fits|link=LFI_SkyMap_044_1024_R1.10_nominal_ringhalf_2.fits}}<br />
|-<br />
| '''70GHz''' || {{PLASingleFile|fileType=map|name=LFI_SkyMap_070_1024_R1.10_nominal_ringhalf_1.fits|link=LFI_SkyMap_070_1024_R1.10_nominal_ringhalf_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=LFI_SkyMap_070_1024_R1.10_nominal_ringhalf_2.fits|link=LFI_SkyMap_070_1024_R1.10_nominal_ringhalf_2.fits}}<br />
|-<br />
| '''70GHz''' || {{PLASingleFile|fileType=map|name=LFI_SkyMap_070_2048_R1.10_nominal_ringhalf_1.fits|link=LFI_SkyMap_070_2048_R1.10_nominal_ringhalf_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=LFI_SkyMap_070_2048_R1.10_nominal_ringhalf_2.fits|link=LFI_SkyMap_070_2048_R1.10_nominal_ringhalf_2.fits}}<br />
|-<br />
| '''100GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_100_2048_R1.10_nominal_ringhalf_1.fits|link=HFI_SkyMap_100_2048_R1.10_nominal_ringhalf_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_100_2048_R1.10_nominal_ringhalf_2.fits|link=HFI_SkyMap_100_2048_R1.10_nominal_ringhalf_2.fits}}<br />
|-<br />
| '''143GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_143_2048_R1.10_nominal_ringhalf_1.fits|link=HFI_SkyMap_143_2048_R1.10_nominal_ringhalf_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_143_2048_R1.10_nominal_ringhalf_2.fits|link=HFI_SkyMap_143_2048_R1.10_nominal_ringhalf_2.fits}}<br />
|-<br />
| '''217GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_217_2048_R1.10_nominal_ringhalf_1.fits|link=HFI_SkyMap_217_2048_R1.10_nominal_ringhalf_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_217_2048_R1.10_nominal_ringhalf_2.fits|link=HFI_SkyMap_217_2048_R1.10_nominal_ringhalf_2.fits}}<br />
|-<br />
| '''353GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_353_2048_R1.10_nominal_ringhalf_1.fits|link=HFI_SkyMap_353_2048_R1.10_nominal_ringhalf_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_353_2048_R1.10_nominal_ringhalf_2.fits|link=HFI_SkyMap_353_2048_R1.10_nominal_ringhalf_2.fits}}<br />
|-<br />
| '''545GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_545_2048_R1.10_nominal_ringhalf_1.fits|link=HFI_SkyMap_545_2048_R1.10_nominal_ringhalf_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_545_2048_R1.10_nominal_ringhalf_2.fits|link=HFI_SkyMap_545_2048_R1.10_nominal_ringhalf_2.fits}}<br />
|-<br />
| '''857GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_857_2048_R1.10_nominal_ringhalf_1.fits|link=HFI_SkyMap_857_2048_R1.10_nominal_ringhalf_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_857_2048_R1.10_nominal_ringhalf_2.fits|link=HFI_SkyMap_857_2048_R1.10_nominal_ringhalf_2.fits}}<br />
|}<br />
---><br />
<br />
''' FITS file structure '''<br />
<br />
The FITS files for the sky maps contain a minimal primary header with no data, and a ''BINTABLE'' extension (EXTENSION 1, EXTNAME = ''FREQ-MAP'') containing the data. The structure is shows schematically in the figure below. The ''FREQ-MAP'' extension contains a 3- or a 10-column table that contain the signal, hit-count and variance maps, all in Healpix format. The 3-column case is for intensity only maps, the 10-column case is for polarisation. The number of rows is the number of map pixels, which is Npix = 12 <math>N_{side}</math><sup>2</sup> for Healpix maps, where <math>N_{side}</math> = 1024 or 2048 for most the maps presented in this chapter.<br />
<br />
[[File:FITS_FreqMap.png | 550px | center | thumb | '''FITS file structure''']]<br />
<br />
Note that file sizes are ~0.6 GB for I-only maps and ~1.9 GB for I,Q,U maps at <math>N_{side}</math> 2048 and ~0.14 GB for I-only maps and ~0.45 GB for I,Q,U maps at <math>N_{side}</math> 1024 .<br />
<br />
Keywords indicate the coordinate system (GALACTIC), the Healpix ordering scheme (NESTED), the units (K_cmb or MJy/sr) of each column, and of course the frequency channel (FREQ). Where polarisation Q and U maps are provided, the ''COSMO'' polarisation convention (used in HEALPIX) is adopted, and it is specified in the ''POLCCONV'' keyword (see [[Sky_temperature_maps#Polarization_convention_used_in_the_Planck_project|this section]]. The COMMENT fields give a one-line summary of the product, and some other information useful for traceability within the DPCs. The original filename is also given in the ''FILENAME'' keyword. The ''BAD_DATA'' keyword gives the value used by Healpix to indicate pixels for which no signal is present (these will also have a hit-count value of 0). The main parameters are summarised below:<br />
<br />
<br />
{| border="1" cellpadding="3" cellspacing="0" align="center" style="text-align:left" width=800px<br />
|+ '''Sky map file data structure'''<br />
|- bgcolor="ffdead" <br />
!colspan="4" | 1. EXTNAME = 'FREQ-MAP' : Data columns<br />
|- bgcolor="ffdead" <br />
! Column Name || Data Type || Units || Description<br />
|-<br />
|I_STOKES || Real*4 || K_cmb or MJy/sr || The Stokes I map<br />
|-<br />
|Q_STOKES || Real*4 || K_cmb or MJy/sr || The Stokes Q map (optional)<br />
|-<br />
|U_STOKES || Real*4 || K_cmb or MJy/sr || The Stokes U map (optional)<br />
|-<br />
|HITS || Int*4 || none || The hit-count map<br />
|-<br />
|II_COV || Real*4 || K_cmb<sup>2</sup> or (MJy/sr)<sup>2</sup> || The II variance map<br />
|-<br />
|IQ_COV || Real*4 || K_cmb<sup>2</sup> or (MJy/sr)<sup>2</sup> || The IQ variance map (optional)<br />
|-<br />
|IU_COV || Real*4 || K_cmb<sup>2</sup> or (MJy/sr)<sup>2</sup> || The IQ variance map (optional)<br />
|-<br />
|QQ_COV || Real*4 || K_cmb<sup>2</sup> or (MJy/sr)<sup>2</sup> || The QQ variance map (optional)<br />
|-<br />
|QU_COV || Real*4 || K_cmb<sup>2</sup> or (MJy/sr)<sup>2</sup> || The QU variance map (optional)<br />
|-<br />
|UU_COV || Real*4 || K_cmb<sup>2</sup> or (MJy/sr)<sup>2</sup> || The UU variance map (optional)<br />
|-<br />
|- bgcolor="ffdead" <br />
! Keyword || Data Type || Value || Description<br />
|-<br />
|PIXTYPE || string || HEALPIX ||<br />
|-<br />
|COORDSYS || string || GALACTIC ||Coordinate system <br />
|-<br />
|ORDERING || string || NESTED || Healpix ordering<br />
|-<br />
|POLCCONV || String || COSMO || Polarization convention<br />
|-<br />
|NSIDE || Int || 1024 or 2048 || Healpix <math>N_{side}</math> <br />
|-<br />
|FIRSTPIX || Int*4 || 0 || First pixel number<br />
|-<br />
|LASTPIX || Int*4 || 12 <math>N_{side}</math><sup>2</sup> – 1 || Last pixel number<br />
|-<br />
|FREQ || string || nnn || The frequency channel <br />
|}<br />
<br />
<br />
The same structure applies to all ''SkyMap'' products, independent of whether they are full channel, survey of half-ring. The distinction between the types of maps is present in the FITS filename (and in the traceability comment fields).<br />
<br />
'''Polarization convention used in the Planck project'''<br />
<br />
The Planck collaboration used the COSMO convention for the polarization angle (as usually used in space based CMB missions), whereas other astronomical fields usually use the IAU convention. In the following document we report the difference between these two conventions, and the consequence if it is NOT taken into account correctly in the analysis.<br />
<br />
[[File:conventions.png|thumb|center|400px|'''Figure 1. COSMO convention (left) and IAU convention (right). The versor <math>\hat{z}</math> points outwards the pointing direction in COSMO, and inwards in IAU. The bottom panel refers to the plane tangent to the sphere.''']]<br />
<br />
Changing the orientation convention is equivalent to a transformation <math>\psi'=\pi-\psi</math> of the polarization angle (Figure 1). The consequence of this transformation is the inversion of the Stokes parameter <math>U</math>.<br />
The components of the polarization tensor in the helicity basis <math>\epsilon^{\pm}=1/\sqrt{2}(\hat{x}\pm i\hat{y})</math> are:<br />
<br />
<math><br />
(Q+iU)(\hat{n}) = \sum _{\ell m}a_{2,lm}{}_{2}Y_{\ell }^{m}(\hat{n})<br />
\\(Q-iU)(\hat{n}) = \sum _{\ell m}a_{-2,lm}{}_{2}Y_{\ell }^{m}(\hat{n})<br />
</math><br />
<br />
where <math>{}_{2}Y_{\ell }^{m}(\hat{n})</math> are the spin weighted spherical harmonic functions.<br />
The <math>E</math> and <math>B</math> modes can be defined as:<br />
<math><br />
E(\hat{n}) = \sum_{\ell m}a_{E,\ell m}Y_{\ell }^{m}(\hat{n})<br />
\\B(\hat{n}) = \sum_{\ell m}a_{B,\ell m}Y_{\ell }^{m}(\hat{n})<br />
</math><br />
<br />
where the coefficients <math>a_{E,\ell m}</math> and <math>a_{B,\ell m}</math> are derived from linear combinations of the <math>a_{2,\ell m}</math> , <math>a_{-2,\ell m}</math> defined implicitly in the first equation (<math>Q\pm iU</math>).<br />
<br />
[[File:test_gradient.jpg|thumb|center|400px|]]<br />
[[File:test_curl.jpg|thumb|center|400px|'''Figure 2. Error on Planck-LFI 70 GHz <math>EE</math> (top) and <math>BB</math> (bottom) spectra, in case of wrong choice of the coordinate system convention (IAU instead of COSMO).''']]<br />
<br />
The effect of the sign inversion of <math>U</math> on the polarization spectra is a non trivial mixing of <math>E</math> and <math>B</math> modes. <br />
<br />
An example of the typical error on <math>EE</math> and <math>BB</math> auto-spectra in case of a wrong choice of the polarization basis is shown in Figure 2.<br />
<br />
BE CAREFUL about the polarization convention you are using. If the IAU convention is used in computing the power spectra, the sign of the <math>U</math> component of the Planck maps must be inverted before computing <math>E</math> and <math>B</math> modes.<br />
<br />
''' Note on the convention used by the Planck Catalogue of Compact Sources (PCCS) '''<br />
For continuity with other compact sources catolgues, the Catalogue of Compact Sources provided by Planck follows the IAU convention, and the polarization angles are defined on an interval of [-90&deg;,90&deg;]. To switch to the COSMO convention, the polarization angles listed in the catalogue have to be shifted by 90&deg; and multiplied by -1.<br />
<br />
== References ==<br />
<References /><br />
<br />
</div><br />
</div><br />
<br />
<div class="toccolours mw-collapsible mw-collapsed" style="background-color: #EEE8AA;width:80%" ><br />
'''2013 Sky temperature maps'''<br />
<br />
<div class="mw-collapsible-content"><br />
<br />
'''General description'''<br />
<br />
<br />
Sky maps give the best estimate of the intensity of the signal from the sky after removal, as far as possible, of known systematic effects and of the dipole signals induced by the motion of the solar system in the CMB and of the Planck satellite in the solar system. Sky maps are provided for the nominal Planck mission and also, separately, for the first two single surveys, the third one being covered only for a small part during the nominal mission.The details of the start and end times of each are given in [[HFIpreprocessingstatics | this table]]. As a secondary product, maps with estimates of the Zodiacal light and Far-Side-Lobes contribution removed are also provided. <br />
<br />
For characterization purposes, are also provided maps covering the nominal survey but each one using only half of the available data. These are the ''ringhalf_{1|2}'' maps, which are built using the first and second half of the stable pointing part in each pointing period. These maps are used extensively to investigate the (high frequency) noise properties the maps themselves and of other products described elsewhere (see e.g., the [[HFI-Validation | data validation]] section).<br />
<br />
To help in further processing, there are also masks of the Galactic Plane and of point sources, each provided for several different depths.<br />
<br />
All sky maps are in Healpix format, with Nside of 2048 for HFI and of 1024 for LFI (note that the LFI 70 GHz has been delivered also at Nside of 2048 to be directly comparable with HFI maps), in Galactic coordinates, and Nested ordering. The signal is given in units of K<sub>cmb</sub> for 30-353 GHz, and of MJy/sr (for a constant $\nu F_\nu$ energy distribution ) for 545 and 857 GHz. Each sky map is packaged into a ''BINTABLE'' extension of a FITS file together with a hit-count map (or hit map, for short, giving the number of observation samples that are cumulated in a pixel, all detectors combined) and a variance map (determined from the half-ring maps), and additional information is given in the FITS file header. The structure of the FITS file is given in the [[#Format | FITS file structure]] section below.<br />
<br />
<br />
'''Types of maps '''<br />
<br />
; Full channel maps<br />
: Full channel maps are built using all the valid detectors of a frequency channel and cover the nominal mission. For HFI, the 143-8 and 545-3 bolometers are rejected entirely as they are seriously affected by RTS noise. The maps are displayed in the figures below. The range is the same from 30 - 143 GHz in order to show the CMB at the same level. At higher frequencies the range is increased in order to keep the Galactic Plane from invading the whole sky.<br />
<br />
<center><br />
<gallery style="padding:0 0 0 0;" perrow=3 widths=260px heights=160px> <br />
File: SkyMap30.png| '''Nominal mission, 30 GHz'''<br />
File: SkyMap44.png | '''Nominal mission, 44 GHz'''<br />
File: SkyMap70.png | '''Nominal mission, 70 GHz'''<br />
File: SkyMap100.png | '''Nominal mission, 100 GHz'''<br />
File: SkyMap143.png | '''Nominal mission, 143 GHz'''<br />
File: SkyMap217.png | '''Nominal mission, 217 GHz'''<br />
File: SkyMap353.png | '''Nominal mission, 353 GHz'''<br />
File: SkyMap545.png | '''Nominal mission, 545 GHz'''<br />
File: SkyMap857.png | '''Nominal mission, 857 GHz'''<br />
</gallery><br />
</center><br />
<br />
; Single survey maps <br />
: Single survey maps are built using all valid detectors of a frequency channel; they cover separately the different sky surveys. The surveys are defined as the times over which the satellite spin axis rotates but 180 degrees, which, due to the position of the detectors in the focal plane does not cover the full sky, but a fraction between ~80 and 90% depending on detector position.<br />
<br />
; Detector set or detector pairs maps<br />
: These are maps built from a subset of the detectors in a frequency channel, typically our of two PSB pairs (i.e., four poloarisation-sensitive bolometers with different orientation on the sky), for HFI in order to extract a single temperature map. While none of these maps are part of the first Planck data release, the concept of ''detset'' is used, and thus it is worth mentioning it here. In particular, information by detector set is available at the [[Frequency_maps_angular_power_spectra | sky power spectrum]] level and in the [[The RIMO | RIMO]].<br />
<br />
; Half-ring maps<br />
: Half-ring maps are built using only the first or the second half of the stable pointing period data. There are thus two half-ring maps per frequency channel named ''ringhalf_1'' and ''ringhalf_2'' respectively. These maps are built for characterization purposes in order to perform null tests. In particular, the difference between the two half-ring maps at a given frequency give a good estimate of the high frequency noise in the data (albeit biased low by ~0.5% for the HFI channels due to specifics of the TOI processing).<br />
<br />
; Masks<br />
: Masks are provided of the Galactic Plane and of the point sources. For the Galactic Plane, eight masks are given covering different fractions of the sky, and for the points sources two masks are given, at the 5 and 10 sigma level, for each Planck HFI frequency channel. These are generic masks, specific masks applicable to other products are delivered with the products themselves.<br />
<br />
''' Caveats and known issues'''<br />
<br />
The primary limitation of the HFI maps are<br />
* the absence of correction of the ADC non-linearities,<br />
* the far-side lobe contribution is not accounted for in the processing and in the calibration,<br />
* the dipole removal is based on the non-relativistic approximation which leaves a weak quadrupole component in the map.<br />
And thus the overall calibration accuracy is at the 0.2% level in 100-217 GHz channels<br />
<br />
The LFI 70 GHz maps at Nside=2048 should be considered as additional product, the default are the LFI maps at Nside=1024. No effective beam at Nside=2048 is provided, only at Nside=1024, for this reason the use of the effective beam with maps at Nside 2048 is discouraged.<br />
<br />
''' Map zero-level '''<br />
<br />
For the 100 to 857 GHz maps, the zero levels are set to their optimal levels for Galactic and CIB studies. A procedure for adjusting them to astrophysical values is given in the HFI Calibration paper {{PlanckPapers|planck2013-p03b}}.<br />
<br />
For the 30, 44 and 70 GHz, maps are corrected for zero level monopole by applying an offset correction, see LFI Calibration paper {{PlanckPapers|planck2013-p02b}} section 3.4 "Setting the zero levels in the maps". Note that the offset applied is indicated in the header as a comment keyword.<br />
<br />
''' The Zodiacal light and the Far-Side Lobes '''<br />
<br />
The figures below show the modeled Zodiacal light and Far Side Lobes projected onto the maps; they are simply the difference between the ''main product'' and the ''ZodiCorrected'' maps for the nominal mission. The units are given in the figures. The ''heat'' color table has been used in place of the standard Planck for clarity reasons. <br />
<center><br />
<gallery perrow=3 widths=260px heights=170px><br />
File: ZodiRes100.png | '''zodi/FSL rediduals - 100 GHz'''<br />
File: ZodiRes143.png | '''zodi/FSL rediduals - 143 GHz''' <br />
File: ZodiRes217.png | '''zodi/FSL rediduals - 217 GHz'''<br />
File: ZodiRes353.png | '''zodi/FSL rediduals - 353 GHz'''<br />
File: ZodiRes545.png | '''zodi/FSL rediduals - 545 GHz'''<br />
File: ZodiRes857.png | '''zodi/FSL rediduals - 857 GHz'''<br />
</gallery><br />
</center><br />
The effects of the FSLs are seen most clearly at the highest frequencies, as structures roughly symmetric about the center of the image, which corresponds to the location of the Galactic Centre, which is in turn the source of most of the radiation that is scattered into the FSLs.<br />
<br />
''' Artifacts near caustics of the scanning strategy '''<br />
<br />
The [[Survey scanning and performance|scanning strategy]] is such that regions around the Ecliptic poles are surveyed very deeply and compared to the average, and the transition from the nominal depth to the high depth, as shows on hit-count maps is very rapid, namely a few pixels, for a contrast of ~30. These transitions, or caustics in the maps, occur at different positions on the sky for different detectors, as the positions depend on their location in the focal plane of the instrument. As a result, when data from different detectors are combined to build a full channel map, the the weights of different detectors in the mix changes rapidly across the caustic, and given the remaining errors in the relative calibration of the detectors, a visible effect can be introduced in the maps, especially when the SNR is very high, i.e. at the highest frequencies and near bright regions like the Galactic Plane. Some examples are shown below.<br />
<br />
<center><br />
<gallery perrow=3 heights=260px widths=260pix ><br />
File: causta857.png | '''857 GHz intensity map around (272.5, -27)'''<br />
File: caustb857.png | '''857 GHz intensity map around (264.5, -37.5)'''<br />
File: caustc857.png | '''857 GHz intensity map around (98.5, 43)'''<br />
File: hita857.png | '''857 GHz hit count map around (272.5, -27)'''<br />
File: hitb857.png | '''857 GHz hit count map around (264.5, -37.5)'''<br />
File: hitc857.png | '''857 GHz hit count map around (98.5, 43)'''<br />
</gallery><br />
</center><br />
<br />
'''Production process'''<br />
<br />
<br />
Sky maps are produced by combining appropriately the data of all working detectors in a frequency channel over some period of the mission. They give the best estimate of the signal from the sky (unpolarised) after removal, as far as possible, of known systematic effects and of the dipole signals induced by the motion of the solar system in the CMB and of the Planck satellite in the solar system. In particular, they include the Zodiacal light emission (Zodi for short) and also the scattering from the far-side lobes of the beams (FSL). More on this below.<br />
<br />
''' HFI processing '''<br />
<br />
The inputs to the mapmaking are TOIs of signal that have been cleaned (as far as possible) of instrumental effects and calibrated in absorbed watts. While the processing involved is described in detail in the [[TOI processing|TOI processing]] section, we give a very brief summary here for convenience. That pipeline performs the following operations:<br />
<br />
; demodulation: this is performed around a variable level which is determined from the valid input data (a validity flag from a previous version of the processing is used for this purpose), and the data are converted to engineering units (V) using known conversion coefficients.<br />
; despiking: using the demodulated data converted to V (by the transfer function) the glitches are identified and fitted with templates. A glitch flag is produced that identifies the strongest part of the glitches, and a timeline of glitch tails is produced from the template fits, and subtracted from the demodulated timeline from step 1. Finally, the flagged ranges are replaced with data from an average over the pointing period (TBC)<br />
; dark template removal: the two dark bolometers are demodulated and despiked as above; the resulting timelines are then smoothed and used as an indicator of the overall temperature variations of the bolometer plate. Where the variations are consistent with each other, they are combined and removed from the bolometer signal timelines using appropriate coupling coefficients. The few percent of the data where they are not consistent are flagged on the timelines.<br />
; conversion to absorbed power: the timeline is converted to watts of absorbed power using the bolometer function. This includes a non-linearity correction; removal of the 4K cooler lines: the electromagnetic interference of the 4K cooler with the bolometer readout wires induces some sharp lines in the signal power spectra at frequencies of the 4K cooler's fundamental and its multiples, folded by the signal modulations. Fourier coefficients of the relevant lines are determined on a per-ring basis, and then removed from the data. The quality of the removal depends on the bolometer.<br />
; deconvolution by the time transfer function: this is done to correct for the non-instantaneous time response of the bolometers. The function itself is modeled using 4 parameters which are adjusted primarily on the planet data and also from comparisons of the northward and southward scans of the Galactic Plane. It is then removed using Fourier techniques, which has the side-effect of increasing the noise at high frequencies.<br />
; jump correction: removes some (relatively rare: 0.3 jumps per bolometer per pointing period, on average) jumps in the signal baseline. The jumps are detected characterized on smoothed TOIs, and corrected by adding a constant to part of the signal timeline. The origin of the jumps is not known.<br />
<br />
The results of this processing are a timeline of signal (in absorbed watts) and a ''valid data'' flag timeline for each of the 50 valid bolometers processed; these timelines contain the full sky signal, i.e., including the solar and orbital dipoles, the Zodiacal light, and contributions from the Far-Side lobes. The dipoles are necessary for the flux calibration and are removed at the mapmaking stage. The remaining two bolometers (143-8 and 535-3) show semi-random jumps in the signal level, typically jumping over 2-5 different ''pseudo-baseline'' levels, a behavior known as ''Random Telegraphic Signal'', so that these are commonly called the RTS bolometers. Finally, ring-level statistics of different types (mean, median, rms, kurtosis, etc.) are determined on a per-ring basis for all timelines, and a selection based on these statistics is used to discard anomalous rings, which are recorded in a ring-level flag for each valid bolometer timeline (see the [[TOI_processing#Discarded_rings| Discarded rings]] section). <br />
<br />
Throughout this processing, bright planets (Mars, Jupiter, Saturn, Uranus) and bright asteroids are masked in the timeline in order to avoid ringing effects in the processing. Since they move on the sky, the portion of the sky masked during one survey is observed during one, and no hole is left in the final map. In parallel, the planet data are processed in a similar way, but with different parameters for the despiking step, and without the final jump correction step. These results are processed separately to determine the beam shapes and the focal plane geometry.<br />
<br />
The pointing is determined starting from the AHF produced by MOC, which gives the direction and orientation of the LOS of a fiducial position in the focal plane at frequencies of 8Hz during stable pointing and 4 Hz during maneuvers (TBC for details, reference). This is interpolated to the times of data observation (ref to method), corrected for the wobble and other time-dependent offsets determined from the observed positions of a large number of sources around the sky, and finally converted to the LOS of each detector using the quaternions in the IMO (which are determined from observations of bright planets - see the [[Detector_pointing]] section). <br />
<br />
The mapmaking and calibration process is described in detail in the [[Map-making_LFI | Map-making]] section, where detailed references are found. In brief it consists of:<br />
<br />
; binning the TOI data onto ''rings'' : Healpix rings (HPRs) are used here, each ring containing the combined data of one pointing period. <br />
; flux calibration : at 100-353 GHz, the flux calibration factors are determined for each pointing period (or ring) from the solar-motion dipole, using the WMAP dipole as the reference, and after removal of the dipole signal induced by the motion of the Planck satellite in the solar system. This gain by ring is smoothed with a window of width 50 rings, which reveals an apparent variation of ~1-2% on a scale of 100s to 1000s of rings for the 100-217 GHz channels, and is applied. At 353GHz, where the solar motion dipole is weaker compared to the signal, no gain variation is detected (within the uncertainties), and a single fixed gain is applied to all rings. At 545 and 857 GHz the gain is determined from the observation of Uranus and Neptune (but not Jupiter which is too bright) and comparison to recent models made explicitly for this mission. A single gain is applied to all rings at these frequencies.<br />
; destriping : in order to remove low-frequency noise, an offset per ring is determined by minimizing the differences between HPRs at their crossings, and removed.<br />
; projection onto the map : the offset-corrected and flux-calibrated HPRs are projected onto Healpix maps, with the data of each bolometer weighted by a factor of 1/NET of that bolometer, and accounting for the slight different band transmission profiles of the bolometers in each band. <br />
<br />
These maps provide the main mission products. A second, reduced, set of maps, cleaned of the Zodiacal emission of the FSL leakage is also produced for the nominal mission and the two single surveys, but not for the half-rings (since the contribution would be the same for the two halves of each ring). For this purpose, the the Zodiacal emission and the FSL contamination, which are not fixed on the sky, are modeled separately at HPR-level, and subtracted from the signal HPR before projecting them onto the maps. <br />
<br />
Together with signal maps, hit count and variance maps are also produced. The hit maps give the (integer) number of valid TOI-level samples that contribute to the signal of each pixel. All valid samples are counted in the same way, i.e., there is no weighting factor applied. The variance maps project the white noise estimate, provided by the NETs, in the sky domain.<br />
<br />
''' LFI processing '''<br />
<br />
LFI maps were constructed with the Madam map-making code, version 3.7.4. The code is based on generalized destriping technique, where the correlated noise component is modeled as a sequence of constant offset, called baselines. A noise filter was used to constrain the baseline solution allowing the use of 1 second baselines.<br />
<br />
Radiometers were combined according to the horn-uniform weighting scheme to minimize systematics. The used weights are listed in [[Map-making LFI#Map-making|Map-making]]. The flagged samples were excluded from the analysis by setting their weights to $C_{w}^{-1}$ = 0. The galaxy region was masked out in the destriping phase, to reduce error arising from strong signal gradients. The polarization component was included in the analysis, although only the temperature maps are released. <br />
<br />
A detailed description of the map-making procedure is given in {{PlanckPapers|planck2013-p02}} and in section [[Map-making LFI#Map-making|Map-making]].<br />
<br />
'''Inputs'''<br />
<br />
<br />
''' HFI inputs '''<br />
<br />
* The cleaned TOIs of signal of each detector, together with their flags, produced by the [[TOI processing|TOI processing]] pipeline<br />
* The TOIs of pointing (quaternions), described in [[Detector_pointing]]<br />
* Bolometer-level characterization data, from the DPC's internal IMO (not distributed)<br />
* Planck orbit data used to compute and remove the earth dipole<br />
* WMAP solar dipole information used to calibrate the CMB channels<br />
* Planet models used to calibrate the Galactic channels.<br />
<br />
''' LFI inputs '''<br />
<br />
The Madam map-maker takes as an input:<br />
<br />
* The calibrated timelines (for details see [[TOI processing LFI|TOI Processing]])<br />
* The detector pointings (for details see [[Detector pointing|Detector pointing]])<br />
* The noise information in the form of three-parameter (white noise level ($\sigma$), slope, and knee frequency ($f_\mathrm{knee}$)) noise model (for details see [[The RIMO|RIMO]])<br />
<br />
'''Related products'''<br />
<br />
<br />
''' Masks '''<br />
<br />
Masks are provided of<br />
<br />
; the point sources<br />
: 15 masks are provided, three for the LFI (one mask for each frequency masking at the 4<math>\sigma</math> level) and 12 for the HFI (two masks for each frequency at the 5 and 10<math>\sigma</math> levels. For the HFI the masks can be used as they are, for the LFI they need to be downgraded to Nside=1024 except for the 70 GHz channel at Nside=2048 which does not need to be downgraded.<br />
<br />
; the Galactic Plane<br />
: 8 masks are provided giving 20, 40, 60, 70, 80, 90, 97, and 99% sky coverage in two different files, at Nside=2048. For the HFI they can be used as they are, for the LFI they need to be downgraded at Nside=1024 (note that if using the 70 GHZ at Nside=2048 no downgraded is needed)<br />
<br />
<br />
The masks are binary, in GALACTIC coordinates, and NESTED ordering. The table below give the filenames. <br />
<br />
<br />
{| class="wikitable" align="center" style="text-align:center" border="1" cellpadding="5" cellspacing="0" <br />
|+ '''FITS filenames for masks'''<br />
|-bgcolor="ffdead"<br />
! Frequency || LFI Point Source masks<br />
|-<br />
| '''30GHz''' || {{PLASingleFile|fileType=map|name=LFI_MASK_030-ps_2048_R1.00.fits|link=LFI_MASK_030-ps_2048_R1.00.fits}}<br />
|-<br />
| '''44GHz''' || {{PLASingleFile|fileType=map|name=LFI_MASK_044-ps_2048_R1.00.fits|link=LFI_MASK_044-ps_2048_R1.00.fits}}<br />
|-<br />
| '''70GHz''' || {{PLASingleFile|fileType=map|name=LFI_MASK_070-ps_2048_R1.00.fits|link=LFI_MASK_070-ps_2048_R1.00.fits}}<br />
|- bgcolor="ffdead"<br />
! colspan="2" | HFI Point Source masks<br />
|-<br />
| colspan="2" | {{PLASingleFile|fileType=map|name=HFI_Mask_PointSrc_2048_R1.10.fits|link=HFI_Mask_PointSrc_2048_R1.10.fits}}<br />
|- bgcolor="ffdead"<br />
! colspan="2" | Galactic Plane masks<br />
|-<br />
| colspan="2" | {{PLASingleFile|fileType=map|name=HFI_Mask_GalPlane_2048_R1.10.fits|link=HFI_Mask_GalPlane_2048_R1.10.fits}} <br />
|}<br />
<br />
<br />
The masks are shows below in a single figure. While this is quite clear for the Galactic Plane masks, it is less so for the point source masks, but it does give a clear perspective on how the latter are distributed over the sky.<br />
<br />
<center><br />
<gallery perrow=2 widths=300px heights=185px ><br />
File: HFI_GalPlaneMask.png | '''Galactic Plane masks'''<br />
File: HFI_PointSrcMask.png | '''PointSource masks'''<br />
</gallery><br />
</center><br />
<br />
''' File names '''<br />
<br />
<br />
The FITS filenames are of the form ''{H|L}FI_SkyMap_fff_nnnn_R1.nn_{coverage}_{type}.fits'', where ''fff'' are three digits to indicate the Planck frequency band, and ''nnnn'' is the Healpix Nside of the map, ''coverage'' indicates which part of the mission is covered, and the optional ''type'' indicates the subset of input data used. A full list of products, with links to them in the Archive, is given in the tables below.<br />
<br />
For the benefit of users who are only looking for the frequency maps with no additional information, we also provide a file combining the 9 frequency maps as separate columns in a single extension. The 9 columns in this file contain the intensity maps ONLY and no other information (hit maps and variance maps) is provided.<br />
<br />
{| class="wikitable" align="center" style="text-align:center" border="1" cellpadding="5" cellspacing="0" width=500px<br />
|+ '''FITS filenames'''<br />
|- bgcolor="ffdead"<br />
! Frequency || Full channel maps<br />
|-<br />
| '''30GHz''' || {{PLASingleFile|fileType=map|name=LFI_SkyMap_030_1024_R1.10_nominal.fits|link=LFI_SkyMap_030_1024_R1.10_nominal.fits}}<br />
|-<br />
| '''44GHz''' || {{PLASingleFile|fileType=map|name=LFI_SkyMap_044_1024_R1.10_nominal.fits|link=LFI_SkyMap_044_1024_R1.10_nominal.fits}}<br />
|-<br />
| '''70GHz''' || {{PLASingleFile|fileType=map|name=LFI_SkyMap_070_1024_R1.10_nominal.fits|link=LFI_SkyMap_070_1024_R1.10_nominal.fits}}<br />
|-<br />
| '''70GHz''' || {{PLASingleFile|fileType=map|name=LFI_SkyMap_070_2048_R1.10_nominal.fits|link=LFI_SkyMap_070_2048_R1.10_nominal.fits}}<br />
|-<br />
| '''100GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_100_2048_R1.10_nominal.fits|link=HFI_SkyMap_100_2048_R1.10_nominal.fits}}<br />
|-<br />
| '''143GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_143_2048_R1.10_nominal.fits|link=HFI_SkyMap_143_2048_R1.10_nominal.fits}}<br />
|-<br />
| '''217GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_217_2048_R1.10_nominal.fits|link=HFI_SkyMap_217_2048_R1.10_nominal.fits}}<br />
|-<br />
| '''353GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_353_2048_R1.10_nominal.fits|link=HFI_SkyMap_353_2048_R1.10_nominal.fits}}<br />
|-<br />
| '''545GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_545_2048_R1.10_nominal.fits|link=HFI_SkyMap_545_2048_R1.10_nominal.fits}}<br />
|-<br />
| '''857GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_857_2048_R1.10_nominal.fits|link=HFI_SkyMap_857_2048_R1.10_nominal.fits}}<br />
|- bgcolor="ffdead"<br />
! Frequency || Full channel, Zodi-corrected maps<br />
|-<br />
| '''100GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_100_2048_R1.10_nominal_ZodiCorrected.fits|link=HFI_SkyMap_100_2048_R1.10_nominal_ZodiCorrected.fits}} <br />
|-<br />
| '''143GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_143_2048_R1.10_nominal_ZodiCorrected.fits|link=HFI_SkyMap_143_2048_R1.10_nominal_ZodiCorrected.fits}}<br />
|-<br />
| '''217GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_217_2048_R1.10_nominal_ZodiCorrected.fits|link=HFI_SkyMap_217_2048_R1.10_nominal_ZodiCorrected.fits}}<br />
|-<br />
| '''353GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_353_2048_R1.10_nominal_ZodiCorrected.fits|link=HFI_SkyMap_353_2048_R1.10_nominal_ZodiCorrected.fits}}<br />
|-<br />
| '''545GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_545_2048_R1.10_nominal_ZodiCorrected.fits|link=HFI_SkyMap_545_2048_R1.10_nominal_ZodiCorrected.fits}}<br />
|-<br />
| '''857GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_857_2048_R1.10_nominal_ZodiCorrected.fits|link=HFI_SkyMap_857_2048_R1.10_nominal_ZodiCorrected.fits}}<br />
|- bgcolor="ffdead"<br />
! Frequency || Combined frequency maps<br />
|-<br />
| '''All''' || {{PLASingleFile|fileType=file|name=COM_MapSet_I-allFreqs_R1.10_nominal.fits|link=COM_MapSet_I-allFreqs_R1.10_nominal.fits}} <br />
|}<br />
<br />
<br />
{| class="wikitable" align="center" style="text-align:center" border="1" cellpadding="5" cellspacing="0" width=850px<br />
|+ '''FITS filenames'''<br />
|- bgcolor="ffdead"<br />
! Frequency || Survey 1 maps || Survey 2 maps<br />
|-<br />
| '''30GHz''' || {{PLASingleFile|fileType=map|name=LFI_SkyMap_030_1024_R1.10_survey_1.fits|link=LFI_SkyMap_030_1024_R1.10_survey_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=LFI_SkyMap_030_1024_R1.10_survey_2.fits|link=LFI_SkyMap_030_1024_R1.10_survey_2.fits}}<br />
|-<br />
| '''44GHz''' || {{PLASingleFile|fileType=map|name=LFI_SkyMap_044_1024_R1.10_survey_1.fits|link=LFI_SkyMap_044_1024_R1.10_survey_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=LFI_SkyMap_044_1024_R1.10_survey_2.fits|link=LFI_SkyMap_044_1024_R1.10_survey_2.fits}}<br />
|-<br />
| '''70GHz''' || {{PLASingleFile|fileType=map|name=LFI_SkyMap_070_1024_R1.10_survey_1.fits|link=LFI_SkyMap_070_1024_R1.10_survey_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=LFI_SkyMap_070_1024_R1.10_survey_2.fits|link=LFI_SkyMap_070_1024_R1.10_survey_2.fits}}<br />
|-<br />
| '''70GHz''' || {{PLASingleFile|fileType=map|name=LFI_SkyMap_070_2048_R1.10_survey_1.fits|link=LFI_SkyMap_070_2048_R1.10_survey_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=LFI_SkyMap_070_2048_R1.10_survey_2.fits|link=LFI_SkyMap_070_2048_R1.10_survey_2.fits}}<br />
|-<br />
| '''100GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_100_2048_R1.10_survey_1.fits|link=HFI_SkyMap_100_2048_R1.10_survey_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_100_2048_R1.10_survey_2.fits|link=HFI_SkyMap_100_2048_R1.10_survey_2.fits}}<br />
|-<br />
| '''143GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_143_2048_R1.10_survey_1.fits|link=HFI_SkyMap_143_2048_R1.10_survey_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_143_2048_R1.10_survey_2.fits|link=HFI_SkyMap_143_2048_R1.10_survey_2.fits}}<br />
|-<br />
| '''217GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_217_2048_R1.10_survey_1.fits|link=HFI_SkyMap_217_2048_R1.10_survey_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_217_2048_R1.10_survey_2.fits|link=HFI_SkyMap_217_2048_R1.10_survey_2.fits}}<br />
|-<br />
| '''353GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_353_2048_R1.10_survey_1.fits|link=HFI_SkyMap_353_2048_R1.10_survey_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_353_2048_R1.10_survey_2.fits|link=HFI_SkyMap_353_2048_R1.10_survey_2.fits}}<br />
|-<br />
| '''545GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_545_2048_R1.10_survey_1.fits|link=HFI_SkyMap_545_2048_R1.10_survey_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_545_2048_R1.10_survey_2.fits|link=HFI_SkyMap_545_2048_R1.10_survey_2.fits}}<br />
|-<br />
| '''857GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_857_2048_R1.10_survey_1.fits|link=HFI_SkyMap_857_2048_R1.10_survey_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_857_2048_R1.10_survey_2.fits|link=HFI_SkyMap_857_2048_R1.10_survey_2.fits}}<br />
|- bgcolor="ffdead"<br />
! Frequency || Survey 1 Zodi-corrected maps || Survey 2 Zodi-corrected maps<br />
|-<br />
| '''100GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_100_2048_R1.10_survey_1_ZodiCorrected.fits|link=HFI_SkyMap_100_2048_R1.10_survey_1_ZodiCorrected.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_100_2048_R1.10_survey_2_ZodiCorrected.fits|link=HFI_SkyMap_100_2048_R1.10_survey_2_ZodiCorrected.fits}}<br />
|-<br />
| '''143GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_143_2048_R1.10_survey_1_ZodiCorrected.fits|link=HFI_SkyMap_143_2048_R1.10_survey_1_ZodiCorrected.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_143_2048_R1.10_survey_2_ZodiCorrected.fits|link=HFI_SkyMap_143_2048_R1.10_survey_2_ZodiCorrected.fits}}<br />
|-<br />
| '''217GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_217_2048_R1.10_survey_1_ZodiCorrected.fits|link=HFI_SkyMap_217_2048_R1.10_survey_1_ZodiCorrected.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_217_2048_R1.10_survey_2_ZodiCorrected.fits|link=HFI_SkyMap_217_2048_R1.10_survey_2_ZodiCorrected.fits}}<br />
|-<br />
| '''353GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_353_2048_R1.10_survey_1_ZodiCorrected.fits|link=HFI_SkyMap_353_2048_R1.10_survey_1_ZodiCorrected.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_353_2048_R1.10_survey_2_ZodiCorrected.fits|link=HFI_SkyMap_353_2048_R1.10_survey_2_ZodiCorrected.fits}}<br />
|-<br />
| '''545GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_545_2048_R1.10_survey_1_ZodiCorrected.fits|link=HFI_SkyMap_545_2048_R1.10_survey_1_ZodiCorrected.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_545_2048_R1.10_survey_2_ZodiCorrected.fits|link=HFI_SkyMap_545_2048_R1.10_survey_2_ZodiCorrected.fits}}<br />
|-<br />
| '''857GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_857_2048_R1.10_survey_1_ZodiCorrected.fits|link=HFI_SkyMap_857_2048_R1.10_survey_1_ZodiCorrected.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_857_2048_R1.10_survey_2_ZodiCorrected.fits|link=HFI_SkyMap_857_2048_R1.10_survey_2_ZodiCorrected.fits}}<br />
|- bgcolor="ffdead"<br />
! Frequency || Half-ring 1 maps ||Half-ring 2 maps<br />
|-<br />
| '''30GHz''' || {{PLASingleFile|fileType=map|name=LFI_SkyMap_030_1024_R1.10_nominal_ringhalf_1.fits|link=LFI_SkyMap_030_1024_R1.10_nominal_ringhalf_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=LFI_SkyMap_030_1024_R1.10_nominal_ringhalf_2.fits|link=LFI_SkyMap_030_1024_R1.10_nominal_ringhalf_2.fits}}<br />
|-<br />
| '''44GHz''' || {{PLASingleFile|fileType=map|name=LFI_SkyMap_044_1024_R1.10_nominal_ringhalf_1.fits|link=LFI_SkyMap_044_1024_R1.10_nominal_ringhalf_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=LFI_SkyMap_044_1024_R1.10_nominal_ringhalf_2.fits|link=LFI_SkyMap_044_1024_R1.10_nominal_ringhalf_2.fits}}<br />
|-<br />
| '''70GHz''' || {{PLASingleFile|fileType=map|name=LFI_SkyMap_070_1024_R1.10_nominal_ringhalf_1.fits|link=LFI_SkyMap_070_1024_R1.10_nominal_ringhalf_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=LFI_SkyMap_070_1024_R1.10_nominal_ringhalf_2.fits|link=LFI_SkyMap_070_1024_R1.10_nominal_ringhalf_2.fits}}<br />
|-<br />
| '''70GHz''' || {{PLASingleFile|fileType=map|name=LFI_SkyMap_070_2048_R1.10_nominal_ringhalf_1.fits|link=LFI_SkyMap_070_2048_R1.10_nominal_ringhalf_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=LFI_SkyMap_070_2048_R1.10_nominal_ringhalf_2.fits|link=LFI_SkyMap_070_2048_R1.10_nominal_ringhalf_2.fits}}<br />
|-<br />
| '''100GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_100_2048_R1.10_nominal_ringhalf_1.fits|link=HFI_SkyMap_100_2048_R1.10_nominal_ringhalf_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_100_2048_R1.10_nominal_ringhalf_2.fits|link=HFI_SkyMap_100_2048_R1.10_nominal_ringhalf_2.fits}}<br />
|-<br />
| '''143GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_143_2048_R1.10_nominal_ringhalf_1.fits|link=HFI_SkyMap_143_2048_R1.10_nominal_ringhalf_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_143_2048_R1.10_nominal_ringhalf_2.fits|link=HFI_SkyMap_143_2048_R1.10_nominal_ringhalf_2.fits}}<br />
|-<br />
| '''217GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_217_2048_R1.10_nominal_ringhalf_1.fits|link=HFI_SkyMap_217_2048_R1.10_nominal_ringhalf_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_217_2048_R1.10_nominal_ringhalf_2.fits|link=HFI_SkyMap_217_2048_R1.10_nominal_ringhalf_2.fits}}<br />
|-<br />
| '''353GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_353_2048_R1.10_nominal_ringhalf_1.fits|link=HFI_SkyMap_353_2048_R1.10_nominal_ringhalf_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_353_2048_R1.10_nominal_ringhalf_2.fits|link=HFI_SkyMap_353_2048_R1.10_nominal_ringhalf_2.fits}}<br />
|-<br />
| '''545GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_545_2048_R1.10_nominal_ringhalf_1.fits|link=HFI_SkyMap_545_2048_R1.10_nominal_ringhalf_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_545_2048_R1.10_nominal_ringhalf_2.fits|link=HFI_SkyMap_545_2048_R1.10_nominal_ringhalf_2.fits}}<br />
|-<br />
| '''857GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_857_2048_R1.10_nominal_ringhalf_1.fits|link=HFI_SkyMap_857_2048_R1.10_nominal_ringhalf_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_857_2048_R1.10_nominal_ringhalf_2.fits|link=HFI_SkyMap_857_2048_R1.10_nominal_ringhalf_2.fits}}<br />
|}<br />
<br />
''' FITS file structure '''<br />
<br />
<br />
[[File:FITS_FreqMap.png | 500px | right | thumb | '''FITS file structure''']]<br />
<br />
The FITS files for the sky maps contain a minimal primary header with no data, and a ''BINTABLE'' extension (EXTENSION 1, EXTNAME = ''FREQ-MAP'') containing the data. The structure is shows schematically in the figure at right. <br />
<br />
The ''FREQ-MAP'' extension contains is a 3-column table that contain the signal, hit-count and variance maps, all in Healpix format, in columns 1, 2, and 3, respectively. The number of rows is 50331648 for HFI and LFI 70 GHz at Nside=2048 and 12582912 for LFI maps at Nside=1024 (N.B: Npix = 12 Nside^2). The three columns are ''I_STOKES'' for the intensity (or temperature) signal, ''HIT'' for the hit-count and ''II_COV'' for the variance. The exact order of the columns in the figure is indicative only, and the details can be found in the keywords. <br />
<br />
Keywords indicate the coordinate system (GALACTIC), the Healpix ordering scheme (NESTED), the units (K_cmb or MJy/sr) of each column, and of course the frequency channel (FREQ). The COMMENT fields give a one-line summary of the product, and some other information useful for traceability within the DPCs. The original filename is also given in the ''FILENAME'' keyword as are the datasum and the md5 checksum for the extension. The ''BAD_DATA'' keyword gives the value used by Healpix to indicate pixels for which no signal is present (these will also have a hit-count value of 0). The COMMENT fields give further information including some traceability data for the DPC's. The main parameters are summarised below:<br />
<br />
<br />
{| border="1" cellpadding="3" cellspacing="0" align="center" style="text-align:left" width=800px<br />
|+ '''Sky map file data structure'''<br />
|- bgcolor="ffdead" <br />
!colspan="4" | 1. EXTNAME = 'FREQ-MAP' : Data columns<br />
|- bgcolor="ffdead" <br />
! Column Name || Data Type || Units || Description<br />
|-<br />
|I_STOKES || Real*4 || K_cmb or MJy/sr || The signal map<br />
|-<br />
|HITS || Int*4 || none || The hit-count map<br />
|-<br />
|II_COV || Real*4 || K_cmb<sup>2</sup> or (MJy/sr)<sup>2</sup> || The variance map<br />
|- bgcolor="ffdead" <br />
! Keyword || Data Type || Value || Description<br />
|-<br />
|PIXTYPE || string || HEALPIX ||<br />
|-<br />
|COORDSYS || string || GALACTIC ||Coordinate system <br />
|-<br />
|ORDERING || string || NESTED || Healpix ordering<br />
|-<br />
|NSIDE || Int || 1024 or 2048 || Healpix Nside <br />
|-<br />
|FIRSTPIX || Int*4 || 0 || First pixel number<br />
|-<br />
|LASTPIX || Int*4 || 12582911 or 50331647 || Last pixel number<br />
|-<br />
|FREQ || string || nnn || The frequency channel <br />
|}<br />
<br />
<br />
The same structure applies to all ''SkyMap'' products, independent of whether they are full channel, survey of half-ring. The distinction between the types of maps is present in the FITS filename (and in the traceability comment fields).<br />
<br />
''' References'''<br />
<br />
<References /><br />
<br />
<br />
</div><br />
</div><br />
<br />
<br />
<br />
[[Category:Mission products|002]]</div>Azaccheihttps://wiki.cosmos.esa.int/planck-legacy-archive/index.php?title=Frequency_maps&diff=14108Frequency maps2018-07-06T13:32:53Z<p>Azacchei: /* Full-mission, full-channel maps (7 HFI, 4 LFI) */</p>
<hr />
<div>{{DISPLAYTITLE:Frequency maps in Temperature and Polarization}}<br />
==General description==<br />
<br />
Sky maps give the best estimate of the intensity and polarization (Stokes <i>Q</i> and <i>U</i> components), if available, of the signal from the sky after removal, as far as possible, of known systematic effects (mostly instrumental, but including also the solar and Earth-motion dipoles, Galactic stray light, and the zodiacal light). The Planck Collaboration has made three releases of maps, in 2013, 2015 and 2018. This section describes the 2018 release. For descriptions of the other two releases, please go to 2013, and 2015.<br />
<br />
In the 2013, 2015 and 2018 releases, sky maps are provided for the full Planck mission using all valid detectors in each frequency channel, and also for various subsets obtained by splitting the mission into various time ranges or into subsets of the detectors in a given channel, or by considering only odd or even pointing periods. These products are especially interesting for characterization purposes (see also the [[HFI-Validation | data validation]] section), though some are also useful for the study of source variability. The details of the start and end of the time ranges are given in the table below. <br />
<br />
For this (2018) release, HFI is providing a more limited subset of maps that include the full channel maps, the half-mission and the odd-even ring splits. Also, note that for the 353 GHz band, both full channel and PSBs only maps are provided, and that by default it is the PBS-only maps that are served.<br />
<br />
<br />
{| border="1" cellpadding="3" cellspacing="0" align="center" style="text-align:left" width=800px<br />
|+ '''Ranges for mission and surveys'''<br />
|- bgcolor="ffdead" <br />
! Range || ODs || HFI rings || pointing-IDs || Comment<br />
|-<br />
|Nominal mission || 91 - 563 || 240 - 14723 || 00004200 - 03180200 ||<br />
|-<br />
|Full mission || 91 - 974 || 240 - 27005 || 00004200 - 05322620 || For HFI<br />
|-<br />
|Full mission || 91 - 1543 || n/a || 00004200 - 06511160 || For LFI<br />
|-<br />
|Survey 1 || 91 - 270 || 240 - 5720 || 00004200 - 01059820 ||<br />
|-<br />
|Survey 2 || 270 - 456 || 5721 - 11194 || 01059830 - 02114520 ||<br />
|-<br />
|Survey 3 || 456 - 636 || 11195 - 16691 || 02114530 - 03193660 ||<br />
|-<br />
|Survey 4 || 636 - 807 || 16692 - 21720 || 03193670 - 04243900 ||<br />
|-<br />
|Survey 5 || 807 - 974 || 21721 - 26050 || 05267180 - 05322590 || End of mission for HFI<br />
|-<br />
|Survey 5 || 807 - 993 || n/a || 05267180 - 06344800 || End of survey for LFI<br />
|-<br />
|Survey 6 || 993 - 1177 || n/a || 06344810 - 06398120 || LFI only <br />
|-<br />
|Survey 7 || 1177 - 1358 || n/a || 06398130 - 06456410 || LFI only <br />
|-<br />
|Survey 8 || 1358 - 1543 || n/a || 06456420 - 06511160 || LFI only <br />
|-<br />
|HFI mission-half-1 || 91 - 531 || 240 - 13471 || 00004200 - 03155580 ||<br />
|-<br />
|HFI mission-half-2 || 531 - 974 || 13472 - 27005 || 03155590 - 05322590 ||<br />
|-<br />
|LFI Year 1 || 91 - 456 || n/a || 00004200 - 02114520 ||<br />
|-<br />
|LFI Year 2 || 456 - 807 || n/a || 02114530 - 04243900 ||<br />
|-<br />
|LFI Year 3 || 807 - 1177 || n/a || 05267180 - 06398120 ||<br />
|-<br />
|LFI Year 4 || 1177 - 1543 || n/a || 06398130 - 06511160 ||<br />
|-<br />
|}<br />
<br />
To help in further processing, there are also masks of the Galactic plane and of point sources, each provided for several different depths. <br />
<br />
All sky maps are in HEALPix format, with <i>N</i><sub>side</sub>=1024 (for LFI 30, 44, and 70GHz) and 2048 (for LFI 70GHz and HFI), in Galactic coordinates, and with nested ordering. <br />
<br />
'''WARNING''': The HEALPix convention for polarization is <b>not</b> the same as the IAU convention ([[#Polarization convention used in the Planck project|Section 8 on this page]]).<br />
<br />
The signal is given in units of K<sub>CMB</sub> for 30 to 353 GHz, and of MJy.sr<sup>-1</sup> (for a constant &nu;<i>I</i><sub>&nu;</sub> energy distribution) for 545 and 857 GHz. For each frequency channel, the intensity and polarization maps are packaged into a "BINTABLE" extension of a FITS file together with a hit-counts map (or "hits map", for short, giving the number of observation samples that are accumulated in a pixel, all detectors combined) and with the variance and covariance maps. Additional information is given in the FITS file header. The structure of the FITS file is given in the [[#FITS_file_structure | FITS file structure]] section below.<br />
<br />
==Production process==<br />
<br />
Sky maps are produced by appropriately combining the data from all working detectors in a frequency channel over some period of the mission. They give the best estimate of the signal from the sky (unpolarized) after removal, as far as possible, of known systematic effects and of the dipole signals induced by the motion of the solar system in the CMB and of the Planck satellite in the solar system. In particular, they include the zodiacal light emission ("zodi" for short) and also the scattering from the far sidelobes of the beams (FSL). More on this below.<br />
<br />
=== HFI processing ===<br />
<br />
The mapmaking and calibration process is described in detail in the [[Map-making_LFI | mapmaking]] section and in the {{PlanckPapers|planck2016-XLVI}} paper, where detailed references can be found. In brief, the timelines are cleaned and calibrated and converted into HealPix rings (HPRs), then ''SRoll'' is applied to destripe them in polarised space (removal of very low frequency noise by minimising differences at ring crossing points), to remove knows systematic effects (including the flux calibration), and to project them onto a HealPix map.<br />
<br />
The processing yields maps of the signal, hit counts and auto- and cross-variance maps for the 6 full channel and for a pseudo-channel built from the 353 PSBs only. For each channel HFI provides <br />
* a map for the full mission<br />
* two maps for each half-mission<br />
* two maps for built from odd or even rings only<br />
<br />
for a total of 35 maps. <br />
<br />
==== PR3 HFI products ====<br />
<br />
===== Healpix Pixel Rings (HPRs) =====<br />
''SRoll'' main products are the HFI frequency maps. Nevertheless, we also make available the Healpix Pixel Rings (HPRs) of those maps, ie. the data before projection. See [[Healpix_Rings_HFI| description of those files]].<br />
<br />
===== Frequency maps =====<br />
<br />
The 35 HFI frequency maps of the PR3 Legacy Release are the followings:<br />
<br />
{| border="1" cellpadding="3" cellspacing="0" align="center" style="text-align:left" width=800px<br />
|+ '''PR3 HFI frequency maps'''<br />
|- bgcolor="ffdead"<br />
!<br />
!100 GHz<br />
!143 GHz<br />
!217 GHz<br />
!353 GHz<br />
!353_PSB GHz<br />
!545 GHz<br />
!857 GHz<br />
|-<br />
| Full mission<br />
| I, Q, U<br />
| I, Q, U<br />
| I, Q, U<br />
| I, Q, U<br />
| I, Q, U<br />
| I<br />
| I<br />
|-<br />
| Half mission 1<br />
| I, Q, U<br />
| I, Q, U<br />
| I, Q, U<br />
| I, Q, U<br />
| I, Q, U<br />
| I<br />
| I<br />
|-<br />
| Half mission 2<br />
| I, Q, U<br />
| I, Q, U<br />
| I, Q, U<br />
| I, Q, U<br />
| I, Q, U<br />
| I<br />
| I<br />
|-<br />
| Odd rings<br />
| I, Q, U<br />
| I, Q, U<br />
| I, Q, U<br />
| I, Q, U<br />
| I, Q, U<br />
| I<br />
| I<br />
|-<br />
| Even rings<br />
| I, Q, U<br />
| I, Q, U<br />
| I, Q, U<br />
| I, Q, U<br />
| I, Q, U<br />
| I<br />
| I<br />
|}<br />
<br />
See [[Frequency_maps|description of those files]]. These maps are available on the [[https://www.cosmos.esa.int/web/planck/pla| Planck Legacy Archive]].<br />
<br />
<br />
=== LFI processing ===<br />
LFI maps were constructed with the MADAM mapmaking code, version 3.7.4. The code is based on a generalized destriping technique, where the correlated noise component is modelled as a sequence of constant offsets, called "baselines". A noise filter was used to constrain the baseline solution, allowing the use of 0.25-s and 1-s baselines for the 30 and 44GHz, and 70 GHz channels, respectively. See section 6 of {{PlanckPapers|planck2016-l02}}.<br />
<br />
<br />
Radiometers were combined according to the horn-uniform weighting scheme to minimize systematics. The flagged samples were excluded from the analysis by setting their weights to <i>C</i><sub>w</sub><sup>-1</sup> = 0. The Galaxy region was masked out in the destriping phase, to reduce errors arising from strong signal gradients. The polarization component was included in the analysis. <br />
<br />
; Dipole and Far Side Lobe correction: Input timelines are cleaned by the 4&pi;-convolved dipole and Galactic stray light, obtained as a convolution of the 4&pi; in-band far sidelobes and Galactic simulations, as explained in {{PlanckPapers|planck2016-l02}}. <br />
<br />
Scaling of the maps due to beam effects is taken into account in the LFI's beam functions (as provided in [[The_RIMO|the RIMO]]) which should be used for analysis of diffuse components.<br />
<br />
; Bandpass leakage correction :LFI high-resolution maps have been reseleased corrected for bandpass leakage or uncorrected. Further details about the procedure used to generate the bandpass correction maps can be found in section 7 of {{PlanckPapers|planck2016-l02}}.<br />
<br />
; Map zero-level : The 30, 44 and 70 GHz, maps are corrected for a zero-level monopole by applying an offset correction (see the LFI Calibration paper, {{PlanckPapers|planck2014-a06}}). Note that the offset applied is indicated in the header as a comment keyword.<br />
<br />
A detailed description of the mapmaking procedure is given in {{PlanckPapers|planck2013-p02}}, {{PlanckPapers|planck2014-a03}}, {{PlanckPapers|planck2014-a07}} and in the [[Map-making LFI#Map-making|Mapmaking]] section here, in {{PlanckPapers|planck2016-l02}} only a summary is reported.<br />
<br />
==Types of map ==<br />
<br />
=== Full-mission, full-channel maps (7 HFI, 4 LFI)===<br />
<br />
Full channel maps are built using all the valid detectors of a frequency channel and cover either the full or the nominal mission. For HFI, the 143-8 and 545-3 bolometers are rejected entirely, since they are seriously affected by RTS noise. HFI provides the Q and U components for the 100, 143, 217 and 353 GHz channels only. LFI provides the <i>I</i>, <i>Q</i>, and <i>U</i> maps for all the channels. Note that the HFI and LFI <i>Q</i> and <i>U</i> maps are corrected for bandpass leakage, version without correction for LFi is also provided. The <i>I</i>, <i>Q</i>, and <i>U</i> maps are displayed in the figures below. The colour range here is set using a histogram equalization scheme (from HEALPix) that is useful for these non-Gaussian data fields. For visualization purposes, the <i>Q</i> and <i>U</i> maps shown here have been smoothed with a 1&deg; Gaussian kernel, otherwise they look like noise to the naked eye. The 70 GHz full map is also available at <i>N</i><sub>side</sub>=2048.<br />
<br />
The high dynamic range colour scheme of the Planck maps is described [https://wiki.cosmos.esa.int/planck-legacy-archive/index.php/Planck_high_dynamic_range_colour_palette here].<br />
<br />
<center><br />
<gallery style="padding:0 0 0 0;" perrow=3 widths=260px heights=160px> <br />
File: LFI_030GHz_dx12_I.png| '''Full mission <i>I</i>, 30 GHz.'''<br />
File: LFI_044GHz_dx12_I.png| '''Full mission <i>I</i>, 44 GHz.'''<br />
File: LFI_070GHz_dx12_I.png| '''Full mission <i>I</i>, 70 GHz.'''<br />
File: SkyMap100e.png| '''Full mission <i>I</i>, 100 GHz.'''<br />
File: SkyMap143e.png| '''Full mission <i>I</i>, 143 GHz.'''<br />
File: SkyMap217e.png| '''Full mission <i>I</i>, 217 GHz.'''<br />
File: SkyMap353e.png| '''Full mission <i>I</i>, 353 GHz.'''<br />
File: SkyMap545e.png| '''Full mission <i>I</i>, 545 GHz.'''<br />
File: SkyMap857e.png| '''Full mission <i>I</i>, 857 GHz.'''<br />
</gallery><br />
</center><br />
<br><br />
<center><br />
<gallery style="padding:0 0 0 0;" perrow=3 widths=260px heights=160px> <br />
File: LFI_030GHz_dx12_Q.png| '''Full mission <i>Q</i>, 30 GHz.'''<br />
File: LFI_044GHz_dx12_Q.png | '''Full mission <i>Q</i>, 44 GHz.'''<br />
File: LFI_070GHz_dx12_Q.png | '''Full mission <i>Q</i>, 70 GHz.'''<br />
File: HFI_Skymap_100_full_bplcorrected_sm1deg_Qb.png | '''Full mission <i>Q</i>, 100 GHz.'''<br />
File: HFI_Skymap_143_full_bplcorrected_sm1deg_Qb.png | '''Full mission <i>Q</i>, 143 GHz.'''<br />
File: HFI_Skymap_217_full_bplcorrected_sm1deg_Qb.png | '''Full mission <i>Q</i>, 217 GHz.'''<br />
File: HFI_Skymap_353_full_bplcorrected_sm1deg_Qb.png | '''Full mission <i>Q</i>, 353 GHz.'''<br />
</gallery><br />
</center><br />
<br><br />
<center><br />
<gallery style="padding:0 0 0 0;" perrow=3 widths=260px heights=160px> <br />
File: LFI_030GHz_dx12_U.png| '''Full mission <i>U</i>, 30 GHz.'''<br />
File: LFI_044GHz_dx12_U.png | '''Full mission <i>U</i>, 44 GHz.'''<br />
File: LFI_070GHz_dx12_U.png | '''Full mission <i>U</i>, 70 GHz.'''<br />
File: HFI_Skymap_100_full_bplcorrected_sm1deg_Ub.png | '''Full mission <i>U</i>, 100 GHz.'''<br />
File: HFI_Skymap_143_full_bplcorrected_sm1deg_Ub.png | '''Full mission <i>U</i>, 143 GHz.'''<br />
File: HFI_Skymap_217_full_bplcorrected_sm1deg_Ub.png | '''Full mission <i>U</i>, 217 GHz.'''<br />
File: HFI_Skymap_353_full_bplcorrected_sm1deg_Ub.png | '''Full mission <i>U</i>, 353 GHz.'''<br />
</gallery><br />
<br />
</center><br />
<br />
=== Full mission light maps, full channel maps (7 HFI, 7 LFI)===<br />
<br />
These maps are based on the Full mission maps but contain fewer columns, IQU from 30 to 353 GHz, and I only at 545 and 857 GHz. These maps have been produced to reduce the transfer time of the most downloaded frequency full mission maps.<br />
<br />
=== Single-survey, full-channel maps (35 LFI)===<br />
<br />
Single-survey maps are built using all valid detectors of a frequency channel; they separately cover the different sky surveys. The surveys are defined as the times over which the satellite spin axis rotates by 180&deg;, which, due to the position of the detectors in the focal plane does not cover the full sky, but a fraction between about 80% and 90%, depending on detector position. During adjacent surveys the sky is scanned in opposite directions (more precisely it is the ecliptic equator that is scanned in opposite directions). While these are useful to investigate variable sources, they are also used to study the systematics of the time-response of the detectors as they scan bright sources, like the Galactic Plane, in different directions during different survey. Note that the HFI and LFI missions cover five and eight surveys, respectively, and in the case of HFI the last survey in incomplete.<br />
The 70 GHz survey maps are available also at <i>N</i><sub>side</sub>=2048. Note that LFI provides a special survey-map combination used in the low-&#8467; analysis; this maps, available at the three LFI frequencies, 30, 44, and 70 GHz, was built using the combination of Surveys 1, 3, 5, 6, 7, and 8.<br />
<br />
=== Year maps, full-channel maps (16 LFI)===<br />
<br />
These maps are built using the data of Surveys 1+2, Surveys 3+4, and so forth. They are used to study long-term systematic effects. The 70 GHz years maps are available also at <i>N</i><sub>side</sub>=2048.<br />
<br />
===Half-mission maps, full-channel maps (14 HFI, 12 LFI)===<br />
<br />
For HFI, the half mission is defined after eliminating those rings that are discarded for all bolometers, many of which occurred during the 5th survey when the "End-of-Life" tests were performed. The remaining rings are divided in half to define the two halves of the mission. This exercise is done for the full mission only.<br />
<br />
For LFI, instead of the half-mission maps, the following year combinations have been created: Year 1+2, Year 1+3, Year 2+4, Year 3+4,<br />
<br />
===Full mission, single-detector maps (22 LFI)===<br />
<br />
For LFI, all the 22 Radiometers maps are available, and (obviously) only in Stokes <i>I</i>.<br />
<br />
===Full-mission, detector-set or detector-pairs maps (8 LFI)===<br />
<br />
The objective here is to build independent temperature (<i>I</i>) and polarization (<i>Q</i> and <i>U</i>) maps using the two pairs of polarization-sensitive detectors of each channel where they are available, i.e., for the 44-353 GHz channels. The table below indicates which detectors were used to build each detector set (detset).<br />
<br />
{| border="1" cellpadding="3" cellspacing="0" align="center" style="text-align:left" width=600px<br />
|+ '''Definition of LFI detector pairs'''<br />
|- bgcolor="ffdead" <br />
!Frequency || Horn pair || Comment <br />
|-<br />
|44 GHz || 24 || This map is only in temperature<br />
|-<br />
|44 GHz || 25 and 26 || <br />
|-<br />
|70 GHz || 18 and 23 || Available also at <i>N</i><sub>side</sub>=2048<br />
|-<br />
|70 GHz || 19 and 22 || Available also at <i>N</i><sub>side</sub>=2048<br />
|-<br />
|70 GHz || 20 and 21 || Available also at <i>N</i><sub>side</sub>=2048<br />
|}<br />
<br />
===Half-ring maps (62 LFI)===<br />
<br />
These maps are similar to the ones described above, but are built using only the first or the second halves of each ring (or pointing period). The HFI provides half-ring maps for the full mission only, as well as for the full channel, the detsets, and the single bolometers. The LFI provides half-ring maps for the full mission in each channel (70 GHz also at <i>N</i><sub>side</sub>=2048), for the full-mission radiometers, and for the full-mission horn pairs.<br />
<br />
=== Odd and even rings maps (14 HFI)<br />
<br />
As the name indicates, these are generated by using only the odd or only the even rings.<br />
<br />
=== Caveats and known issues ===<br />
<br />
'''TBC'''<br />
<br />
==== Caveats when using the HFI frequency maps ====<br />
Some imperfections have shown up in the tests of the HFI PR3 maps that were previously hidden by higher-level systematics in the previous PR2 data. These lead to guidelines for the proper use of the HFI PR3 data.<br />
<br />
===== Monopoles =====<br />
Monopoles, which cannot be extracted from Planck data alone, are adjusted at each frequency (as was done in the previous PR2 release). For component separation, this provides maps that can be used directly in combination with other tracers.<br />
This monopole includes a CIB model, a diffuse ISM signal adjusted on the HI tracer, and a zodiacal emission signal adjusted to the proper absolute intensity.<br />
<br />
=====Use of the 353 GHz SWBs ===== <br />
We deliver two data sets: the recommended one not using the 353 GHz SWBs data, and the other one including the 353 GHz SWBs for specific use like, for example, increasing the signal to noise level at high multipoles.<br />
<br />
===== Color correction and component separation=====<br />
Different responses between bolometers to different foregrounds cannot be used with the PR3 release to extract component maps. Single bolometer maps computed by Sroll in a frequency band, are all adjusted by construction to the band average response.<br />
<br />
===== Sub-pixel effect in very bright regions===== <br />
The bandpass corrections have been optimized for high latitude regions which implied to reduce the noise of the CO and dust bandpass templates to avoid the introduction of significant correlated noise. The effect is negligible for dust but not for CO in very bright regions. See [[subpixel_HFI|detailled description]].<br />
<br />
===== Solar dipole residual===== <br />
The ''Planck'' 2015 Solar dipole is removed from the PR3 HFI maps to be consistent with LFI maps and to facilitate comparison with the previous PR2 ones. The best Solar dipole determination from HFI PR3 data shows a small shift in direction of about 1', but a 1.8 &mu;K lower amplitude. Removal of the ''Planck'' 2015 Solar dipole thus leaves a small but non-negligible dipole residual in the HFI PR3 maps. To correct for this, and adjust maps at the best photometric calibration, users of the HFI PR3 maps should:<br />
# put back into the maps the ''Planck'' 2015 Solar dipole (d,l,b)= (3364.5 &plusmn; 2.0 &mu;K, 264.00 &plusmn; 0.03&deg;, 48.24 &plusmn; 0.02&deg;),<br />
# include the [[#Calibration accuracy|absolute calibration frequency bias]], i.e., multiply by 1 minus the calibration bias,<br />
# lastly, remove the [[#HFI 2018 Solar dipole|HFI 2018 Solar dipole]].<br />
<br />
==Inputs==<br />
=== HFI inputs ===<br />
<br />
The HFI mapmaking takes as input:<br />
* the cleaned TOIs of the signal from each detector, together with their flags, produced by the [[TOI processing|TOI processing]] pipeline;<br />
* the TOIs of pointing (quaternions), described in [[Detector_pointing|Detector pointing]];<br />
* bolometer-level characterization data, from the DPC's internal IMO (not distributed);<br />
* Planck orbit data, used to compute and remove the Earth's dipole;<br />
* Planck solar dipole information, used to calibrate the CMB channels;<br />
* planet models used to calibrate the Galactic channels.<br />
<br />
=== LFI inputs ===<br />
<br />
The MADAM mapmaker takes as input:<br />
* the calibrated timelines (for details see [[TOI processing LFI|TOI Processing]]);<br />
* the detector pointings (for details see [[Detector_pointing|Detector pointing]]);<br />
* the noise information in the form of 3-parameter (white noise level &sigma;, slope, and knee frequency <i>f</i><sub>knee</sub>) noise model (for details see [[The RIMO|RIMO]]).<br />
<br />
==Related products==<br />
=== Masks ===<br />
This section presents the "general purpose" masks. Other masks specific to certain products are packaged with those products.<br />
<br />
Note that for this release, HFI has not produced any new masks. <br />
<br />
==== Gatactic Centre masks ====<br />
<br />
'''TBW'''<br />
<br />
<br />
====Point source masks [TO BE REMOVED ??]====<br />
<br />
For HFI and LFI two sets of point-source masks are provided. <br />
* Intensity masks, which remove sources detected with S/N > 5. <br />
* Polarisation masks, which remove sources that have polarization detection significance levels of 99.97 % or greater at the position of a source detected in intensity. They were derived from the polarization maps with dust foreground bandpass mismatch leakage corrections applied. The area excised around each source has a radius of 3σ (width) of the beam, i.e., 1.27 FWHM (for LFI the cut around each source has a radius of 32 arcmin at 30GHz, 27 arcmin at 44 GHz, and 13 arcmin at 70 GHz).<br />
<br />
Both sets of masks are found in the files ''HFI_Mask_PointSrc_2048_R2.00.fits'' and ''LFI_Mask_PointSrc_2048_R2.00.fits'', in which the first extension contains the intensity masks, and the second contains the polarization masks.<br />
<br />
====Galactic plane masks [TO BE REMOVED ??]====<br />
<br />
Eight Galactic emission masks are provided, giving 20, 40, 60, 70, 80, 90, 97, and 99% sky coverage, derived from the 353 GHz map after CMB subtraction. These are independent of frequency channel. Three versions are given: not apodized; and apodized by 2&deg; and 5&deg;. The filenames are ''HFI_Mask_GalPlane-apoN_2048_R2.00.fits'', where <i>N</i> = 0, 2, and 5.<br />
<br />
The masks are shown below. The eight "GalPlane" masks are combined (added together) and shown in a single figure for each of the three apodizations. While the result is quite clear for the case of no apodization, it is less so for the apodized case. The "PointSrc" masks are shown separately for the intensity case.<br />
<br />
<center><br />
<gallery perrow=3 widths=260px heights=160px ><br />
File: GalPlaneMask_apo0.png | '''Galactic plane masks, no apodization.'''<br />
File: GalPlaneMask_apo2.png | '''Galactic plane masks, apodized to 2&deg;.'''<br />
File: GalPlaneMask_apo5.png | '''Galactic plane masks, apodized to 5&deg;.'''<br />
File: PointSrcMask_100.png | '''Point source mask, 100 GHz.'''<br />
File: PointSrcMask_143.png | '''Point source mask, 143 GHz.'''<br />
File: PointSrcMask_217.png | '''Point source mask, 217 GHz.'''<br />
File: PointSrcMask_353.png | '''Point source mask, 343 GHz.'''<br />
File: PointSrcMask_545.png | '''Point source mask, 545 GHz.'''<br />
File: PointSrcMask_857.png | '''Point source mask, 857 GHz.'''<br />
</gallery><br />
</center><br />
<br />
== File names ==<br />
The FITS filenames are of the form ''{H|L}FI_SkyMap_fff{-tag}_Nside_R2.nn_{coverage}-{type}.fits'', where "fff" are three digits to indicate the Planck frequency band, "tag" indicates the single detector or the detset (no "tag" indicates full channel), "Nside" is the HEALPix <i>N</i><sub>side</sub> value of the map, "coverage" indicates which part of the mission is covered (full, half mission, survey, year, etc.), and the optional "type" indicates the subset of input data used. The table below lists the products by type, with the appropriate unix wildcards that form the full filename.<br />
<br />
{| class="wikitable" align="center" style="text-align"left" border="1" cellpadding="15" cellspacing="20" width=880px<br />
|+ '''HFI FITS filenames'''<br />
|- bgcolor="ffdead"<br />
! Coverage || Filename <br />
|-<br />
| Full channel, full mission ||HFI_SkyMap_fff{-tag}_2048_R3.??_full.fits<br />
|-<br />
| Full channel, half mission || HFI_SkyMap_fff{-tag}_2048_R3.??_halfmission-{1/2}.fits<br />
|-<br />
| Full channel, full mission, odd/even ring || HFI_SkyMap_fff{-tag}_2048_R3.??_{odd/even}ring.fits <br />
|}<br />
<br />
{| class="wikitable" align="center" style="text-align"left" border="1" cellpadding="15" cellspacing="20" width=1000px<br />
|+ '''LFI FITS filenames'''<br />
|- bgcolor="ffdead"<br />
! Coverage || Filename || Half-ring filename || Comment<br />
|-<br />
| Full channel, full mission ||LFI_SkyMap_???_1024_R2.??_full.fits ||LFI_SkyMap_???_1024_R2.??_full-ringhalf-?.fits || Available also at Nside = 2048<br />
|-<br />
| Full channel, single survey || LFI_SkyMap_???_1024_R2.??_survey-?.fits || n/a || Available also at <i>N</i><sub>side</sub>=2048<br />
|-<br />
| Full channel, survey combination || LFI_SkyMap_???_1024_R2.??_survey-1-3-5-6-7-8.fits || n/a || n/a<br />
|-<br />
| Full channel, single year || LFI_SkyMap_???_1024_R2.??_year-?.fits || n/a || Available also at <i>N</i><sub>side</sub>=2048<br />
|-<br />
| Full channel, year combination || LFI_SkyMap_???_1024_R2.??_year?-?.fits || n/a || n/a<br />
|-<br />
| Horn pair, full mission || LFI_SkyMap_???-??-??_1024_R2.??_full.fits || LFI_SkyMap_???_??-??_1024_R2.??_full-ringhalf-?.fits || Available also at <i>N</i><sub>side</sub>2048<br />
|-<br />
| Single radiometer, full mission || LFI_SkyMap_???-???_1024_R2.??_full.fits || LFI_SkyMap_???-???_1024_R2.??_full-ringhalf-?.fits || n/a<br />
|}<br />
<br />
For the benefit of users who are only looking for the frequency maps with no additional information, we also provide a file combining the nine frequency maps as separate columns in a single extension. The nine columns in this file contain the intensity maps <i>only</i> and no other information (hits maps or variance maps) is provided.<br />
<br />
== FITS file structure ==<br />
<br />
The FITS files for the sky maps contain a minimal primary header with no data, and a ''BINTABLE'' extension (EXTENSION 1, EXTNAME = ''FREQ-MAP'') containing the data. The structure is shown schematically in the figure below. The ''FREQ-MAP'' extension contains a 3- or 10-column table that contain the signal, hit-count, and variance maps, all in HEALPix format. The 3-column case is for intensity only maps, while the 10-column case is for polarization. The number of rows is the number of map pixels, which is <i>N</i><sub>pix</sub> = 12 <i>N</i><sub>side</sub><sup>2</sup> for HEALPix maps, where <i>N</i><sub>side</sub> = 1024 or 2048 for most the maps presented in this section.<br />
<br />
[[File:FITS_FreqMap.png | 550px | center | thumb | '''FITS file structure.''']]<br />
<br />
Note that file sizes are approximately 0.6 GB for <i>I</i>-only maps and 1.9 GB for <i>IQU</i> maps at <i>N</i><sub>side</sub>=2048, but about 0.14 GB for <i>I</i>-only maps and 0.45 GB for <i>IQU</i> maps at <i>N</i><sub>pix</sub>=1024 .<br />
<br />
Keywords indicate the coordinate system ("GALACTIC"), the HEALPix ordering scheme ("NESTED"), the units (K<sub>CMB</sub> or MJy.sr<sup>-1</sup>) of each column, and of course the frequency channel ("FREQ"). Where polarization <i>Q</i> and <i>U</i> maps are provided, the "COSMO" polarization convention (used in HEALPix) is adopted, and it is specified in the "POLCCONV" keyword (see [[Sky_temperature_maps#Polarization_convention_used_in_the_Planck_project|this section]]). The "COMMENT" fields give a one-line summary of the product, and some other information useful for traceability within the DPCs. The original filename is also given in the "FILENAME" keyword. The "BAD_DATA" keyword gives the value used by HEALPix to indicate pixels for which no signal is present (these will also have a hit-count value of 0). The main parameters are summarized in the table below.<br />
<br />
{| border="1" cellpadding="3" cellspacing="0" align="center" style="text-align:left" width=800px<br />
|+ '''Sky map file data structure'''<br />
|- bgcolor="ffdead" <br />
!colspan="4" | 1. EXTNAME = 'FREQ-MAP' : Data columns<br />
|- bgcolor="ffdead" <br />
! Column name || Data type || Units || Description<br />
|-<br />
|I_STOKES || Real*4 || K<sub>CMB</sub> or MJy.sr<sup>-1</sup> || Stokes <i>I</i> map<br />
|-<br />
|Q_STOKES || Real*4 || K<sub>CMB</sub> or MJy.sr<sup>-1</sup> || Stokes <i>Q</i> map (optional)<br />
|-<br />
|U_STOKES || Real*4 || K<sub>CMB</sub> or MJy.sr<sup>-1</sup> || Stokes <i>U</i> map (optional)<br />
|-<br />
|HITS || Int*4 || none || The hit-count map<br />
|-<br />
|II_COV || Real*4 || K<sub>CMB</sub><sup>2</sup> or (MJy.sr<sup>-1</sup>)<sup>2</sup> || <i>II</i> variance map<br />
|-<br />
|IQ_COV || Real*4 || K<sub>CMB</sub><sup>2</sup> or (MJy.sr<sup>-1</sup>)<sup>2</sup> || <i>IQ</i> variance map (optional)<br />
|-<br />
|IU_COV || Real*4 || K<sub>CMB</sub><sup>2</sup> or (MJy.sr<sup>-1</sup>)<sup>2</sup> || <i>IQ</i> variance map (optional)<br />
|-<br />
|QQ_COV || Real*4 || K<sub>CMB</sub><sup>2</sup> or (MJy.sr<sup>-1</sup>)<sup>2</sup> || <i>QQ</i> variance map (optional)<br />
|-<br />
|QU_COV || Real*4 || K<sub>CMB</sub><sup>2</sup> or (MJy.sr<sup>-1</sup>)<sup>2</sup> || <i>QU</i> variance map (optional)<br />
|-<br />
|UU_COV || Real*4 || K<sub>CMB</sub><sup>2</sup> or (MJy.sr<sup>-1</sup>)<sup>2</sup> || <i>UU</i> variance map (optional)<br />
|-<br />
|- bgcolor="ffdead" <br />
! Keyword || Data type || Value || Description<br />
|-<br />
|PIXTYPE || String || HEALPIX ||<br />
|-<br />
|COORDSYS || String || GALACTIC ||Coordinate system <br />
|-<br />
|ORDERING || String || NESTED || Healpix ordering<br />
|-<br />
|POLCCONV || String || COSMO || Polarization convention<br />
|-<br />
|NSIDE || Int || 1024 or 2048 || HEALPix <i>N</i><sub>side</sub> <br />
|-<br />
|FIRSTPIX || Int*4 || 0 || First pixel number<br />
|-<br />
|LASTPIX || Int*4 || 12 <i>N</i><sub>side</sub><sup>2</sup> – 1 || Last pixel number<br />
|-<br />
|FREQ || String || nnn || Frequency channel <br />
|}<br />
<br />
<br />
The same structure applies to all "SkyMap" products, independent of whether they are full channel, survey of half-ring. The distinction between the types of maps is present in the FITS filename (and in the traceability comment fields).<br />
<br />
==Polarization convention used in the Planck project==<br />
<br />
The FITS keyword "POLCCONV" defines the polarization convention of the data within the file.<br />
The Planck collaboration used the COSMO convention for the polarization angle (as usually adopted in space-based and other CMB missions), whereas other subfields of astronomy usually adopt the IAU convention. The basic difference comes down to whether one thinks of the light rays being emitted from the origin (the usual mathematics/physics convention) or converging on the observer from the sky (the usual astronomy convention), and hence the "obvious" choice is different for a physicists and for an astronomer. Given that CMB results are of interest to a wide range of both physicists and astronomers, there is no single choice of convention that everyone would regard as self-evident. Hence one simply has to be aware of the convention being adopted. Because of this the Planck Collaboration has taken pains to point out which convention is being used in publications and in data releases. In the following we describe the difference between these two conventions, and the consequence if it is <i>not</i> taken into account correctly in the analysis.<br />
<br />
[[File:conventions.png|thumb|center|400px|'''Figure 1. Polarization conventions, showing the COSMO convention (left) and IAU convention (right). The vector <math>\hat{z}</math> points in the outward direction in COSMO, and inwards in IAU. The bottom panel refers to the plane tangent to the sphere.''']]<br />
<br />
Changing the orientation convention is equivalent to a transformation &psi;'=&pi;-&psi; of the polarization angle (Figure 1). The consequence of this transformation is the inversion of the Stokes parameter <i>U</i>.<br />
The components of the polarization tensor in the helicity basis <math>\epsilon^{\pm}=(\hat{x}\pm i\hat{y})/\sqrt{2}</math> are<br />
<br />
<math><br />
(Q+iU)(\hat{n}) = \sum _{\ell m}a_{2,lm}{}_{2}Y_{\ell }^{m}(\hat{n}),<br />
\\(Q-iU)(\hat{n}) = \sum _{\ell m}a_{-2,lm}{}_{2}Y_{\ell }^{m}(\hat{n}),<br />
</math><br />
<br />
where <math>{}_{2}Y_{\ell }^{m}(\hat{n})</math> are the spin-weighted spherical harmonic functions.<br />
The <i>E</i> and <i>B</i> modes can be defined as<br />
<br />
<math><br />
E(\hat{n}) = \sum_{\ell m}a_{E,\ell m}Y_{\ell }^{m}(\hat{n}),<br />
\\B(\hat{n}) = \sum_{\ell m}a_{B,\ell m}Y_{\ell }^{m}(\hat{n}),<br />
</math><br />
<br />
where the coefficients <i>a<sub>E,&#8467;m</sub></i> and <i>a<sub>B,&#8467;m</sub></i> are derived from linear combinations of the <i>a<sub>2,&#8467;m</sub></i>, <i>a<sub>-2,&#8467;m</sub></i>, defined implicitly in the first equation (<i>Q</i>&plusmn; i<i>U</i>).<br />
<br />
[[File:test_gradient.jpg|thumb|center|400px|]]<br />
[[File:test_curl.jpg|thumb|center|400px|'''Figure 2. Error on Planck-LFI 70 GHz <i>EE</i> (top) and <i>BB</i> (bottom) power spectra, in the case of an incorrect choice being made for the polarization coordinate system convention (IAU instead of COSMO).''']]<br />
<br />
The effect of the sign inversion of <i>U</i> on the polarization spectra is a non-trivial mixing of <i>E</i> and <i>B</i> modes. <br />
An example of the typical error on <i>EE</i> and <i>BB</i> auto-spectra in the case of the wrong choice for the polarization basis is shown in Figure 2.<br />
<br />
<i>One should be careful</i> to be aware of the polarization convention that is being adopted. If the IAU convention is used in computing the power spectra, then the sign of the <i>U</i> component of the Planck maps must be inverted before computing the <i>E</i> and <i>B</i> modes.<br />
<br />
In astronomical applications it is common to define a pseudo-vector <i>P</i> to show the amplitude and orientation of<br />
polarization on a map. When plotting these line segments to show the orientation of the plane of polarization (or the orthogonal direction, often considered to be the projection of the magnetic field), the results are the same for both the COSMO and IAU conventions. This because the appearance of <i>P</i> is a property of the radiation and hence not affected by the sign of <i>U</i>.<br />
<br />
=== Note on the convention used in the Planck Catalogue of Compact Sources (PCCS) ===<br />
Planck non-cosmology papers sometimes follow the IAU convention for internal analysis, for ease of comparison with other studies (e.g., comparison of Planck-derived thermal dust emission polarization with the optical polarization of starlight). Nevertheless, Planck data products, such as component-separated maps, still use the COSMO convention. The one exception is for the compact source catalogue. Because catalogues of astronomical objects found by Planck need to be compared directly with other source catalogues, the polarized sources described in the Planck Catalogue of Compact Sources follow the IAU convention, and the polarization angles are defined on an interval of [-90&deg;,90&deg;]. To switch to the COSMO convention, the polarization angles listed in the catalogue should be shifted by 90&deg; and multiplied by -1.<br />
<br />
== References ==<br />
<References /><br />
<br />
<br />
<span style="background:green"><br />
<br />
<span style="background:green"><br />
== Previous releases ==<br />
<br />
<div class="toccolours mw-collapsible mw-collapsed" style="background-color: #FFDAB9;width:80%" ><br />
'''2015 Sky temperature and polarization maps'''<br />
<br />
<div class="mw-collapsible-content"><br />
<br />
<br />
'''General description'''<br />
<br />
Sky maps give the best estimate of the intensity and polarization (Stokes Q and U components), if available, of the signal from the sky after removal, as far as possible, of known systematic effects (mostly instrumental, but including also the solar and earth-motion dipole, Galactic strylight and the Zodiacal light). Sky maps are provided for the full Planck mission using all valid detectors in each frequency channel, and also for various subsets by splitting the mission in various time ranges or in subsets of the detectors in a given channel. These products are useful for the study of source variability, but they are especially interesting for characterisation purposes (see also the [[HFI-Validation | data validation]] section). The details of the start and end of the time ranges are given in the table below.<br />
<br />
To help in further processing, there are also masks of the Galactic Plane and of point sources, each provided for several different depths.<br />
<br />
All sky maps are in Healpix format, with Nside of 1024 (LFI 30, 44 and 70) and 2048 (LFI 70 and HFI), in Galactic coordinates, and Nested ordering. <br />
<br />
;WARNING: the Healpix convention for polarization is NOT the same as the IAU convention - see Section 8 in this page.<br />
<br />
The signal is given in units of K<sub>cmb</sub> for 30-353 GHz, and of MJy/sr (for a constant <math>\nu F_\nu</math> energy distribution ) for 545 and 857 GHz. For each frequency channel, the intensity and polarization maps are packaged into a ''BINTABLE'' extension of a FITS file together with a hit-count map (or hit map, for short, giving the number of observation samples that are cumulated in a pixel, all detectors combined) and with the variance and covariance maps. Additional information is given in the FITS file header. The structure of the FITS file is given in the [[#FITS_file_structure | FITS file structure]] section below. <br />
<br />
; R2.00 : this first release (Jan 2015) contains polarisation data for the 353 GHz channel only.<br />
; R2.01 : this second release (May 2015) adds polarisation data to the 100-217 GHz channels.<br />
; R2.02 : a full re-release to correct the Healpix bad pixel value in the maps which was altered during the preparation of the maps and not reset to the correct value (the valid pixels are unchanged). It also fixes some FITS keywords, and includes a full re-release of the Zodi correction maps, with the 100-217 GHz one now including the polarisation correction)<br />
<br />
{| border="1" cellpadding="3" cellspacing="0" align="center" style="text-align:left" width=800px<br />
|+ '''Ranges for mission and surveys'''<br />
|- bgcolor="ffdead" <br />
! Range || ODs || HFI rings || pointing-IDs || Comment<br />
|-<br />
|nominal mission || 91 - 563 || 240 - 14723 || 00004200 - 03180200 ||<br />
|-<br />
|full mission || 91 - 974 || 240 - 27005 || 00004200 - 05322620 || for HFI<br />
|-<br />
|full mission || 91 - 1543 || n/a || 00004200 - 06511160 || for LFI<br />
|-<br />
|Survey 1 || 91 - 270 || 240 - 5720 || 00004200 - 01059820 ||<br />
|-<br />
|Survey 2 || 270 - 456 || 5721 - 11194 || 01059830 - 02114520 ||<br />
|-<br />
|Survey 3 || 456 - 636 || 11195 - 16691 || 02114530 - 03193660 ||<br />
|-<br />
|Survey 4 || 636 - 807 || 16692 - 21720 || 03193670 - 04243900 ||<br />
|-<br />
|Survey 5 || 807 - 974 || 21721 - 27005 || 05267180 - 05322590 || end of mission for HFI<br />
|-<br />
|Survey 5 || 807 - 993 || n/a || 05267180 - 06344800 || end of survey for LFI<br />
|-<br />
|Survey 6 || 993 - 1177 || n/a || 06344810 - 06398120 || LFI only <br />
|-<br />
|Survey 7 || 1177 - 1358 || n/a || 06398130 - 06456410 || LFI only <br />
|-<br />
|Survey 8 || 1358 - 1543 || n/a || 06456420 - 06511160 || LFI only <br />
|-<br />
|Survey 9 || 1543 - 1604 || n/a || 06511170 - 06533320 || LFI only Not in this delivery<br />
|-<br />
|HFI mission-half-1 || 91 - 531 || 240 - 13471 || 00004200 - 03155580 ||<br />
|-<br />
|HFI mission-half-2 || 531 - 974 || 13472 - 27005 || 03155590 - 05322590 ||<br />
|-<br />
|LFI Year 1 || 91 - 456 || n/a || 00004200 - 02114520 ||<br />
|-<br />
|LFI Year 2 || 456 - 807 || n/a || 02114530 - 04243900 ||<br />
|-<br />
|LFI Year 3 || 807 - 1177 || n/a || 05267180 - 06398120 ||<br />
|-<br />
|LFI Year 4 || 1177 - 1543 || n/a || 06398130 - 06511160 ||<br />
|-<br />
|}<br />
<br />
'''Production process'''<br />
<br />
Sky maps are produced by combining appropriately the data of all working detectors in a frequency channel over some period of the mission. They give the best estimate of the signal from the sky (unpolarised) after removal, as far as possible, of known systematic effects and of the dipole signals induced by the motion of the solar system in the CMB and of the Planck satellite in the solar system. In particular, they include the Zodiacal light emission (Zodi for short) and also the scattering from the far-side lobes of the beams (FSL). More on this below.<br />
<br />
''' HFI processing '''<br />
<br />
The mapmaking and calibration process is described in detail in the [[Map-making_LFI | Map-making]] section and in the {{PlanckPapers|planck2014-a09}} paper, where detailed references are found. In brief it consists of:<br />
<br />
; binning the TOI data onto ''rings'' : Healpix rings (HPRs) are used here, each ring containing the combined data of one pointing period. <br />
; flux calibration : at 100-353 GHz, the flux calibration factors are determined by correlating the signal with the orbital dipole, which is determined very accurately from the Planck satellite orbital parameters provided by Flight Dynamics. This provides a single gain factor per bolometer. At 545 and 857 GHz the gain is determined from the observation of Uranus and Neptune (but not Jupiter which is too bright) and comparison to recent models made explicitly for this mission. A single gain is applied to all rings at these frequencies.<br />
; destriping : in order to remove low-frequency noise, an offset per ring is determined by minimizing the differences between HPRs at their crossings, and removed.<br />
; Zodiacal light correction : a Zodiacal light model is used to build HPRs of the the Zodi emission, which is subtracted from the calibrated HPRs.<br />
; projection onto the map : the offset-corrected, flux-calibrated, and Zodi-cleaned HPRs are projected onto Healpix maps, with the data of each bolometer weighted by a factor of 1/NET of that bolometer.<br />
<br />
These steps are followed by some post-processing which is designed to prepare the maps for the component separation work. This post processing consists of: <br />
<br />
; Dust bandpass leakage correction : the Q and U maps are corrected for the intensity-to-polarisation leakage caused by the foregrounds having a non-CMB spectrum, and as a consequence of the non-identical bandpasses on the different detectors (bandpass mismatch, or BPM). This correction is determined using the ''ground'' method as described in Section 7.3 of {{PlanckPapers|planck2014-a09}}. These correction maps can be found in the Planck Legacy Archive as ''HFI_CorrMap_???-dustleak-ground_2048_R2.0?_{coverage}.fits''. The correction is applied by subtracting the correction map from the corresponding input map. This correction is not applied to the nominal mission maps in order to maintain compatibility with the PR1 products. ''In fact this correction was computed and applied only to the products used in component separation'', so they were not applied to the single survey maps and to the half-ring maps, which are considered characterisation products.<br />
; Far Side Lobe calibration correction : the 100-217 maps are multiplied by factors of 1.00087, 1.00046, and 1.00043, respectively, to compensate for the non-removal of the far-side lobes, and similarly the corresponding covariance maps have also been corrected by multiplication by the square of the factor.<br />
; Fill missing pixels : missing pixels are filled in with a value that is the mean of valid pixels within a given radius. A radius of 1 deg is used for the full channel maps, and 1.5 deg is used for the detset maps. This step is not applied to the single survey maps since they have large swaths of the sky that are not covered.<br />
<br />
; Map zero-level : for the 100 to 857 GHz maps, the zero levels are set to their optimal levels for Galactic and CIB studies. A procedure for adjusting them to astrophysical values is given in the HFI Mapmaking and Calibration paper {{PlanckPapers|planck2014-a09}}.<br />
<br />
These maps provide the main mission products. Together with signal maps, hit count, variance, and variance maps are also produced. The hit maps give the (integer) number of valid TOI-level samples that contribute to the signal of each pixel. All valid samples are counted in the same way, i.e., there is no weighting factor applied. The variance maps project the white noise estimate, provided by the NETs, in the sky domain.<br />
<br />
Note that the nominal mission maps have not had the post-processing applied, which makes them more easily comparable to the PR1 products.<br />
<br />
''' LFI processing '''<br />
LFI maps were constructed with the Madam map-making code, version 3.7.4. The code is based on generalized destriping technique, where the correlated noise component is modeled as a sequence of constant offset, called baselines. A noise filter was used to constrain the baseline solution allowing the use of 0.25 s and 1 second baselines for the 30 and 44, 70 GHz respectively.<br />
<br />
Radiometers were combined according to the horn-uniform weighting scheme to minimize systematics. The used weights are listed in [[Map-making LFI#Map-making|Map-making]]. The flagged samples were excluded from the analysis by setting their weights to <math>C_{w}^{-1}</math> = 0. The galaxy region was masked out in the destriping phase, to reduce error arising from strong signal gradients. The polarization component was included in the analysis... <br />
<br />
; Dipole and Far Side Lobe correction : input timelines are cleaned by 4pi convolved dipole and Galactic Straylight obtained as convolution of the 4pi in band far sidelobes and Galactic Simulation as explained in Section 7.4 of {{PlanckPapers|planck2014-a03}}. <br />
<br />
Beam effects on the LFI maps are described in Section 7.1 of {{PlanckPapers|planck2014-a03}}. Scaling of the maps due to beam effects is taken into account in the LFI's beam functions (as provided in the RIMO, give reference) which should be used for analysis of diffuse components. To compute the flux densities of compact sources, correction must be made for beam effects (see Table 8 of {{PlanckPapers|planck2014-a03}})."<br />
<br />
; Bandpass leakage correction : '''as opposed to the HFI, the LFI high resolution maps have not been corrected for bandpass leakage. Only low resolution (nside 256) maps are provided with the bandpass correction'''. The correction maps (LFI_CorrMap_0??-BPassCorr_*.fits) can be found in the Planck Legacy Archive. Further details about the procedure used to generate the bandpass correction maps can be found in Section 11 of {{PlanckPapers|planck2014-a03}}.<br />
<br />
; Map zero-level : for the 30, 44 and 70 GHz, maps are corrected for zero level monopole by applying an offset correction, see LFI Calibration paper {{PlanckPapers|planck2014-a06}}. Note that the offset applied is indicated in the header as a comment keyword.<br />
<br />
A detailed description of the map-making procedure is given in {{PlanckPapers|planck2013-p02}}, {{PlanckPapers|planck2014-a03}}, {{PlanckPapers|planck2014-a07}} and in section [[Map-making LFI#Map-making|Map-making]].<br />
<br />
'''Types of maps '''<br />
<br />
''' Full mission, full channel maps (6 HFI, 4 LFI)'''<br />
<br />
Full channel maps are built using all the valid detectors of a frequency channel and cover the either the full or the nominal mission. For HFI, the 143-8 and 545-3 bolometers are rejected entirely as they are seriously affected by RTS noise. HFI provides the Q and U components for the 100, 143, 217 and 353 GHz channels only. LFI provides the I, Q and U maps for all the channels. Reminder: HFI Q and U maps are corrected for bandpass leakage but LFI Q and U maps are not. The I, Q and U maps are displayed in the figures below. The color range is set using a histogram equalisation scheme (from HEALPIX) that is useful for these non-Gaussian data fields. For visualization purposes, the Q and U maps shown here have been smoothed with a 1 degree Gaussian kernel, otherwise they look like noise to the naked eye.<br />
The 70 GHz full map is available also at <math>N_{side}</math> 2048.<br />
<br />
<center><br />
<gallery style="padding:0 0 0 0;" perrow=3 widths=260px heights=160px> <br />
File: SkyMap30e.png| '''Full mission I, 30 GHz'''<br />
File: SkyMap44e.png | '''Full mission I, 44 GHz'''<br />
File: SkyMap70e.png | '''Full mission I, 70 GHz'''<br />
File: SkyMap100e.png | '''Full mission I, 100 GHz'''<br />
File: SkyMap143e.png | '''Full mission I, 143 GHz'''<br />
File: SkyMap217e.png | '''Full mission I, 217 GHz'''<br />
File: SkyMap353e.png | '''Full mission I, 353 GHz'''<br />
File: SkyMap545e.png | '''Full mission I, 545 GHz'''<br />
File: SkyMap857e.png | '''Full mission I, 857 GHz'''<br />
</gallery><br />
</center><br />
<br><br />
<center><br />
<gallery style="padding:0 0 0 0;" perrow=3 widths=260px heights=160px> <br />
File: LFI_SkyMap_030_1024_R2.01_full_Qb_sm1deg.png| '''Full mission Q, 30 GHz'''<br />
File: LFI_SkyMap_044_1024_R2.01_full_Qb_sm1deg.png | '''Full mission Q, 44 GHz'''<br />
File: LFI_SkyMap_070_1024_R2.01_full_Qb_sm1deg.png | '''Full mission Q, 70 GHz'''<br />
File: HFI_Skymap_100_full_bplcorrected_sm1deg_Qb.png | '''Full mission Q, 100 GHz'''<br />
File: HFI_Skymap_143_full_bplcorrected_sm1deg_Qb.png | '''Full mission Q, 143 GHz'''<br />
File: HFI_Skymap_217_full_bplcorrected_sm1deg_Qb.png | '''Full mission Q, 217 GHz'''<br />
File: HFI_Skymap_353_full_bplcorrected_sm1deg_Qb.png | '''Full mission Q, 353 GHz'''<br />
</gallery><br />
</center><br />
<br><br />
<center><br />
<gallery style="padding:0 0 0 0;" perrow=3 widths=260px heights=160px> <br />
File: LFI_SkyMap_030_1024_R2.01_full_Ub_sm1deg.png| '''Full mission U, 30 GHz'''<br />
File: LFI_SkyMap_044_1024_R2.01_full_Ub_sm1deg.png | '''Full mission U, 44 GHz'''<br />
File: LFI_SkyMap_070_1024_R2.01_full_Ub_sm1deg.png | '''Full mission U, 70 GHz'''<br />
File: HFI_Skymap_100_full_bplcorrected_sm1deg_Ub.png | '''Full mission U, 100 GHz'''<br />
File: HFI_Skymap_143_full_bplcorrected_sm1deg_Ub.png | '''Full mission U, 143 GHz'''<br />
File: HFI_Skymap_217_full_bplcorrected_sm1deg_Ub.png | '''Full mission U, 217 GHz'''<br />
File: HFI_Skymap_353_full_bplcorrected_sm1deg_Ub.png | '''Full mission U, 353 GHz'''<br />
</gallery><br />
<br />
</center><br />
<br />
''' Full mission light maps, full channel maps (6 HFI, 7 LFI) '''<br />
<br />
These maps are based on the Full mission maps but contain fewer columns, IQU from 30 to 353 GHz, and I only at 545 and 857 GHz. These maps have been produced to reduce the transfer time of the most downloaded frequency full mission maps.<br />
<br />
''' Nominal mission, full channel maps (6 HFI) '''<br />
<br />
These maps are similar to the ones above, but cover the nominal mission only. They are meant primarily to be compared to the PR1 products in order to see the level of improvements in the processing. Because of this, they are produced in Temperature only, and have not had the post-processing applied.<br />
<br />
''' Single survey, full channel maps (30 HFI, 35 LFI)'''<br />
<br />
Single survey maps are built using all valid detectors of a frequency channel; they cover separately the different sky surveys. The surveys are defined as the times over which the satellite spin axis rotates but 180 degrees, which, due to the position of the detectors in the focal plane does not cover the full sky, but a fraction between ~80 and 90% depending on detector position. During adjacent surveys the sky is scanned in opposite directions. More precisely it is the ecliptic equator that is scanned in opposite directions. While these are useful to investigate variable sources, they are also used to study the systematics of the time-response of the detectors as they scan bright sources, like the Galactic Plane, in different directions during different survey. Note that the HFI and LFI missions cover 5 and 8 surveys, respectively, and in case of HFI the last survey in incomplete.<br />
The 70 GHz surveys maps are available also at <math>N_{side}</math> 2048.<br />
Note LFI provide a special surveys maps combination used in the low l analysis. This maps, available at the three LFI frequency 30, 44 and 70 GHz, was built using the combination of survey 1, 3, 5, 6, 7 and 8. <br />
<br />
''' Year maps, full channel maps (12 HFI, 16 LFI)'''<br />
<br />
These maps are built using the data of surveys 1+2, surveys 3+4, and so forth. They are used to study long-term systematic effects.<br />
The 70 GHz years maps are available also at <math>N_{side}</math> 2048.<br />
<br />
'''Half-mission maps, full channel maps (12 HFI, 12 LFI)'''<br />
<br />
For HFI, the half mission is defined after eliminating those rings discarded for all bolometers. There are 347 such rings, may of which are during the 5th survey when the ''End-of-Life'' tests were performed. The remaining 26419 rings are divided in half (up to the odd ring) to define the two halves of the mission. This exercise is done for the full mission only.<br />
<br />
For LFI instead of the half-mission the following year combination has been created: Year 1+2, Year 1+3, Year 2+4, Year 3+4, <br />
<br />
'''Full mission, single detector maps (18 HFI, 22 LFI)'''<br />
<br />
IN case of HFI these maps are built only for the SWBs (non polarized) and contain only temperature data, of course. They are not built for the polarisation sensitive detectors because they are not fixed on the sky as the polarisation component depends on the position angle at the time of observation. Instead, we provide maps built by ''quads'' of polarisation-sensitive detectors (see next section), which have different polarisation angles and that can be used to built I, Q, and U maps<br />
<br />
{| border="1" cellpadding="3" cellspacing="0" align="center" style="text-align:left" width=600px<br />
|+ '''HFI Temperature sensitive bolometers'''<br />
|- bgcolor="ffdead" <br />
!Frequency || Detector names<br />
|-<br />
|143 GHz || 143-5, 6, 7<br />
|-<br />
|217 GHz || 217-1, 2, 3, 4<br />
|-<br />
|353 GHz || 353-1, 2, 7, 8<br />
|-<br />
|545 GHz || 545-1, 2, 4<br />
|-<br />
|857 GHz || 857-1, 2 , 3, 4<br />
|}<br />
<br />
The 143-8 and 353-3 bolometer data are affected by strong RTS (random telegraphic signal) noise. They have not been used in the data processing, and are not delivered. For a figure showing the focal plane layout, see [[Detector_pointing#Introduction_and_Summary | this Introduction]] of the Detector Pointing chapter.<br />
<br />
In case of LFI, all the 22 Radiometers maps are available, those, obviously, are only in temperature.<br />
<br />
'''Full mission, detector set or detector pairs maps (8 HFI, 8 LFI)'''<br />
<br />
The objective here is to build independent temperature (I) and polarisation (Q and U) maps with the two pairs of polarisation sensitive detectors of each channel where they are available, i.e. in the 44-353 GHz channels. The table below indicates which detectors were used to built each detector set (detset).<br />
<br />
<br />
{| border="1" cellpadding="3" cellspacing="0" align="center" style="text-align:left" width=600px<br />
|+ '''Definition of HFI Detector Sets'''<br />
|- bgcolor="ffdead" <br />
!Frequency || DetSet1 || DetSet2 <br />
|-<br />
|100 GHz || 100-1a/b & 100-4a/b || 100-2a/b & 100-3a/b<br />
|-<br />
|143 GHz || 143-1a/b 1 & 43-3a/b || 143-2a/b & 143-4a/b<br />
|-<br />
|217 GHz || 217-5a/b & 217-7a/b || 217-6a/b & 217-8a/b<br />
|-<br />
|353 GHz || 353-3a/b & 353-5a/b || 353-4a/b & 353-6a/b<br />
|}<br />
<br />
{| border="1" cellpadding="3" cellspacing="0" align="center" style="text-align:left" width=600px<br />
|+ '''Definition of LFI Detector Pairs'''<br />
|- bgcolor="ffdead" <br />
!Frequency || Horn Pair || Comment <br />
|-<br />
|44 GHz || 24 || This maps is only in temperature<br />
|-<br />
|44 GHz || 25 & 26 || <br />
|-<br />
|70 GHz || 18 & 23 || Available also at <math>N_{side}</math> = 2048<br />
|-<br />
|70 GHz || 19 & 22 || Available also at <math>N_{side}</math> = 2048<br />
|-<br />
|70 GHz || 20 & 21 || Available also at <math>N_{side}</math> = 2048<br />
|}<br />
<br />
<br />
'''Half-ring maps (64 HFI, 62 LFI)'''<br />
<br />
These maps are similar to the ones above, but are built using only the first or the second half of each ring (or pointing period). The HFI provides half-ring maps for the full mission only, and for the full channel, the detsets, and the single bolometers. The LFI provides half-rings maps for the channel full mission (70 GHz also at <math>N_{side}</math> 2048), for the radiometer full mission and the horn pairs full mission.<br />
<!----<br />
'''Masks'''<br />
<br />
Masks are provided of the Galactic Plane and of the point sources. For the Galactic Plane, eight masks are given covering different fractions of the sky, and for the points sources two masks are given, at the 5 and 10 sigma level, for each Planck HFI and LFI frequency channel. These are generic masks, specific masks applicable to other products are delivered with the products themselves.<br />
---><br />
<br />
''' The Zodiacal light correction maps '''<br />
<br />
The Zodiacal light signal depends on the location of the observer relative to the Zodiacal light bands, and thus it is not a fixed pattern on the sky but depends on the period of observation. The maps presented here are the difference between the uncorrected (and not delivered) and the corrected maps. <br />
<br />
Note that while the Zodiacal light model that is subtracted at ring level (see [[Map-making#Zodiacal_light_correction | here]]) is not polarised, the corrections are not null and Q and U. This is suspected to come from some combination of leakage due to bandpass differences and beam mismatch, and maybe other effects. These leakages are typically of order a few %, at max, of the maximum zodi intensity at I for each channel. They range from ~150 nK at 100 GHz to ~5 uK at 353 GHz.<br />
<br />
''' Caveats and known issues '''<br />
<br />
; HFI polarization 100-217 GHz : at low multipoles, despite the progress that has been made to control the systematic effects present in the maps, polarization data between 100-217 GHz are still contaminated by systematic residuals. Figure 10 of {{PlanckPapers|planck2014-a09}} shows the EE power spectra from the half-difference maps at 100, 143, and 217 GHz and compared to the noise power spectrum from FFP8 simulations. he half-ring differences are compatible with noise while, at multipoles typically lower than 50, detector-set and half-mission differences are dominated by excess power which is larger than the EE CMB signal. The Planck Collaboration has used the range ell>30 to carry out component separation ({{PlanckPapers|planck2014-a11}}), as data at ell<30 is not considered usable for cosmological analyses. The origin of the excess power will be explored in a forthcoming publication.<br />
<br />
<br />
'''Inputs'''<br />
''' HFI inputs '''<br />
<br />
The HFI mapmaking takes as input:<br />
* the cleaned TOIs of signal of each detector, together with their flags, produced by the [[TOI processing|TOI processing]] pipeline;<br />
* the TOIs of pointing (quaternions), described in [[Detector_pointing|Detector pointing]];<br />
* bolometer-level characterization data, from the DPC's internal IMO (not distributed);<br />
* Planck orbit data, used to compute and remove the Earth's dipole;<br />
* Planck solar dipole information, used to calibrate the CMB channels;<br />
* Planet models used to calibrate the Galactic channels.<br />
<br />
''' LFI inputs '''<br />
<br />
The Madam mapmaker takes as input:<br />
<br />
* the calibrated timelines (for details see [[TOI processing LFI|TOI Processing]]);<br />
* the detector pointings (for details see [[Detector_pointing|Detector pointing]]);<br />
* the noise information in the form of 3-parameter (white noise level, &sigma;, slope, and knee frequency, <i>f</i><sub>knee</sub>) noise model (for details see [[The RIMO|RIMO]])<br />
<br />
'''Related products'''<br />
''' Masks '''<br />
<br />
This section presents the masks of the point sources and of the Galactic plane. These are ''general purpose'' masks. Other masks specific to certain products are packaged with the products.<br />
<br />
'''Point source masks'''<br />
<br />
For HFI and LFI two sets of masks are provided: <br />
* Intensity masks, which removes sources detected with SNR > 5. <br />
* Polarisation masks, which remove sources which have polarisation detection significance of 99.97 % or greater at the position of a source detected in intensity. They were derived from the polarisation maps with dust ground bandpass mismatch leakage correction applied. The cut around each source has a radius of 3σ (width) of the beam ~ 1.27 FWHM (for LFI the cut around each source has a radius of 32 arcmin at 30GHz, 27 arcmin at 44 GHz and 13 arcmin at 70 GHz).<br />
<br />
Both sets are found in the files ''HFI_Mask_PointSrc_2048_R2.00.fits'' and ''LFI_Mask_PointSrc_2048_R2.00.fits'' in which the first extension contains the Intensity masks, and the second contains the Polarisation masks.<br />
<br />
'''Galactic plane masks'''<br />
<br />
Eight masks are provided giving 20, 40, 60, 70, 80, 90, 97, and 99% sky coverage derived from the 353 GHz map, after CMB subtraction. They are independent of frequency channel. Three versions of these are given: not apodized, and apodized by 2 and 5 deg. The filenames are ''HFI_Mask_GalPlane-apoN_2048_R2.00.fits'', where N = 0, 2, 5.<br />
<br />
The masks are shows below. The 8 GalPlane masks are combined (added together) and shown in a single figure for each of the three apodization. While the result is quite clear for the case of no apodization, it is less so for the apodized case. The point source masks are shown separately for the Intensity case.<br />
<br />
<center><br />
<gallery perrow=3 widths=260px heights=160px ><br />
File: GalPlaneMask_apo0.png | '''Galactic Plane masks, no apod'''<br />
File: GalPlaneMask_apo2.png | '''Galactic Plane masks, apod 2 deg'''<br />
File: GalPlaneMask_apo5.png | '''Galactic Plane masks, apod 5 deg'''<br />
File: PointSrcMask_100.png | '''PointSource mask 100 GHz'''<br />
File: PointSrcMask_143.png | '''PointSource mask 143 GHz'''<br />
File: PointSrcMask_217.png | '''PointSource mask 217 GHz'''<br />
File: PointSrcMask_353.png | '''PointSource mask 343 GHz'''<br />
File: PointSrcMask_545.png | '''PointSource mask 545 GHz'''<br />
File: PointSrcMask_857.png | '''PointSource mask 857 GHz'''<br />
</gallery><br />
</center><br />
<br />
''' File names '''<br />
The FITS filenames are of the form ''{H|L}FI_SkyMap_fff{-tag}_Nside_R2.nn_{coverage}-{type}.fits'', where ''fff'' are three digits to indicate the Planck frequency band, ''tag'' indicates the single detector or the detset, ''Nside'' is the Healpix Nside of the map, ''coverage'' indicates which part of the mission is covered (full, half mission, survey, year, ...) , and the optional ''type'' indicates the subset of input data used. The table below lists the products by type, with the appropriate unix wildcards that form the full filename.<br />
<br />
{| class="wikitable" align="center" style="text-align"left" border="1" cellpadding="15" cellspacing="20" width=880px<br />
|+ '''HFI FITS filenames'''<br />
|- bgcolor="ffdead"<br />
! Coverage || filename || half-ring filename <br />
|-<br />
| Full chan, full mission ||HFI_SkyMap_???_2048_R2.??_full.fits ||HFI_SkyMap_???_2048_R2.??_full-ringhalf-?.fits<br />
|-<br />
| Full channel, nominal mission ||HFI_SkyMap_???_2048_R2.??_nominal.fits || n/a<br />
|-<br />
| Full channel, single survey || HFI_SkyMap_???_2048_R2.??_survey-?.fits || n/a<br />
|-<br />
| Full channel, single year || HFI_SkyMap_???_2048_R2.??_year-?.fits || n/a<br />
|-<br />
| Full channel, half mission || HFI_SkyMap_???_2048_R2.??_halfmission*-?.fits || n/a<br />
|-<br />
| Det-set, full mission || HFI_SkyMap_???-ds?_2048_R2.??_full.fits || HFI_SkyMap_???-ds?_2048_R2.??_full-ringhalf-?.fits<br />
|-<br />
|Single SWB, full mission || HFI_SkyMap_???-?_2048_R2.??_full.fits || HFI_SkyMap_???-?_2048_R2.??_full-ringhalf-?.fits<br />
|}<br />
<br />
{| class="wikitable" align="center" style="text-align"left" border="1" cellpadding="15" cellspacing="20" width=1000px<br />
|+ '''LFI FITS filenames'''<br />
|- bgcolor="ffdead"<br />
! Coverage || filename || half-ring filename || Comment<br />
|-<br />
| Full channel, full mission ||LFI_SkyMap_???_1024_R2.??_full.fits ||LFI_SkyMap_???_1024_R2.??_full-ringhalf-?.fits || Available also at Nside = 2048<br />
|-<br />
| Full channel, single survey || LFI_SkyMap_???_1024_R2.??_survey-?.fits || n/a || Available also at Nside = 2048<br />
|-<br />
| Full channel, survey combination || LFI_SkyMap_???_1024_R2.??_survey-1-3-5-6-7-8.fits || n/a || n/a<br />
|-<br />
| Full channel, single year || LFI_SkyMap_???_1024_R2.??_year-?.fits || n/a || Available also at Nside = 2048<br />
|-<br />
| Full channel, year combination || LFI_SkyMap_???_1024_R2.??_year?-?.fits || n/a || n/a<br />
|-<br />
| Horn pair, full mission || LFI_SkyMap_???-??-??_1024_R2.??_full.fits || LFI_SkyMap_???_??-??_1024_R2.??_full-ringhalf-?.fits || Available also at Nside = 2048<br />
|-<br />
| Single radiometer, full mission || LFI_SkyMap_???-???_1024_R2.??_full.fits || LFI_SkyMap_???-???_1024_R2.??_full-ringhalf-?.fits || n/a<br />
|}<br />
<br />
<br />
<br />
For the benefit of users who are only looking for the frequency maps with no additional information, we also provide a file combining the 9 frequency maps as separate columns in a single extension. The 9 columns in this file contain the intensity maps ONLY and no other information (hit maps and variance maps) is provided.<br />
<br />
<!---<br />
{| class="wikitable" align="center" style="text-align:center" border="1" cellpadding="3" cellspacing="0" width=500px<br />
|+ '''FITS filenames'''<br />
|- bgcolor="ffdead"<br />
! Frequency || Full channel maps<br />
|-<br />
| '''30GHz''' || {{PLASingleFile|fileType=map|name=LFI_SkyMap_030_1024_R1.10_nominal.fits|link=LFI_SkyMap_030_1024_R1.10_nominal.fits}}<br />
|-<br />
| '''44GHz''' || {{PLASingleFile|fileType=map|name=LFI_SkyMap_044_1024_R1.10_nominal.fits|link=LFI_SkyMap_044_1024_R1.10_nominal.fits}}<br />
|-<br />
| '''70GHz''' || {{PLASingleFile|fileType=map|name=LFI_SkyMap_070_1024_R1.10_nominal.fits|link=LFI_SkyMap_070_1024_R1.10_nominal.fits}}<br />
|-<br />
| '''70GHz''' || {{PLASingleFile|fileType=map|name=LFI_SkyMap_070_2048_R1.10_nominal.fits|link=LFI_SkyMap_070_2048_R1.10_nominal.fits}}<br />
|-<br />
| '''100GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_100_2048_R1.10_nominal.fits|link=HFI_SkyMap_100_2048_R1.10_nominal.fits}}<br />
|-<br />
| '''143GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_143_2048_R1.10_nominal.fits|link=HFI_SkyMap_143_2048_R1.10_nominal.fits}}<br />
|-<br />
| '''217GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_217_2048_R1.10_nominal.fits|link=HFI_SkyMap_217_2048_R1.10_nominal.fits}}<br />
|-<br />
| '''353GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_353_2048_R1.10_nominal.fits|link=HFI_SkyMap_353_2048_R1.10_nominal.fits}}<br />
|-<br />
| '''545GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_545_2048_R1.10_nominal.fits|link=HFI_SkyMap_545_2048_R1.10_nominal.fits}}<br />
|-<br />
| '''857GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_857_2048_R1.10_nominal.fits|link=HFI_SkyMap_857_2048_R1.10_nominal.fits}}<br />
|- bgcolor="ffdead"<br />
! Frequency || Full channel, Zodi-corrected maps<br />
|-<br />
| '''100GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_100_2048_R1.10_nominal_ZodiCorrected.fits|link=HFI_SkyMap_100_2048_R1.10_nominal_ZodiCorrected.fits}} <br />
|-<br />
| '''143GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_143_2048_R1.10_nominal_ZodiCorrected.fits|link=HFI_SkyMap_143_2048_R1.10_nominal_ZodiCorrected.fits}}<br />
|-<br />
| '''217GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_217_2048_R1.10_nominal_ZodiCorrected.fits|link=HFI_SkyMap_217_2048_R1.10_nominal_ZodiCorrected.fits}}<br />
|-<br />
| '''353GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_353_2048_R1.10_nominal_ZodiCorrected.fits|link=HFI_SkyMap_353_2048_R1.10_nominal_ZodiCorrected.fits}}<br />
|-<br />
| '''545GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_545_2048_R1.10_nominal_ZodiCorrected.fits|link=HFI_SkyMap_545_2048_R1.10_nominal_ZodiCorrected.fits}}<br />
|-<br />
| '''857GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_857_2048_R1.10_nominal_ZodiCorrected.fits|link=HFI_SkyMap_857_2048_R1.10_nominal_ZodiCorrected.fits}}<br />
|- bgcolor="ffdead"<br />
! Frequency || Combined frequency maps<br />
|-<br />
| '''All''' || {{PLASingleFile|fileType=file|name=COM_MapSet_I-allFreqs_R1.10_nominal.fits|link=COM_MapSet_I-allFreqs_R1.10_nominal.fits}} <br />
|}<br />
<br />
<br />
{| class="wikitable" align="center" style="text-align:center" border="1" cellpadding="3" cellspacing="0" width=850px<br />
|+ '''FITS filenames'''<br />
|- bgcolor="ffdead"<br />
! Frequency || Survey 1 maps || Survey 2 maps<br />
|-<br />
| '''30GHz''' || {{PLASingleFile|fileType=map|name=LFI_SkyMap_030_1024_R1.10_survey_1.fits|link=LFI_SkyMap_030_1024_R1.10_survey_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=LFI_SkyMap_030_1024_R1.10_survey_2.fits|link=LFI_SkyMap_030_1024_R1.10_survey_2.fits}}<br />
|-<br />
| '''44GHz''' || {{PLASingleFile|fileType=map|name=LFI_SkyMap_044_1024_R1.10_survey_1.fits|link=LFI_SkyMap_044_1024_R1.10_survey_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=LFI_SkyMap_044_1024_R1.10_survey_2.fits|link=LFI_SkyMap_044_1024_R1.10_survey_2.fits}}<br />
|-<br />
| '''70GHz''' || {{PLASingleFile|fileType=map|name=LFI_SkyMap_070_1024_R1.10_survey_1.fits|link=LFI_SkyMap_070_1024_R1.10_survey_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=LFI_SkyMap_070_1024_R1.10_survey_2.fits|link=LFI_SkyMap_070_1024_R1.10_survey_2.fits}}<br />
|-<br />
| '''70GHz''' || {{PLASingleFile|fileType=map|name=LFI_SkyMap_070_2048_R1.10_survey_1.fits|link=LFI_SkyMap_070_2048_R1.10_survey_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=LFI_SkyMap_070_2048_R1.10_survey_2.fits|link=LFI_SkyMap_070_2048_R1.10_survey_2.fits}}<br />
|-<br />
| '''100GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_100_2048_R1.10_survey_1.fits|link=HFI_SkyMap_100_2048_R1.10_survey_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_100_2048_R1.10_survey_2.fits|link=HFI_SkyMap_100_2048_R1.10_survey_2.fits}}<br />
|-<br />
| '''143GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_143_2048_R1.10_survey_1.fits|link=HFI_SkyMap_143_2048_R1.10_survey_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_143_2048_R1.10_survey_2.fits|link=HFI_SkyMap_143_2048_R1.10_survey_2.fits}}<br />
|-<br />
| '''217GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_217_2048_R1.10_survey_1.fits|link=HFI_SkyMap_217_2048_R1.10_survey_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_217_2048_R1.10_survey_2.fits|link=HFI_SkyMap_217_2048_R1.10_survey_2.fits}}<br />
|-<br />
| '''353GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_353_2048_R1.10_survey_1.fits|link=HFI_SkyMap_353_2048_R1.10_survey_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_353_2048_R1.10_survey_2.fits|link=HFI_SkyMap_353_2048_R1.10_survey_2.fits}}<br />
|-<br />
| '''545GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_545_2048_R1.10_survey_1.fits|link=HFI_SkyMap_545_2048_R1.10_survey_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_545_2048_R1.10_survey_2.fits|link=HFI_SkyMap_545_2048_R1.10_survey_2.fits}}<br />
|-<br />
| '''857GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_857_2048_R1.10_survey_1.fits|link=HFI_SkyMap_857_2048_R1.10_survey_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_857_2048_R1.10_survey_2.fits|link=HFI_SkyMap_857_2048_R1.10_survey_2.fits}}<br />
|- bgcolor="ffdead"<br />
! Frequency || Survey 1 Zodi-corrected maps || Survey 2 Zodi-corrected maps<br />
|-<br />
| '''100GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_100_2048_R1.10_survey_1_ZodiCorrected.fits|link=HFI_SkyMap_100_2048_R1.10_survey_1_ZodiCorrected.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_100_2048_R1.10_survey_2_ZodiCorrected.fits|link=HFI_SkyMap_100_2048_R1.10_survey_2_ZodiCorrected.fits}}<br />
|-<br />
| '''143GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_143_2048_R1.10_survey_1_ZodiCorrected.fits|link=HFI_SkyMap_143_2048_R1.10_survey_1_ZodiCorrected.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_143_2048_R1.10_survey_2_ZodiCorrected.fits|link=HFI_SkyMap_143_2048_R1.10_survey_2_ZodiCorrected.fits}}<br />
|-<br />
| '''217GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_217_2048_R1.10_survey_1_ZodiCorrected.fits|link=HFI_SkyMap_217_2048_R1.10_survey_1_ZodiCorrected.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_217_2048_R1.10_survey_2_ZodiCorrected.fits|link=HFI_SkyMap_217_2048_R1.10_survey_2_ZodiCorrected.fits}}<br />
|-<br />
| '''353GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_353_2048_R1.10_survey_1_ZodiCorrected.fits|link=HFI_SkyMap_353_2048_R1.10_survey_1_ZodiCorrected.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_353_2048_R1.10_survey_2_ZodiCorrected.fits|link=HFI_SkyMap_353_2048_R1.10_survey_2_ZodiCorrected.fits}}<br />
|-<br />
| '''545GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_545_2048_R1.10_survey_1_ZodiCorrected.fits|link=HFI_SkyMap_545_2048_R1.10_survey_1_ZodiCorrected.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_545_2048_R1.10_survey_2_ZodiCorrected.fits|link=HFI_SkyMap_545_2048_R1.10_survey_2_ZodiCorrected.fits}}<br />
|-<br />
| '''857GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_857_2048_R1.10_survey_1_ZodiCorrected.fits|link=HFI_SkyMap_857_2048_R1.10_survey_1_ZodiCorrected.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_857_2048_R1.10_survey_2_ZodiCorrected.fits|link=HFI_SkyMap_857_2048_R1.10_survey_2_ZodiCorrected.fits}}<br />
|- bgcolor="ffdead"<br />
! Frequency || Half-ring 1 maps ||Half-ring 2 maps<br />
|-<br />
| '''30GHz''' || {{PLASingleFile|fileType=map|name=LFI_SkyMap_030_1024_R1.10_nominal_ringhalf_1.fits|link=LFI_SkyMap_030_1024_R1.10_nominal_ringhalf_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=LFI_SkyMap_030_1024_R1.10_nominal_ringhalf_2.fits|link=LFI_SkyMap_030_1024_R1.10_nominal_ringhalf_2.fits}}<br />
|-<br />
| '''44GHz''' || {{PLASingleFile|fileType=map|name=LFI_SkyMap_044_1024_R1.10_nominal_ringhalf_1.fits|link=LFI_SkyMap_044_1024_R1.10_nominal_ringhalf_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=LFI_SkyMap_044_1024_R1.10_nominal_ringhalf_2.fits|link=LFI_SkyMap_044_1024_R1.10_nominal_ringhalf_2.fits}}<br />
|-<br />
| '''70GHz''' || {{PLASingleFile|fileType=map|name=LFI_SkyMap_070_1024_R1.10_nominal_ringhalf_1.fits|link=LFI_SkyMap_070_1024_R1.10_nominal_ringhalf_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=LFI_SkyMap_070_1024_R1.10_nominal_ringhalf_2.fits|link=LFI_SkyMap_070_1024_R1.10_nominal_ringhalf_2.fits}}<br />
|-<br />
| '''70GHz''' || {{PLASingleFile|fileType=map|name=LFI_SkyMap_070_2048_R1.10_nominal_ringhalf_1.fits|link=LFI_SkyMap_070_2048_R1.10_nominal_ringhalf_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=LFI_SkyMap_070_2048_R1.10_nominal_ringhalf_2.fits|link=LFI_SkyMap_070_2048_R1.10_nominal_ringhalf_2.fits}}<br />
|-<br />
| '''100GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_100_2048_R1.10_nominal_ringhalf_1.fits|link=HFI_SkyMap_100_2048_R1.10_nominal_ringhalf_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_100_2048_R1.10_nominal_ringhalf_2.fits|link=HFI_SkyMap_100_2048_R1.10_nominal_ringhalf_2.fits}}<br />
|-<br />
| '''143GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_143_2048_R1.10_nominal_ringhalf_1.fits|link=HFI_SkyMap_143_2048_R1.10_nominal_ringhalf_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_143_2048_R1.10_nominal_ringhalf_2.fits|link=HFI_SkyMap_143_2048_R1.10_nominal_ringhalf_2.fits}}<br />
|-<br />
| '''217GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_217_2048_R1.10_nominal_ringhalf_1.fits|link=HFI_SkyMap_217_2048_R1.10_nominal_ringhalf_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_217_2048_R1.10_nominal_ringhalf_2.fits|link=HFI_SkyMap_217_2048_R1.10_nominal_ringhalf_2.fits}}<br />
|-<br />
| '''353GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_353_2048_R1.10_nominal_ringhalf_1.fits|link=HFI_SkyMap_353_2048_R1.10_nominal_ringhalf_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_353_2048_R1.10_nominal_ringhalf_2.fits|link=HFI_SkyMap_353_2048_R1.10_nominal_ringhalf_2.fits}}<br />
|-<br />
| '''545GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_545_2048_R1.10_nominal_ringhalf_1.fits|link=HFI_SkyMap_545_2048_R1.10_nominal_ringhalf_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_545_2048_R1.10_nominal_ringhalf_2.fits|link=HFI_SkyMap_545_2048_R1.10_nominal_ringhalf_2.fits}}<br />
|-<br />
| '''857GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_857_2048_R1.10_nominal_ringhalf_1.fits|link=HFI_SkyMap_857_2048_R1.10_nominal_ringhalf_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_857_2048_R1.10_nominal_ringhalf_2.fits|link=HFI_SkyMap_857_2048_R1.10_nominal_ringhalf_2.fits}}<br />
|}<br />
---><br />
<br />
''' FITS file structure '''<br />
<br />
The FITS files for the sky maps contain a minimal primary header with no data, and a ''BINTABLE'' extension (EXTENSION 1, EXTNAME = ''FREQ-MAP'') containing the data. The structure is shows schematically in the figure below. The ''FREQ-MAP'' extension contains a 3- or a 10-column table that contain the signal, hit-count and variance maps, all in Healpix format. The 3-column case is for intensity only maps, the 10-column case is for polarisation. The number of rows is the number of map pixels, which is Npix = 12 <math>N_{side}</math><sup>2</sup> for Healpix maps, where <math>N_{side}</math> = 1024 or 2048 for most the maps presented in this chapter.<br />
<br />
[[File:FITS_FreqMap.png | 550px | center | thumb | '''FITS file structure''']]<br />
<br />
Note that file sizes are ~0.6 GB for I-only maps and ~1.9 GB for I,Q,U maps at <math>N_{side}</math> 2048 and ~0.14 GB for I-only maps and ~0.45 GB for I,Q,U maps at <math>N_{side}</math> 1024 .<br />
<br />
Keywords indicate the coordinate system (GALACTIC), the Healpix ordering scheme (NESTED), the units (K_cmb or MJy/sr) of each column, and of course the frequency channel (FREQ). Where polarisation Q and U maps are provided, the ''COSMO'' polarisation convention (used in HEALPIX) is adopted, and it is specified in the ''POLCCONV'' keyword (see [[Sky_temperature_maps#Polarization_convention_used_in_the_Planck_project|this section]]. The COMMENT fields give a one-line summary of the product, and some other information useful for traceability within the DPCs. The original filename is also given in the ''FILENAME'' keyword. The ''BAD_DATA'' keyword gives the value used by Healpix to indicate pixels for which no signal is present (these will also have a hit-count value of 0). The main parameters are summarised below:<br />
<br />
<br />
{| border="1" cellpadding="3" cellspacing="0" align="center" style="text-align:left" width=800px<br />
|+ '''Sky map file data structure'''<br />
|- bgcolor="ffdead" <br />
!colspan="4" | 1. EXTNAME = 'FREQ-MAP' : Data columns<br />
|- bgcolor="ffdead" <br />
! Column Name || Data Type || Units || Description<br />
|-<br />
|I_STOKES || Real*4 || K_cmb or MJy/sr || The Stokes I map<br />
|-<br />
|Q_STOKES || Real*4 || K_cmb or MJy/sr || The Stokes Q map (optional)<br />
|-<br />
|U_STOKES || Real*4 || K_cmb or MJy/sr || The Stokes U map (optional)<br />
|-<br />
|HITS || Int*4 || none || The hit-count map<br />
|-<br />
|II_COV || Real*4 || K_cmb<sup>2</sup> or (MJy/sr)<sup>2</sup> || The II variance map<br />
|-<br />
|IQ_COV || Real*4 || K_cmb<sup>2</sup> or (MJy/sr)<sup>2</sup> || The IQ variance map (optional)<br />
|-<br />
|IU_COV || Real*4 || K_cmb<sup>2</sup> or (MJy/sr)<sup>2</sup> || The IQ variance map (optional)<br />
|-<br />
|QQ_COV || Real*4 || K_cmb<sup>2</sup> or (MJy/sr)<sup>2</sup> || The QQ variance map (optional)<br />
|-<br />
|QU_COV || Real*4 || K_cmb<sup>2</sup> or (MJy/sr)<sup>2</sup> || The QU variance map (optional)<br />
|-<br />
|UU_COV || Real*4 || K_cmb<sup>2</sup> or (MJy/sr)<sup>2</sup> || The UU variance map (optional)<br />
|-<br />
|- bgcolor="ffdead" <br />
! Keyword || Data Type || Value || Description<br />
|-<br />
|PIXTYPE || string || HEALPIX ||<br />
|-<br />
|COORDSYS || string || GALACTIC ||Coordinate system <br />
|-<br />
|ORDERING || string || NESTED || Healpix ordering<br />
|-<br />
|POLCCONV || String || COSMO || Polarization convention<br />
|-<br />
|NSIDE || Int || 1024 or 2048 || Healpix <math>N_{side}</math> <br />
|-<br />
|FIRSTPIX || Int*4 || 0 || First pixel number<br />
|-<br />
|LASTPIX || Int*4 || 12 <math>N_{side}</math><sup>2</sup> – 1 || Last pixel number<br />
|-<br />
|FREQ || string || nnn || The frequency channel <br />
|}<br />
<br />
<br />
The same structure applies to all ''SkyMap'' products, independent of whether they are full channel, survey of half-ring. The distinction between the types of maps is present in the FITS filename (and in the traceability comment fields).<br />
<br />
'''Polarization convention used in the Planck project'''<br />
<br />
The Planck collaboration used the COSMO convention for the polarization angle (as usually used in space based CMB missions), whereas other astronomical fields usually use the IAU convention. In the following document we report the difference between these two conventions, and the consequence if it is NOT taken into account correctly in the analysis.<br />
<br />
[[File:conventions.png|thumb|center|400px|'''Figure 1. COSMO convention (left) and IAU convention (right). The versor <math>\hat{z}</math> points outwards the pointing direction in COSMO, and inwards in IAU. The bottom panel refers to the plane tangent to the sphere.''']]<br />
<br />
Changing the orientation convention is equivalent to a transformation <math>\psi'=\pi-\psi</math> of the polarization angle (Figure 1). The consequence of this transformation is the inversion of the Stokes parameter <math>U</math>.<br />
The components of the polarization tensor in the helicity basis <math>\epsilon^{\pm}=1/\sqrt{2}(\hat{x}\pm i\hat{y})</math> are:<br />
<br />
<math><br />
(Q+iU)(\hat{n}) = \sum _{\ell m}a_{2,lm}{}_{2}Y_{\ell }^{m}(\hat{n})<br />
\\(Q-iU)(\hat{n}) = \sum _{\ell m}a_{-2,lm}{}_{2}Y_{\ell }^{m}(\hat{n})<br />
</math><br />
<br />
where <math>{}_{2}Y_{\ell }^{m}(\hat{n})</math> are the spin weighted spherical harmonic functions.<br />
The <math>E</math> and <math>B</math> modes can be defined as:<br />
<math><br />
E(\hat{n}) = \sum_{\ell m}a_{E,\ell m}Y_{\ell }^{m}(\hat{n})<br />
\\B(\hat{n}) = \sum_{\ell m}a_{B,\ell m}Y_{\ell }^{m}(\hat{n})<br />
</math><br />
<br />
where the coefficients <math>a_{E,\ell m}</math> and <math>a_{B,\ell m}</math> are derived from linear combinations of the <math>a_{2,\ell m}</math> , <math>a_{-2,\ell m}</math> defined implicitly in the first equation (<math>Q\pm iU</math>).<br />
<br />
[[File:test_gradient.jpg|thumb|center|400px|]]<br />
[[File:test_curl.jpg|thumb|center|400px|'''Figure 2. Error on Planck-LFI 70 GHz <math>EE</math> (top) and <math>BB</math> (bottom) spectra, in case of wrong choice of the coordinate system convention (IAU instead of COSMO).''']]<br />
<br />
The effect of the sign inversion of <math>U</math> on the polarization spectra is a non trivial mixing of <math>E</math> and <math>B</math> modes. <br />
<br />
An example of the typical error on <math>EE</math> and <math>BB</math> auto-spectra in case of a wrong choice of the polarization basis is shown in Figure 2.<br />
<br />
BE CAREFUL about the polarization convention you are using. If the IAU convention is used in computing the power spectra, the sign of the <math>U</math> component of the Planck maps must be inverted before computing <math>E</math> and <math>B</math> modes.<br />
<br />
''' Note on the convention used by the Planck Catalogue of Compact Sources (PCCS) '''<br />
For continuity with other compact sources catolgues, the Catalogue of Compact Sources provided by Planck follows the IAU convention, and the polarization angles are defined on an interval of [-90&deg;,90&deg;]. To switch to the COSMO convention, the polarization angles listed in the catalogue have to be shifted by 90&deg; and multiplied by -1.<br />
<br />
== References ==<br />
<References /><br />
<br />
</div><br />
</div><br />
<br />
<div class="toccolours mw-collapsible mw-collapsed" style="background-color: #EEE8AA;width:80%" ><br />
'''2013 Sky temperature maps'''<br />
<br />
<div class="mw-collapsible-content"><br />
<br />
'''General description'''<br />
<br />
<br />
Sky maps give the best estimate of the intensity of the signal from the sky after removal, as far as possible, of known systematic effects and of the dipole signals induced by the motion of the solar system in the CMB and of the Planck satellite in the solar system. Sky maps are provided for the nominal Planck mission and also, separately, for the first two single surveys, the third one being covered only for a small part during the nominal mission.The details of the start and end times of each are given in [[HFIpreprocessingstatics | this table]]. As a secondary product, maps with estimates of the Zodiacal light and Far-Side-Lobes contribution removed are also provided. <br />
<br />
For characterization purposes, are also provided maps covering the nominal survey but each one using only half of the available data. These are the ''ringhalf_{1|2}'' maps, which are built using the first and second half of the stable pointing part in each pointing period. These maps are used extensively to investigate the (high frequency) noise properties the maps themselves and of other products described elsewhere (see e.g., the [[HFI-Validation | data validation]] section).<br />
<br />
To help in further processing, there are also masks of the Galactic Plane and of point sources, each provided for several different depths.<br />
<br />
All sky maps are in Healpix format, with Nside of 2048 for HFI and of 1024 for LFI (note that the LFI 70 GHz has been delivered also at Nside of 2048 to be directly comparable with HFI maps), in Galactic coordinates, and Nested ordering. The signal is given in units of K<sub>cmb</sub> for 30-353 GHz, and of MJy/sr (for a constant $\nu F_\nu$ energy distribution ) for 545 and 857 GHz. Each sky map is packaged into a ''BINTABLE'' extension of a FITS file together with a hit-count map (or hit map, for short, giving the number of observation samples that are cumulated in a pixel, all detectors combined) and a variance map (determined from the half-ring maps), and additional information is given in the FITS file header. The structure of the FITS file is given in the [[#Format | FITS file structure]] section below.<br />
<br />
<br />
'''Types of maps '''<br />
<br />
; Full channel maps<br />
: Full channel maps are built using all the valid detectors of a frequency channel and cover the nominal mission. For HFI, the 143-8 and 545-3 bolometers are rejected entirely as they are seriously affected by RTS noise. The maps are displayed in the figures below. The range is the same from 30 - 143 GHz in order to show the CMB at the same level. At higher frequencies the range is increased in order to keep the Galactic Plane from invading the whole sky.<br />
<br />
<center><br />
<gallery style="padding:0 0 0 0;" perrow=3 widths=260px heights=160px> <br />
File: SkyMap30.png| '''Nominal mission, 30 GHz'''<br />
File: SkyMap44.png | '''Nominal mission, 44 GHz'''<br />
File: SkyMap70.png | '''Nominal mission, 70 GHz'''<br />
File: SkyMap100.png | '''Nominal mission, 100 GHz'''<br />
File: SkyMap143.png | '''Nominal mission, 143 GHz'''<br />
File: SkyMap217.png | '''Nominal mission, 217 GHz'''<br />
File: SkyMap353.png | '''Nominal mission, 353 GHz'''<br />
File: SkyMap545.png | '''Nominal mission, 545 GHz'''<br />
File: SkyMap857.png | '''Nominal mission, 857 GHz'''<br />
</gallery><br />
</center><br />
<br />
; Single survey maps <br />
: Single survey maps are built using all valid detectors of a frequency channel; they cover separately the different sky surveys. The surveys are defined as the times over which the satellite spin axis rotates but 180 degrees, which, due to the position of the detectors in the focal plane does not cover the full sky, but a fraction between ~80 and 90% depending on detector position.<br />
<br />
; Detector set or detector pairs maps<br />
: These are maps built from a subset of the detectors in a frequency channel, typically our of two PSB pairs (i.e., four poloarisation-sensitive bolometers with different orientation on the sky), for HFI in order to extract a single temperature map. While none of these maps are part of the first Planck data release, the concept of ''detset'' is used, and thus it is worth mentioning it here. In particular, information by detector set is available at the [[Frequency_maps_angular_power_spectra | sky power spectrum]] level and in the [[The RIMO | RIMO]].<br />
<br />
; Half-ring maps<br />
: Half-ring maps are built using only the first or the second half of the stable pointing period data. There are thus two half-ring maps per frequency channel named ''ringhalf_1'' and ''ringhalf_2'' respectively. These maps are built for characterization purposes in order to perform null tests. In particular, the difference between the two half-ring maps at a given frequency give a good estimate of the high frequency noise in the data (albeit biased low by ~0.5% for the HFI channels due to specifics of the TOI processing).<br />
<br />
; Masks<br />
: Masks are provided of the Galactic Plane and of the point sources. For the Galactic Plane, eight masks are given covering different fractions of the sky, and for the points sources two masks are given, at the 5 and 10 sigma level, for each Planck HFI frequency channel. These are generic masks, specific masks applicable to other products are delivered with the products themselves.<br />
<br />
''' Caveats and known issues'''<br />
<br />
The primary limitation of the HFI maps are<br />
* the absence of correction of the ADC non-linearities,<br />
* the far-side lobe contribution is not accounted for in the processing and in the calibration,<br />
* the dipole removal is based on the non-relativistic approximation which leaves a weak quadrupole component in the map.<br />
And thus the overall calibration accuracy is at the 0.2% level in 100-217 GHz channels<br />
<br />
The LFI 70 GHz maps at Nside=2048 should be considered as additional product, the default are the LFI maps at Nside=1024. No effective beam at Nside=2048 is provided, only at Nside=1024, for this reason the use of the effective beam with maps at Nside 2048 is discouraged.<br />
<br />
''' Map zero-level '''<br />
<br />
For the 100 to 857 GHz maps, the zero levels are set to their optimal levels for Galactic and CIB studies. A procedure for adjusting them to astrophysical values is given in the HFI Calibration paper {{PlanckPapers|planck2013-p03b}}.<br />
<br />
For the 30, 44 and 70 GHz, maps are corrected for zero level monopole by applying an offset correction, see LFI Calibration paper {{PlanckPapers|planck2013-p02b}} section 3.4 "Setting the zero levels in the maps". Note that the offset applied is indicated in the header as a comment keyword.<br />
<br />
''' The Zodiacal light and the Far-Side Lobes '''<br />
<br />
The figures below show the modeled Zodiacal light and Far Side Lobes projected onto the maps; they are simply the difference between the ''main product'' and the ''ZodiCorrected'' maps for the nominal mission. The units are given in the figures. The ''heat'' color table has been used in place of the standard Planck for clarity reasons. <br />
<center><br />
<gallery perrow=3 widths=260px heights=170px><br />
File: ZodiRes100.png | '''zodi/FSL rediduals - 100 GHz'''<br />
File: ZodiRes143.png | '''zodi/FSL rediduals - 143 GHz''' <br />
File: ZodiRes217.png | '''zodi/FSL rediduals - 217 GHz'''<br />
File: ZodiRes353.png | '''zodi/FSL rediduals - 353 GHz'''<br />
File: ZodiRes545.png | '''zodi/FSL rediduals - 545 GHz'''<br />
File: ZodiRes857.png | '''zodi/FSL rediduals - 857 GHz'''<br />
</gallery><br />
</center><br />
The effects of the FSLs are seen most clearly at the highest frequencies, as structures roughly symmetric about the center of the image, which corresponds to the location of the Galactic Centre, which is in turn the source of most of the radiation that is scattered into the FSLs.<br />
<br />
''' Artifacts near caustics of the scanning strategy '''<br />
<br />
The [[Survey scanning and performance|scanning strategy]] is such that regions around the Ecliptic poles are surveyed very deeply and compared to the average, and the transition from the nominal depth to the high depth, as shows on hit-count maps is very rapid, namely a few pixels, for a contrast of ~30. These transitions, or caustics in the maps, occur at different positions on the sky for different detectors, as the positions depend on their location in the focal plane of the instrument. As a result, when data from different detectors are combined to build a full channel map, the the weights of different detectors in the mix changes rapidly across the caustic, and given the remaining errors in the relative calibration of the detectors, a visible effect can be introduced in the maps, especially when the SNR is very high, i.e. at the highest frequencies and near bright regions like the Galactic Plane. Some examples are shown below.<br />
<br />
<center><br />
<gallery perrow=3 heights=260px widths=260pix ><br />
File: causta857.png | '''857 GHz intensity map around (272.5, -27)'''<br />
File: caustb857.png | '''857 GHz intensity map around (264.5, -37.5)'''<br />
File: caustc857.png | '''857 GHz intensity map around (98.5, 43)'''<br />
File: hita857.png | '''857 GHz hit count map around (272.5, -27)'''<br />
File: hitb857.png | '''857 GHz hit count map around (264.5, -37.5)'''<br />
File: hitc857.png | '''857 GHz hit count map around (98.5, 43)'''<br />
</gallery><br />
</center><br />
<br />
'''Production process'''<br />
<br />
<br />
Sky maps are produced by combining appropriately the data of all working detectors in a frequency channel over some period of the mission. They give the best estimate of the signal from the sky (unpolarised) after removal, as far as possible, of known systematic effects and of the dipole signals induced by the motion of the solar system in the CMB and of the Planck satellite in the solar system. In particular, they include the Zodiacal light emission (Zodi for short) and also the scattering from the far-side lobes of the beams (FSL). More on this below.<br />
<br />
''' HFI processing '''<br />
<br />
The inputs to the mapmaking are TOIs of signal that have been cleaned (as far as possible) of instrumental effects and calibrated in absorbed watts. While the processing involved is described in detail in the [[TOI processing|TOI processing]] section, we give a very brief summary here for convenience. That pipeline performs the following operations:<br />
<br />
; demodulation: this is performed around a variable level which is determined from the valid input data (a validity flag from a previous version of the processing is used for this purpose), and the data are converted to engineering units (V) using known conversion coefficients.<br />
; despiking: using the demodulated data converted to V (by the transfer function) the glitches are identified and fitted with templates. A glitch flag is produced that identifies the strongest part of the glitches, and a timeline of glitch tails is produced from the template fits, and subtracted from the demodulated timeline from step 1. Finally, the flagged ranges are replaced with data from an average over the pointing period (TBC)<br />
; dark template removal: the two dark bolometers are demodulated and despiked as above; the resulting timelines are then smoothed and used as an indicator of the overall temperature variations of the bolometer plate. Where the variations are consistent with each other, they are combined and removed from the bolometer signal timelines using appropriate coupling coefficients. The few percent of the data where they are not consistent are flagged on the timelines.<br />
; conversion to absorbed power: the timeline is converted to watts of absorbed power using the bolometer function. This includes a non-linearity correction; removal of the 4K cooler lines: the electromagnetic interference of the 4K cooler with the bolometer readout wires induces some sharp lines in the signal power spectra at frequencies of the 4K cooler's fundamental and its multiples, folded by the signal modulations. Fourier coefficients of the relevant lines are determined on a per-ring basis, and then removed from the data. The quality of the removal depends on the bolometer.<br />
; deconvolution by the time transfer function: this is done to correct for the non-instantaneous time response of the bolometers. The function itself is modeled using 4 parameters which are adjusted primarily on the planet data and also from comparisons of the northward and southward scans of the Galactic Plane. It is then removed using Fourier techniques, which has the side-effect of increasing the noise at high frequencies.<br />
; jump correction: removes some (relatively rare: 0.3 jumps per bolometer per pointing period, on average) jumps in the signal baseline. The jumps are detected characterized on smoothed TOIs, and corrected by adding a constant to part of the signal timeline. The origin of the jumps is not known.<br />
<br />
The results of this processing are a timeline of signal (in absorbed watts) and a ''valid data'' flag timeline for each of the 50 valid bolometers processed; these timelines contain the full sky signal, i.e., including the solar and orbital dipoles, the Zodiacal light, and contributions from the Far-Side lobes. The dipoles are necessary for the flux calibration and are removed at the mapmaking stage. The remaining two bolometers (143-8 and 535-3) show semi-random jumps in the signal level, typically jumping over 2-5 different ''pseudo-baseline'' levels, a behavior known as ''Random Telegraphic Signal'', so that these are commonly called the RTS bolometers. Finally, ring-level statistics of different types (mean, median, rms, kurtosis, etc.) are determined on a per-ring basis for all timelines, and a selection based on these statistics is used to discard anomalous rings, which are recorded in a ring-level flag for each valid bolometer timeline (see the [[TOI_processing#Discarded_rings| Discarded rings]] section). <br />
<br />
Throughout this processing, bright planets (Mars, Jupiter, Saturn, Uranus) and bright asteroids are masked in the timeline in order to avoid ringing effects in the processing. Since they move on the sky, the portion of the sky masked during one survey is observed during one, and no hole is left in the final map. In parallel, the planet data are processed in a similar way, but with different parameters for the despiking step, and without the final jump correction step. These results are processed separately to determine the beam shapes and the focal plane geometry.<br />
<br />
The pointing is determined starting from the AHF produced by MOC, which gives the direction and orientation of the LOS of a fiducial position in the focal plane at frequencies of 8Hz during stable pointing and 4 Hz during maneuvers (TBC for details, reference). This is interpolated to the times of data observation (ref to method), corrected for the wobble and other time-dependent offsets determined from the observed positions of a large number of sources around the sky, and finally converted to the LOS of each detector using the quaternions in the IMO (which are determined from observations of bright planets - see the [[Detector_pointing]] section). <br />
<br />
The mapmaking and calibration process is described in detail in the [[Map-making_LFI | Map-making]] section, where detailed references are found. In brief it consists of:<br />
<br />
; binning the TOI data onto ''rings'' : Healpix rings (HPRs) are used here, each ring containing the combined data of one pointing period. <br />
; flux calibration : at 100-353 GHz, the flux calibration factors are determined for each pointing period (or ring) from the solar-motion dipole, using the WMAP dipole as the reference, and after removal of the dipole signal induced by the motion of the Planck satellite in the solar system. This gain by ring is smoothed with a window of width 50 rings, which reveals an apparent variation of ~1-2% on a scale of 100s to 1000s of rings for the 100-217 GHz channels, and is applied. At 353GHz, where the solar motion dipole is weaker compared to the signal, no gain variation is detected (within the uncertainties), and a single fixed gain is applied to all rings. At 545 and 857 GHz the gain is determined from the observation of Uranus and Neptune (but not Jupiter which is too bright) and comparison to recent models made explicitly for this mission. A single gain is applied to all rings at these frequencies.<br />
; destriping : in order to remove low-frequency noise, an offset per ring is determined by minimizing the differences between HPRs at their crossings, and removed.<br />
; projection onto the map : the offset-corrected and flux-calibrated HPRs are projected onto Healpix maps, with the data of each bolometer weighted by a factor of 1/NET of that bolometer, and accounting for the slight different band transmission profiles of the bolometers in each band. <br />
<br />
These maps provide the main mission products. A second, reduced, set of maps, cleaned of the Zodiacal emission of the FSL leakage is also produced for the nominal mission and the two single surveys, but not for the half-rings (since the contribution would be the same for the two halves of each ring). For this purpose, the the Zodiacal emission and the FSL contamination, which are not fixed on the sky, are modeled separately at HPR-level, and subtracted from the signal HPR before projecting them onto the maps. <br />
<br />
Together with signal maps, hit count and variance maps are also produced. The hit maps give the (integer) number of valid TOI-level samples that contribute to the signal of each pixel. All valid samples are counted in the same way, i.e., there is no weighting factor applied. The variance maps project the white noise estimate, provided by the NETs, in the sky domain.<br />
<br />
''' LFI processing '''<br />
<br />
LFI maps were constructed with the Madam map-making code, version 3.7.4. The code is based on generalized destriping technique, where the correlated noise component is modeled as a sequence of constant offset, called baselines. A noise filter was used to constrain the baseline solution allowing the use of 1 second baselines.<br />
<br />
Radiometers were combined according to the horn-uniform weighting scheme to minimize systematics. The used weights are listed in [[Map-making LFI#Map-making|Map-making]]. The flagged samples were excluded from the analysis by setting their weights to $C_{w}^{-1}$ = 0. The galaxy region was masked out in the destriping phase, to reduce error arising from strong signal gradients. The polarization component was included in the analysis, although only the temperature maps are released. <br />
<br />
A detailed description of the map-making procedure is given in {{PlanckPapers|planck2013-p02}} and in section [[Map-making LFI#Map-making|Map-making]].<br />
<br />
'''Inputs'''<br />
<br />
<br />
''' HFI inputs '''<br />
<br />
* The cleaned TOIs of signal of each detector, together with their flags, produced by the [[TOI processing|TOI processing]] pipeline<br />
* The TOIs of pointing (quaternions), described in [[Detector_pointing]]<br />
* Bolometer-level characterization data, from the DPC's internal IMO (not distributed)<br />
* Planck orbit data used to compute and remove the earth dipole<br />
* WMAP solar dipole information used to calibrate the CMB channels<br />
* Planet models used to calibrate the Galactic channels.<br />
<br />
''' LFI inputs '''<br />
<br />
The Madam map-maker takes as an input:<br />
<br />
* The calibrated timelines (for details see [[TOI processing LFI|TOI Processing]])<br />
* The detector pointings (for details see [[Detector pointing|Detector pointing]])<br />
* The noise information in the form of three-parameter (white noise level ($\sigma$), slope, and knee frequency ($f_\mathrm{knee}$)) noise model (for details see [[The RIMO|RIMO]])<br />
<br />
'''Related products'''<br />
<br />
<br />
''' Masks '''<br />
<br />
Masks are provided of<br />
<br />
; the point sources<br />
: 15 masks are provided, three for the LFI (one mask for each frequency masking at the 4<math>\sigma</math> level) and 12 for the HFI (two masks for each frequency at the 5 and 10<math>\sigma</math> levels. For the HFI the masks can be used as they are, for the LFI they need to be downgraded to Nside=1024 except for the 70 GHz channel at Nside=2048 which does not need to be downgraded.<br />
<br />
; the Galactic Plane<br />
: 8 masks are provided giving 20, 40, 60, 70, 80, 90, 97, and 99% sky coverage in two different files, at Nside=2048. For the HFI they can be used as they are, for the LFI they need to be downgraded at Nside=1024 (note that if using the 70 GHZ at Nside=2048 no downgraded is needed)<br />
<br />
<br />
The masks are binary, in GALACTIC coordinates, and NESTED ordering. The table below give the filenames. <br />
<br />
<br />
{| class="wikitable" align="center" style="text-align:center" border="1" cellpadding="5" cellspacing="0" <br />
|+ '''FITS filenames for masks'''<br />
|-bgcolor="ffdead"<br />
! Frequency || LFI Point Source masks<br />
|-<br />
| '''30GHz''' || {{PLASingleFile|fileType=map|name=LFI_MASK_030-ps_2048_R1.00.fits|link=LFI_MASK_030-ps_2048_R1.00.fits}}<br />
|-<br />
| '''44GHz''' || {{PLASingleFile|fileType=map|name=LFI_MASK_044-ps_2048_R1.00.fits|link=LFI_MASK_044-ps_2048_R1.00.fits}}<br />
|-<br />
| '''70GHz''' || {{PLASingleFile|fileType=map|name=LFI_MASK_070-ps_2048_R1.00.fits|link=LFI_MASK_070-ps_2048_R1.00.fits}}<br />
|- bgcolor="ffdead"<br />
! colspan="2" | HFI Point Source masks<br />
|-<br />
| colspan="2" | {{PLASingleFile|fileType=map|name=HFI_Mask_PointSrc_2048_R1.10.fits|link=HFI_Mask_PointSrc_2048_R1.10.fits}}<br />
|- bgcolor="ffdead"<br />
! colspan="2" | Galactic Plane masks<br />
|-<br />
| colspan="2" | {{PLASingleFile|fileType=map|name=HFI_Mask_GalPlane_2048_R1.10.fits|link=HFI_Mask_GalPlane_2048_R1.10.fits}} <br />
|}<br />
<br />
<br />
The masks are shows below in a single figure. While this is quite clear for the Galactic Plane masks, it is less so for the point source masks, but it does give a clear perspective on how the latter are distributed over the sky.<br />
<br />
<center><br />
<gallery perrow=2 widths=300px heights=185px ><br />
File: HFI_GalPlaneMask.png | '''Galactic Plane masks'''<br />
File: HFI_PointSrcMask.png | '''PointSource masks'''<br />
</gallery><br />
</center><br />
<br />
''' File names '''<br />
<br />
<br />
The FITS filenames are of the form ''{H|L}FI_SkyMap_fff_nnnn_R1.nn_{coverage}_{type}.fits'', where ''fff'' are three digits to indicate the Planck frequency band, and ''nnnn'' is the Healpix Nside of the map, ''coverage'' indicates which part of the mission is covered, and the optional ''type'' indicates the subset of input data used. A full list of products, with links to them in the Archive, is given in the tables below.<br />
<br />
For the benefit of users who are only looking for the frequency maps with no additional information, we also provide a file combining the 9 frequency maps as separate columns in a single extension. The 9 columns in this file contain the intensity maps ONLY and no other information (hit maps and variance maps) is provided.<br />
<br />
{| class="wikitable" align="center" style="text-align:center" border="1" cellpadding="5" cellspacing="0" width=500px<br />
|+ '''FITS filenames'''<br />
|- bgcolor="ffdead"<br />
! Frequency || Full channel maps<br />
|-<br />
| '''30GHz''' || {{PLASingleFile|fileType=map|name=LFI_SkyMap_030_1024_R1.10_nominal.fits|link=LFI_SkyMap_030_1024_R1.10_nominal.fits}}<br />
|-<br />
| '''44GHz''' || {{PLASingleFile|fileType=map|name=LFI_SkyMap_044_1024_R1.10_nominal.fits|link=LFI_SkyMap_044_1024_R1.10_nominal.fits}}<br />
|-<br />
| '''70GHz''' || {{PLASingleFile|fileType=map|name=LFI_SkyMap_070_1024_R1.10_nominal.fits|link=LFI_SkyMap_070_1024_R1.10_nominal.fits}}<br />
|-<br />
| '''70GHz''' || {{PLASingleFile|fileType=map|name=LFI_SkyMap_070_2048_R1.10_nominal.fits|link=LFI_SkyMap_070_2048_R1.10_nominal.fits}}<br />
|-<br />
| '''100GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_100_2048_R1.10_nominal.fits|link=HFI_SkyMap_100_2048_R1.10_nominal.fits}}<br />
|-<br />
| '''143GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_143_2048_R1.10_nominal.fits|link=HFI_SkyMap_143_2048_R1.10_nominal.fits}}<br />
|-<br />
| '''217GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_217_2048_R1.10_nominal.fits|link=HFI_SkyMap_217_2048_R1.10_nominal.fits}}<br />
|-<br />
| '''353GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_353_2048_R1.10_nominal.fits|link=HFI_SkyMap_353_2048_R1.10_nominal.fits}}<br />
|-<br />
| '''545GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_545_2048_R1.10_nominal.fits|link=HFI_SkyMap_545_2048_R1.10_nominal.fits}}<br />
|-<br />
| '''857GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_857_2048_R1.10_nominal.fits|link=HFI_SkyMap_857_2048_R1.10_nominal.fits}}<br />
|- bgcolor="ffdead"<br />
! Frequency || Full channel, Zodi-corrected maps<br />
|-<br />
| '''100GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_100_2048_R1.10_nominal_ZodiCorrected.fits|link=HFI_SkyMap_100_2048_R1.10_nominal_ZodiCorrected.fits}} <br />
|-<br />
| '''143GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_143_2048_R1.10_nominal_ZodiCorrected.fits|link=HFI_SkyMap_143_2048_R1.10_nominal_ZodiCorrected.fits}}<br />
|-<br />
| '''217GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_217_2048_R1.10_nominal_ZodiCorrected.fits|link=HFI_SkyMap_217_2048_R1.10_nominal_ZodiCorrected.fits}}<br />
|-<br />
| '''353GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_353_2048_R1.10_nominal_ZodiCorrected.fits|link=HFI_SkyMap_353_2048_R1.10_nominal_ZodiCorrected.fits}}<br />
|-<br />
| '''545GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_545_2048_R1.10_nominal_ZodiCorrected.fits|link=HFI_SkyMap_545_2048_R1.10_nominal_ZodiCorrected.fits}}<br />
|-<br />
| '''857GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_857_2048_R1.10_nominal_ZodiCorrected.fits|link=HFI_SkyMap_857_2048_R1.10_nominal_ZodiCorrected.fits}}<br />
|- bgcolor="ffdead"<br />
! Frequency || Combined frequency maps<br />
|-<br />
| '''All''' || {{PLASingleFile|fileType=file|name=COM_MapSet_I-allFreqs_R1.10_nominal.fits|link=COM_MapSet_I-allFreqs_R1.10_nominal.fits}} <br />
|}<br />
<br />
<br />
{| class="wikitable" align="center" style="text-align:center" border="1" cellpadding="5" cellspacing="0" width=850px<br />
|+ '''FITS filenames'''<br />
|- bgcolor="ffdead"<br />
! Frequency || Survey 1 maps || Survey 2 maps<br />
|-<br />
| '''30GHz''' || {{PLASingleFile|fileType=map|name=LFI_SkyMap_030_1024_R1.10_survey_1.fits|link=LFI_SkyMap_030_1024_R1.10_survey_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=LFI_SkyMap_030_1024_R1.10_survey_2.fits|link=LFI_SkyMap_030_1024_R1.10_survey_2.fits}}<br />
|-<br />
| '''44GHz''' || {{PLASingleFile|fileType=map|name=LFI_SkyMap_044_1024_R1.10_survey_1.fits|link=LFI_SkyMap_044_1024_R1.10_survey_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=LFI_SkyMap_044_1024_R1.10_survey_2.fits|link=LFI_SkyMap_044_1024_R1.10_survey_2.fits}}<br />
|-<br />
| '''70GHz''' || {{PLASingleFile|fileType=map|name=LFI_SkyMap_070_1024_R1.10_survey_1.fits|link=LFI_SkyMap_070_1024_R1.10_survey_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=LFI_SkyMap_070_1024_R1.10_survey_2.fits|link=LFI_SkyMap_070_1024_R1.10_survey_2.fits}}<br />
|-<br />
| '''70GHz''' || {{PLASingleFile|fileType=map|name=LFI_SkyMap_070_2048_R1.10_survey_1.fits|link=LFI_SkyMap_070_2048_R1.10_survey_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=LFI_SkyMap_070_2048_R1.10_survey_2.fits|link=LFI_SkyMap_070_2048_R1.10_survey_2.fits}}<br />
|-<br />
| '''100GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_100_2048_R1.10_survey_1.fits|link=HFI_SkyMap_100_2048_R1.10_survey_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_100_2048_R1.10_survey_2.fits|link=HFI_SkyMap_100_2048_R1.10_survey_2.fits}}<br />
|-<br />
| '''143GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_143_2048_R1.10_survey_1.fits|link=HFI_SkyMap_143_2048_R1.10_survey_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_143_2048_R1.10_survey_2.fits|link=HFI_SkyMap_143_2048_R1.10_survey_2.fits}}<br />
|-<br />
| '''217GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_217_2048_R1.10_survey_1.fits|link=HFI_SkyMap_217_2048_R1.10_survey_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_217_2048_R1.10_survey_2.fits|link=HFI_SkyMap_217_2048_R1.10_survey_2.fits}}<br />
|-<br />
| '''353GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_353_2048_R1.10_survey_1.fits|link=HFI_SkyMap_353_2048_R1.10_survey_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_353_2048_R1.10_survey_2.fits|link=HFI_SkyMap_353_2048_R1.10_survey_2.fits}}<br />
|-<br />
| '''545GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_545_2048_R1.10_survey_1.fits|link=HFI_SkyMap_545_2048_R1.10_survey_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_545_2048_R1.10_survey_2.fits|link=HFI_SkyMap_545_2048_R1.10_survey_2.fits}}<br />
|-<br />
| '''857GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_857_2048_R1.10_survey_1.fits|link=HFI_SkyMap_857_2048_R1.10_survey_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_857_2048_R1.10_survey_2.fits|link=HFI_SkyMap_857_2048_R1.10_survey_2.fits}}<br />
|- bgcolor="ffdead"<br />
! Frequency || Survey 1 Zodi-corrected maps || Survey 2 Zodi-corrected maps<br />
|-<br />
| '''100GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_100_2048_R1.10_survey_1_ZodiCorrected.fits|link=HFI_SkyMap_100_2048_R1.10_survey_1_ZodiCorrected.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_100_2048_R1.10_survey_2_ZodiCorrected.fits|link=HFI_SkyMap_100_2048_R1.10_survey_2_ZodiCorrected.fits}}<br />
|-<br />
| '''143GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_143_2048_R1.10_survey_1_ZodiCorrected.fits|link=HFI_SkyMap_143_2048_R1.10_survey_1_ZodiCorrected.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_143_2048_R1.10_survey_2_ZodiCorrected.fits|link=HFI_SkyMap_143_2048_R1.10_survey_2_ZodiCorrected.fits}}<br />
|-<br />
| '''217GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_217_2048_R1.10_survey_1_ZodiCorrected.fits|link=HFI_SkyMap_217_2048_R1.10_survey_1_ZodiCorrected.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_217_2048_R1.10_survey_2_ZodiCorrected.fits|link=HFI_SkyMap_217_2048_R1.10_survey_2_ZodiCorrected.fits}}<br />
|-<br />
| '''353GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_353_2048_R1.10_survey_1_ZodiCorrected.fits|link=HFI_SkyMap_353_2048_R1.10_survey_1_ZodiCorrected.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_353_2048_R1.10_survey_2_ZodiCorrected.fits|link=HFI_SkyMap_353_2048_R1.10_survey_2_ZodiCorrected.fits}}<br />
|-<br />
| '''545GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_545_2048_R1.10_survey_1_ZodiCorrected.fits|link=HFI_SkyMap_545_2048_R1.10_survey_1_ZodiCorrected.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_545_2048_R1.10_survey_2_ZodiCorrected.fits|link=HFI_SkyMap_545_2048_R1.10_survey_2_ZodiCorrected.fits}}<br />
|-<br />
| '''857GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_857_2048_R1.10_survey_1_ZodiCorrected.fits|link=HFI_SkyMap_857_2048_R1.10_survey_1_ZodiCorrected.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_857_2048_R1.10_survey_2_ZodiCorrected.fits|link=HFI_SkyMap_857_2048_R1.10_survey_2_ZodiCorrected.fits}}<br />
|- bgcolor="ffdead"<br />
! Frequency || Half-ring 1 maps ||Half-ring 2 maps<br />
|-<br />
| '''30GHz''' || {{PLASingleFile|fileType=map|name=LFI_SkyMap_030_1024_R1.10_nominal_ringhalf_1.fits|link=LFI_SkyMap_030_1024_R1.10_nominal_ringhalf_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=LFI_SkyMap_030_1024_R1.10_nominal_ringhalf_2.fits|link=LFI_SkyMap_030_1024_R1.10_nominal_ringhalf_2.fits}}<br />
|-<br />
| '''44GHz''' || {{PLASingleFile|fileType=map|name=LFI_SkyMap_044_1024_R1.10_nominal_ringhalf_1.fits|link=LFI_SkyMap_044_1024_R1.10_nominal_ringhalf_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=LFI_SkyMap_044_1024_R1.10_nominal_ringhalf_2.fits|link=LFI_SkyMap_044_1024_R1.10_nominal_ringhalf_2.fits}}<br />
|-<br />
| '''70GHz''' || {{PLASingleFile|fileType=map|name=LFI_SkyMap_070_1024_R1.10_nominal_ringhalf_1.fits|link=LFI_SkyMap_070_1024_R1.10_nominal_ringhalf_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=LFI_SkyMap_070_1024_R1.10_nominal_ringhalf_2.fits|link=LFI_SkyMap_070_1024_R1.10_nominal_ringhalf_2.fits}}<br />
|-<br />
| '''70GHz''' || {{PLASingleFile|fileType=map|name=LFI_SkyMap_070_2048_R1.10_nominal_ringhalf_1.fits|link=LFI_SkyMap_070_2048_R1.10_nominal_ringhalf_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=LFI_SkyMap_070_2048_R1.10_nominal_ringhalf_2.fits|link=LFI_SkyMap_070_2048_R1.10_nominal_ringhalf_2.fits}}<br />
|-<br />
| '''100GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_100_2048_R1.10_nominal_ringhalf_1.fits|link=HFI_SkyMap_100_2048_R1.10_nominal_ringhalf_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_100_2048_R1.10_nominal_ringhalf_2.fits|link=HFI_SkyMap_100_2048_R1.10_nominal_ringhalf_2.fits}}<br />
|-<br />
| '''143GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_143_2048_R1.10_nominal_ringhalf_1.fits|link=HFI_SkyMap_143_2048_R1.10_nominal_ringhalf_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_143_2048_R1.10_nominal_ringhalf_2.fits|link=HFI_SkyMap_143_2048_R1.10_nominal_ringhalf_2.fits}}<br />
|-<br />
| '''217GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_217_2048_R1.10_nominal_ringhalf_1.fits|link=HFI_SkyMap_217_2048_R1.10_nominal_ringhalf_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_217_2048_R1.10_nominal_ringhalf_2.fits|link=HFI_SkyMap_217_2048_R1.10_nominal_ringhalf_2.fits}}<br />
|-<br />
| '''353GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_353_2048_R1.10_nominal_ringhalf_1.fits|link=HFI_SkyMap_353_2048_R1.10_nominal_ringhalf_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_353_2048_R1.10_nominal_ringhalf_2.fits|link=HFI_SkyMap_353_2048_R1.10_nominal_ringhalf_2.fits}}<br />
|-<br />
| '''545GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_545_2048_R1.10_nominal_ringhalf_1.fits|link=HFI_SkyMap_545_2048_R1.10_nominal_ringhalf_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_545_2048_R1.10_nominal_ringhalf_2.fits|link=HFI_SkyMap_545_2048_R1.10_nominal_ringhalf_2.fits}}<br />
|-<br />
| '''857GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_857_2048_R1.10_nominal_ringhalf_1.fits|link=HFI_SkyMap_857_2048_R1.10_nominal_ringhalf_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_857_2048_R1.10_nominal_ringhalf_2.fits|link=HFI_SkyMap_857_2048_R1.10_nominal_ringhalf_2.fits}}<br />
|}<br />
<br />
''' FITS file structure '''<br />
<br />
<br />
[[File:FITS_FreqMap.png | 500px | right | thumb | '''FITS file structure''']]<br />
<br />
The FITS files for the sky maps contain a minimal primary header with no data, and a ''BINTABLE'' extension (EXTENSION 1, EXTNAME = ''FREQ-MAP'') containing the data. The structure is shows schematically in the figure at right. <br />
<br />
The ''FREQ-MAP'' extension contains is a 3-column table that contain the signal, hit-count and variance maps, all in Healpix format, in columns 1, 2, and 3, respectively. The number of rows is 50331648 for HFI and LFI 70 GHz at Nside=2048 and 12582912 for LFI maps at Nside=1024 (N.B: Npix = 12 Nside^2). The three columns are ''I_STOKES'' for the intensity (or temperature) signal, ''HIT'' for the hit-count and ''II_COV'' for the variance. The exact order of the columns in the figure is indicative only, and the details can be found in the keywords. <br />
<br />
Keywords indicate the coordinate system (GALACTIC), the Healpix ordering scheme (NESTED), the units (K_cmb or MJy/sr) of each column, and of course the frequency channel (FREQ). The COMMENT fields give a one-line summary of the product, and some other information useful for traceability within the DPCs. The original filename is also given in the ''FILENAME'' keyword as are the datasum and the md5 checksum for the extension. The ''BAD_DATA'' keyword gives the value used by Healpix to indicate pixels for which no signal is present (these will also have a hit-count value of 0). The COMMENT fields give further information including some traceability data for the DPC's. The main parameters are summarised below:<br />
<br />
<br />
{| border="1" cellpadding="3" cellspacing="0" align="center" style="text-align:left" width=800px<br />
|+ '''Sky map file data structure'''<br />
|- bgcolor="ffdead" <br />
!colspan="4" | 1. EXTNAME = 'FREQ-MAP' : Data columns<br />
|- bgcolor="ffdead" <br />
! Column Name || Data Type || Units || Description<br />
|-<br />
|I_STOKES || Real*4 || K_cmb or MJy/sr || The signal map<br />
|-<br />
|HITS || Int*4 || none || The hit-count map<br />
|-<br />
|II_COV || Real*4 || K_cmb<sup>2</sup> or (MJy/sr)<sup>2</sup> || The variance map<br />
|- bgcolor="ffdead" <br />
! Keyword || Data Type || Value || Description<br />
|-<br />
|PIXTYPE || string || HEALPIX ||<br />
|-<br />
|COORDSYS || string || GALACTIC ||Coordinate system <br />
|-<br />
|ORDERING || string || NESTED || Healpix ordering<br />
|-<br />
|NSIDE || Int || 1024 or 2048 || Healpix Nside <br />
|-<br />
|FIRSTPIX || Int*4 || 0 || First pixel number<br />
|-<br />
|LASTPIX || Int*4 || 12582911 or 50331647 || Last pixel number<br />
|-<br />
|FREQ || string || nnn || The frequency channel <br />
|}<br />
<br />
<br />
The same structure applies to all ''SkyMap'' products, independent of whether they are full channel, survey of half-ring. The distinction between the types of maps is present in the FITS filename (and in the traceability comment fields).<br />
<br />
''' References'''<br />
<br />
<References /><br />
<br />
<br />
</div><br />
</div><br />
<br />
<br />
<br />
[[Category:Mission products|002]]</div>Azaccheihttps://wiki.cosmos.esa.int/planck-legacy-archive/index.php?title=Frequency_maps&diff=14107Frequency maps2018-07-06T13:30:08Z<p>Azacchei: /* Types of map */</p>
<hr />
<div>{{DISPLAYTITLE:Frequency maps in Temperature and Polarization}}<br />
==General description==<br />
<br />
Sky maps give the best estimate of the intensity and polarization (Stokes <i>Q</i> and <i>U</i> components), if available, of the signal from the sky after removal, as far as possible, of known systematic effects (mostly instrumental, but including also the solar and Earth-motion dipoles, Galactic stray light, and the zodiacal light). The Planck Collaboration has made three releases of maps, in 2013, 2015 and 2018. This section describes the 2018 release. For descriptions of the other two releases, please go to 2013, and 2015.<br />
<br />
In the 2013, 2015 and 2018 releases, sky maps are provided for the full Planck mission using all valid detectors in each frequency channel, and also for various subsets obtained by splitting the mission into various time ranges or into subsets of the detectors in a given channel, or by considering only odd or even pointing periods. These products are especially interesting for characterization purposes (see also the [[HFI-Validation | data validation]] section), though some are also useful for the study of source variability. The details of the start and end of the time ranges are given in the table below. <br />
<br />
For this (2018) release, HFI is providing a more limited subset of maps that include the full channel maps, the half-mission and the odd-even ring splits. Also, note that for the 353 GHz band, both full channel and PSBs only maps are provided, and that by default it is the PBS-only maps that are served.<br />
<br />
<br />
{| border="1" cellpadding="3" cellspacing="0" align="center" style="text-align:left" width=800px<br />
|+ '''Ranges for mission and surveys'''<br />
|- bgcolor="ffdead" <br />
! Range || ODs || HFI rings || pointing-IDs || Comment<br />
|-<br />
|Nominal mission || 91 - 563 || 240 - 14723 || 00004200 - 03180200 ||<br />
|-<br />
|Full mission || 91 - 974 || 240 - 27005 || 00004200 - 05322620 || For HFI<br />
|-<br />
|Full mission || 91 - 1543 || n/a || 00004200 - 06511160 || For LFI<br />
|-<br />
|Survey 1 || 91 - 270 || 240 - 5720 || 00004200 - 01059820 ||<br />
|-<br />
|Survey 2 || 270 - 456 || 5721 - 11194 || 01059830 - 02114520 ||<br />
|-<br />
|Survey 3 || 456 - 636 || 11195 - 16691 || 02114530 - 03193660 ||<br />
|-<br />
|Survey 4 || 636 - 807 || 16692 - 21720 || 03193670 - 04243900 ||<br />
|-<br />
|Survey 5 || 807 - 974 || 21721 - 26050 || 05267180 - 05322590 || End of mission for HFI<br />
|-<br />
|Survey 5 || 807 - 993 || n/a || 05267180 - 06344800 || End of survey for LFI<br />
|-<br />
|Survey 6 || 993 - 1177 || n/a || 06344810 - 06398120 || LFI only <br />
|-<br />
|Survey 7 || 1177 - 1358 || n/a || 06398130 - 06456410 || LFI only <br />
|-<br />
|Survey 8 || 1358 - 1543 || n/a || 06456420 - 06511160 || LFI only <br />
|-<br />
|HFI mission-half-1 || 91 - 531 || 240 - 13471 || 00004200 - 03155580 ||<br />
|-<br />
|HFI mission-half-2 || 531 - 974 || 13472 - 27005 || 03155590 - 05322590 ||<br />
|-<br />
|LFI Year 1 || 91 - 456 || n/a || 00004200 - 02114520 ||<br />
|-<br />
|LFI Year 2 || 456 - 807 || n/a || 02114530 - 04243900 ||<br />
|-<br />
|LFI Year 3 || 807 - 1177 || n/a || 05267180 - 06398120 ||<br />
|-<br />
|LFI Year 4 || 1177 - 1543 || n/a || 06398130 - 06511160 ||<br />
|-<br />
|}<br />
<br />
To help in further processing, there are also masks of the Galactic plane and of point sources, each provided for several different depths. <br />
<br />
All sky maps are in HEALPix format, with <i>N</i><sub>side</sub>=1024 (for LFI 30, 44, and 70GHz) and 2048 (for LFI 70GHz and HFI), in Galactic coordinates, and with nested ordering. <br />
<br />
'''WARNING''': The HEALPix convention for polarization is <b>not</b> the same as the IAU convention ([[#Polarization convention used in the Planck project|Section 8 on this page]]).<br />
<br />
The signal is given in units of K<sub>CMB</sub> for 30 to 353 GHz, and of MJy.sr<sup>-1</sup> (for a constant &nu;<i>I</i><sub>&nu;</sub> energy distribution) for 545 and 857 GHz. For each frequency channel, the intensity and polarization maps are packaged into a "BINTABLE" extension of a FITS file together with a hit-counts map (or "hits map", for short, giving the number of observation samples that are accumulated in a pixel, all detectors combined) and with the variance and covariance maps. Additional information is given in the FITS file header. The structure of the FITS file is given in the [[#FITS_file_structure | FITS file structure]] section below.<br />
<br />
==Production process==<br />
<br />
Sky maps are produced by appropriately combining the data from all working detectors in a frequency channel over some period of the mission. They give the best estimate of the signal from the sky (unpolarized) after removal, as far as possible, of known systematic effects and of the dipole signals induced by the motion of the solar system in the CMB and of the Planck satellite in the solar system. In particular, they include the zodiacal light emission ("zodi" for short) and also the scattering from the far sidelobes of the beams (FSL). More on this below.<br />
<br />
=== HFI processing ===<br />
<br />
The mapmaking and calibration process is described in detail in the [[Map-making_LFI | mapmaking]] section and in the {{PlanckPapers|planck2016-XLVI}} paper, where detailed references can be found. In brief, the timelines are cleaned and calibrated and converted into HealPix rings (HPRs), then ''SRoll'' is applied to destripe them in polarised space (removal of very low frequency noise by minimising differences at ring crossing points), to remove knows systematic effects (including the flux calibration), and to project them onto a HealPix map.<br />
<br />
The processing yields maps of the signal, hit counts and auto- and cross-variance maps for the 6 full channel and for a pseudo-channel built from the 353 PSBs only. For each channel HFI provides <br />
* a map for the full mission<br />
* two maps for each half-mission<br />
* two maps for built from odd or even rings only<br />
<br />
for a total of 35 maps. <br />
<br />
==== PR3 HFI products ====<br />
<br />
===== Healpix Pixel Rings (HPRs) =====<br />
''SRoll'' main products are the HFI frequency maps. Nevertheless, we also make available the Healpix Pixel Rings (HPRs) of those maps, ie. the data before projection. See [[Healpix_Rings_HFI| description of those files]].<br />
<br />
===== Frequency maps =====<br />
<br />
The 35 HFI frequency maps of the PR3 Legacy Release are the followings:<br />
<br />
{| border="1" cellpadding="3" cellspacing="0" align="center" style="text-align:left" width=800px<br />
|+ '''PR3 HFI frequency maps'''<br />
|- bgcolor="ffdead"<br />
!<br />
!100 GHz<br />
!143 GHz<br />
!217 GHz<br />
!353 GHz<br />
!353_PSB GHz<br />
!545 GHz<br />
!857 GHz<br />
|-<br />
| Full mission<br />
| I, Q, U<br />
| I, Q, U<br />
| I, Q, U<br />
| I, Q, U<br />
| I, Q, U<br />
| I<br />
| I<br />
|-<br />
| Half mission 1<br />
| I, Q, U<br />
| I, Q, U<br />
| I, Q, U<br />
| I, Q, U<br />
| I, Q, U<br />
| I<br />
| I<br />
|-<br />
| Half mission 2<br />
| I, Q, U<br />
| I, Q, U<br />
| I, Q, U<br />
| I, Q, U<br />
| I, Q, U<br />
| I<br />
| I<br />
|-<br />
| Odd rings<br />
| I, Q, U<br />
| I, Q, U<br />
| I, Q, U<br />
| I, Q, U<br />
| I, Q, U<br />
| I<br />
| I<br />
|-<br />
| Even rings<br />
| I, Q, U<br />
| I, Q, U<br />
| I, Q, U<br />
| I, Q, U<br />
| I, Q, U<br />
| I<br />
| I<br />
|}<br />
<br />
See [[Frequency_maps|description of those files]]. These maps are available on the [[https://www.cosmos.esa.int/web/planck/pla| Planck Legacy Archive]].<br />
<br />
<br />
=== LFI processing ===<br />
LFI maps were constructed with the MADAM mapmaking code, version 3.7.4. The code is based on a generalized destriping technique, where the correlated noise component is modelled as a sequence of constant offsets, called "baselines". A noise filter was used to constrain the baseline solution, allowing the use of 0.25-s and 1-s baselines for the 30 and 44GHz, and 70 GHz channels, respectively. See section 6 of {{PlanckPapers|planck2016-l02}}.<br />
<br />
<br />
Radiometers were combined according to the horn-uniform weighting scheme to minimize systematics. The flagged samples were excluded from the analysis by setting their weights to <i>C</i><sub>w</sub><sup>-1</sup> = 0. The Galaxy region was masked out in the destriping phase, to reduce errors arising from strong signal gradients. The polarization component was included in the analysis. <br />
<br />
; Dipole and Far Side Lobe correction: Input timelines are cleaned by the 4&pi;-convolved dipole and Galactic stray light, obtained as a convolution of the 4&pi; in-band far sidelobes and Galactic simulations, as explained in {{PlanckPapers|planck2016-l02}}. <br />
<br />
Scaling of the maps due to beam effects is taken into account in the LFI's beam functions (as provided in [[The_RIMO|the RIMO]]) which should be used for analysis of diffuse components.<br />
<br />
; Bandpass leakage correction :LFI high-resolution maps have been reseleased corrected for bandpass leakage or uncorrected. Further details about the procedure used to generate the bandpass correction maps can be found in section 7 of {{PlanckPapers|planck2016-l02}}.<br />
<br />
; Map zero-level : The 30, 44 and 70 GHz, maps are corrected for a zero-level monopole by applying an offset correction (see the LFI Calibration paper, {{PlanckPapers|planck2014-a06}}). Note that the offset applied is indicated in the header as a comment keyword.<br />
<br />
A detailed description of the mapmaking procedure is given in {{PlanckPapers|planck2013-p02}}, {{PlanckPapers|planck2014-a03}}, {{PlanckPapers|planck2014-a07}} and in the [[Map-making LFI#Map-making|Mapmaking]] section here, in {{PlanckPapers|planck2016-l02}} only a summary is reported.<br />
<br />
==Types of map ==<br />
<br />
=== Full-mission, full-channel maps (7 HFI, 4 LFI)===<br />
<br />
Full channel maps are built using all the valid detectors of a frequency channel and cover either the full or the nominal mission. For HFI, the 143-8 and 545-3 bolometers are rejected entirely, since they are seriously affected by RTS noise. HFI provides the Q and U components for the 100, 143, 217 and 353 GHz channels only. LFI provides the <i>I</i>, <i>Q</i>, and <i>U</i> maps for all the channels. Note that the HFI <i>Q</i> and <i>U</i> maps are corrected for bandpass leakage, but the LFI <i>Q</i> and <i>U</i> maps are not. The <i>I</i>, <i>Q</i>, and <i>U</i> maps are displayed in the figures below. The colour range here is set using a histogram equalization scheme (from HEALPix) that is useful for these non-Gaussian data fields. For visualization purposes, the <i>Q</i> and <i>U</i> maps shown here have been smoothed with a 1&deg; Gaussian kernel, otherwise they look like noise to the naked eye. The 70 GHz full map is also available at <i>N</i><sub>side</sub>=2048.<br />
<br />
The high dynamic range colour scheme of the Planck maps is described [https://wiki.cosmos.esa.int/planck-legacy-archive/index.php/Planck_high_dynamic_range_colour_palette here].<br />
<br />
<center><br />
<gallery style="padding:0 0 0 0;" perrow=3 widths=260px heights=160px> <br />
File: LFI_030GHz_dx12_I.png| '''Full mission <i>I</i>, 30 GHz.'''<br />
File: LFI_044GHz_dx12_I.png| '''Full mission <i>I</i>, 44 GHz.'''<br />
File: LFI_070GHz_dx12_I.png| '''Full mission <i>I</i>, 70 GHz.'''<br />
File: SkyMap100e.png| '''Full mission <i>I</i>, 100 GHz.'''<br />
File: SkyMap143e.png| '''Full mission <i>I</i>, 143 GHz.'''<br />
File: SkyMap217e.png| '''Full mission <i>I</i>, 217 GHz.'''<br />
File: SkyMap353e.png| '''Full mission <i>I</i>, 353 GHz.'''<br />
File: SkyMap545e.png| '''Full mission <i>I</i>, 545 GHz.'''<br />
File: SkyMap857e.png| '''Full mission <i>I</i>, 857 GHz.'''<br />
</gallery><br />
</center><br />
<br><br />
<center><br />
<gallery style="padding:0 0 0 0;" perrow=3 widths=260px heights=160px> <br />
File: LFI_030GHz_dx12_Q.png| '''Full mission <i>Q</i>, 30 GHz.'''<br />
File: LFI_044GHz_dx12_Q.png | '''Full mission <i>Q</i>, 44 GHz.'''<br />
File: LFI_070GHz_dx12_Q.png | '''Full mission <i>Q</i>, 70 GHz.'''<br />
File: HFI_Skymap_100_full_bplcorrected_sm1deg_Qb.png | '''Full mission <i>Q</i>, 100 GHz.'''<br />
File: HFI_Skymap_143_full_bplcorrected_sm1deg_Qb.png | '''Full mission <i>Q</i>, 143 GHz.'''<br />
File: HFI_Skymap_217_full_bplcorrected_sm1deg_Qb.png | '''Full mission <i>Q</i>, 217 GHz.'''<br />
File: HFI_Skymap_353_full_bplcorrected_sm1deg_Qb.png | '''Full mission <i>Q</i>, 353 GHz.'''<br />
</gallery><br />
</center><br />
<br><br />
<center><br />
<gallery style="padding:0 0 0 0;" perrow=3 widths=260px heights=160px> <br />
File: LFI_030GHz_dx12_U.png| '''Full mission <i>U</i>, 30 GHz.'''<br />
File: LFI_044GHz_dx12_U.png | '''Full mission <i>U</i>, 44 GHz.'''<br />
File: LFI_070GHz_dx12_U.png | '''Full mission <i>U</i>, 70 GHz.'''<br />
File: HFI_Skymap_100_full_bplcorrected_sm1deg_Ub.png | '''Full mission <i>U</i>, 100 GHz.'''<br />
File: HFI_Skymap_143_full_bplcorrected_sm1deg_Ub.png | '''Full mission <i>U</i>, 143 GHz.'''<br />
File: HFI_Skymap_217_full_bplcorrected_sm1deg_Ub.png | '''Full mission <i>U</i>, 217 GHz.'''<br />
File: HFI_Skymap_353_full_bplcorrected_sm1deg_Ub.png | '''Full mission <i>U</i>, 353 GHz.'''<br />
</gallery><br />
<br />
</center><br />
<br />
=== Full mission light maps, full channel maps (7 HFI, 7 LFI)===<br />
<br />
These maps are based on the Full mission maps but contain fewer columns, IQU from 30 to 353 GHz, and I only at 545 and 857 GHz. These maps have been produced to reduce the transfer time of the most downloaded frequency full mission maps.<br />
<br />
=== Single-survey, full-channel maps (35 LFI)===<br />
<br />
Single-survey maps are built using all valid detectors of a frequency channel; they separately cover the different sky surveys. The surveys are defined as the times over which the satellite spin axis rotates by 180&deg;, which, due to the position of the detectors in the focal plane does not cover the full sky, but a fraction between about 80% and 90%, depending on detector position. During adjacent surveys the sky is scanned in opposite directions (more precisely it is the ecliptic equator that is scanned in opposite directions). While these are useful to investigate variable sources, they are also used to study the systematics of the time-response of the detectors as they scan bright sources, like the Galactic Plane, in different directions during different survey. Note that the HFI and LFI missions cover five and eight surveys, respectively, and in the case of HFI the last survey in incomplete.<br />
The 70 GHz survey maps are available also at <i>N</i><sub>side</sub>=2048. Note that LFI provides a special survey-map combination used in the low-&#8467; analysis; this maps, available at the three LFI frequencies, 30, 44, and 70 GHz, was built using the combination of Surveys 1, 3, 5, 6, 7, and 8.<br />
<br />
=== Year maps, full-channel maps (16 LFI)===<br />
<br />
These maps are built using the data of Surveys 1+2, Surveys 3+4, and so forth. They are used to study long-term systematic effects. The 70 GHz years maps are available also at <i>N</i><sub>side</sub>=2048.<br />
<br />
===Half-mission maps, full-channel maps (14 HFI, 12 LFI)===<br />
<br />
For HFI, the half mission is defined after eliminating those rings that are discarded for all bolometers, many of which occurred during the 5th survey when the "End-of-Life" tests were performed. The remaining rings are divided in half to define the two halves of the mission. This exercise is done for the full mission only.<br />
<br />
For LFI, instead of the half-mission maps, the following year combinations have been created: Year 1+2, Year 1+3, Year 2+4, Year 3+4,<br />
<br />
===Full mission, single-detector maps (22 LFI)===<br />
<br />
For LFI, all the 22 Radiometers maps are available, and (obviously) only in Stokes <i>I</i>.<br />
<br />
===Full-mission, detector-set or detector-pairs maps (8 LFI)===<br />
<br />
The objective here is to build independent temperature (<i>I</i>) and polarization (<i>Q</i> and <i>U</i>) maps using the two pairs of polarization-sensitive detectors of each channel where they are available, i.e., for the 44-353 GHz channels. The table below indicates which detectors were used to build each detector set (detset).<br />
<br />
{| border="1" cellpadding="3" cellspacing="0" align="center" style="text-align:left" width=600px<br />
|+ '''Definition of LFI detector pairs'''<br />
|- bgcolor="ffdead" <br />
!Frequency || Horn pair || Comment <br />
|-<br />
|44 GHz || 24 || This map is only in temperature<br />
|-<br />
|44 GHz || 25 and 26 || <br />
|-<br />
|70 GHz || 18 and 23 || Available also at <i>N</i><sub>side</sub>=2048<br />
|-<br />
|70 GHz || 19 and 22 || Available also at <i>N</i><sub>side</sub>=2048<br />
|-<br />
|70 GHz || 20 and 21 || Available also at <i>N</i><sub>side</sub>=2048<br />
|}<br />
<br />
===Half-ring maps (62 LFI)===<br />
<br />
These maps are similar to the ones described above, but are built using only the first or the second halves of each ring (or pointing period). The HFI provides half-ring maps for the full mission only, as well as for the full channel, the detsets, and the single bolometers. The LFI provides half-ring maps for the full mission in each channel (70 GHz also at <i>N</i><sub>side</sub>=2048), for the full-mission radiometers, and for the full-mission horn pairs.<br />
<br />
=== Odd and even rings maps (14 HFI)<br />
<br />
As the name indicates, these are generated by using only the odd or only the even rings.<br />
<br />
=== Caveats and known issues ===<br />
<br />
'''TBC'''<br />
<br />
==== Caveats when using the HFI frequency maps ====<br />
Some imperfections have shown up in the tests of the HFI PR3 maps that were previously hidden by higher-level systematics in the previous PR2 data. These lead to guidelines for the proper use of the HFI PR3 data.<br />
<br />
===== Monopoles =====<br />
Monopoles, which cannot be extracted from Planck data alone, are adjusted at each frequency (as was done in the previous PR2 release). For component separation, this provides maps that can be used directly in combination with other tracers.<br />
This monopole includes a CIB model, a diffuse ISM signal adjusted on the HI tracer, and a zodiacal emission signal adjusted to the proper absolute intensity.<br />
<br />
=====Use of the 353 GHz SWBs ===== <br />
We deliver two data sets: the recommended one not using the 353 GHz SWBs data, and the other one including the 353 GHz SWBs for specific use like, for example, increasing the signal to noise level at high multipoles.<br />
<br />
===== Color correction and component separation=====<br />
Different responses between bolometers to different foregrounds cannot be used with the PR3 release to extract component maps. Single bolometer maps computed by Sroll in a frequency band, are all adjusted by construction to the band average response.<br />
<br />
===== Sub-pixel effect in very bright regions===== <br />
The bandpass corrections have been optimized for high latitude regions which implied to reduce the noise of the CO and dust bandpass templates to avoid the introduction of significant correlated noise. The effect is negligible for dust but not for CO in very bright regions. See [[subpixel_HFI|detailled description]].<br />
<br />
===== Solar dipole residual===== <br />
The ''Planck'' 2015 Solar dipole is removed from the PR3 HFI maps to be consistent with LFI maps and to facilitate comparison with the previous PR2 ones. The best Solar dipole determination from HFI PR3 data shows a small shift in direction of about 1', but a 1.8 &mu;K lower amplitude. Removal of the ''Planck'' 2015 Solar dipole thus leaves a small but non-negligible dipole residual in the HFI PR3 maps. To correct for this, and adjust maps at the best photometric calibration, users of the HFI PR3 maps should:<br />
# put back into the maps the ''Planck'' 2015 Solar dipole (d,l,b)= (3364.5 &plusmn; 2.0 &mu;K, 264.00 &plusmn; 0.03&deg;, 48.24 &plusmn; 0.02&deg;),<br />
# include the [[#Calibration accuracy|absolute calibration frequency bias]], i.e., multiply by 1 minus the calibration bias,<br />
# lastly, remove the [[#HFI 2018 Solar dipole|HFI 2018 Solar dipole]].<br />
<br />
==Inputs==<br />
=== HFI inputs ===<br />
<br />
The HFI mapmaking takes as input:<br />
* the cleaned TOIs of the signal from each detector, together with their flags, produced by the [[TOI processing|TOI processing]] pipeline;<br />
* the TOIs of pointing (quaternions), described in [[Detector_pointing|Detector pointing]];<br />
* bolometer-level characterization data, from the DPC's internal IMO (not distributed);<br />
* Planck orbit data, used to compute and remove the Earth's dipole;<br />
* Planck solar dipole information, used to calibrate the CMB channels;<br />
* planet models used to calibrate the Galactic channels.<br />
<br />
=== LFI inputs ===<br />
<br />
The MADAM mapmaker takes as input:<br />
* the calibrated timelines (for details see [[TOI processing LFI|TOI Processing]]);<br />
* the detector pointings (for details see [[Detector_pointing|Detector pointing]]);<br />
* the noise information in the form of 3-parameter (white noise level &sigma;, slope, and knee frequency <i>f</i><sub>knee</sub>) noise model (for details see [[The RIMO|RIMO]]).<br />
<br />
==Related products==<br />
=== Masks ===<br />
This section presents the "general purpose" masks. Other masks specific to certain products are packaged with those products.<br />
<br />
Note that for this release, HFI has not produced any new masks. <br />
<br />
==== Gatactic Centre masks ====<br />
<br />
'''TBW'''<br />
<br />
<br />
====Point source masks [TO BE REMOVED ??]====<br />
<br />
For HFI and LFI two sets of point-source masks are provided. <br />
* Intensity masks, which remove sources detected with S/N > 5. <br />
* Polarisation masks, which remove sources that have polarization detection significance levels of 99.97 % or greater at the position of a source detected in intensity. They were derived from the polarization maps with dust foreground bandpass mismatch leakage corrections applied. The area excised around each source has a radius of 3σ (width) of the beam, i.e., 1.27 FWHM (for LFI the cut around each source has a radius of 32 arcmin at 30GHz, 27 arcmin at 44 GHz, and 13 arcmin at 70 GHz).<br />
<br />
Both sets of masks are found in the files ''HFI_Mask_PointSrc_2048_R2.00.fits'' and ''LFI_Mask_PointSrc_2048_R2.00.fits'', in which the first extension contains the intensity masks, and the second contains the polarization masks.<br />
<br />
====Galactic plane masks [TO BE REMOVED ??]====<br />
<br />
Eight Galactic emission masks are provided, giving 20, 40, 60, 70, 80, 90, 97, and 99% sky coverage, derived from the 353 GHz map after CMB subtraction. These are independent of frequency channel. Three versions are given: not apodized; and apodized by 2&deg; and 5&deg;. The filenames are ''HFI_Mask_GalPlane-apoN_2048_R2.00.fits'', where <i>N</i> = 0, 2, and 5.<br />
<br />
The masks are shown below. The eight "GalPlane" masks are combined (added together) and shown in a single figure for each of the three apodizations. While the result is quite clear for the case of no apodization, it is less so for the apodized case. The "PointSrc" masks are shown separately for the intensity case.<br />
<br />
<center><br />
<gallery perrow=3 widths=260px heights=160px ><br />
File: GalPlaneMask_apo0.png | '''Galactic plane masks, no apodization.'''<br />
File: GalPlaneMask_apo2.png | '''Galactic plane masks, apodized to 2&deg;.'''<br />
File: GalPlaneMask_apo5.png | '''Galactic plane masks, apodized to 5&deg;.'''<br />
File: PointSrcMask_100.png | '''Point source mask, 100 GHz.'''<br />
File: PointSrcMask_143.png | '''Point source mask, 143 GHz.'''<br />
File: PointSrcMask_217.png | '''Point source mask, 217 GHz.'''<br />
File: PointSrcMask_353.png | '''Point source mask, 343 GHz.'''<br />
File: PointSrcMask_545.png | '''Point source mask, 545 GHz.'''<br />
File: PointSrcMask_857.png | '''Point source mask, 857 GHz.'''<br />
</gallery><br />
</center><br />
<br />
== File names ==<br />
The FITS filenames are of the form ''{H|L}FI_SkyMap_fff{-tag}_Nside_R2.nn_{coverage}-{type}.fits'', where "fff" are three digits to indicate the Planck frequency band, "tag" indicates the single detector or the detset (no "tag" indicates full channel), "Nside" is the HEALPix <i>N</i><sub>side</sub> value of the map, "coverage" indicates which part of the mission is covered (full, half mission, survey, year, etc.), and the optional "type" indicates the subset of input data used. The table below lists the products by type, with the appropriate unix wildcards that form the full filename.<br />
<br />
{| class="wikitable" align="center" style="text-align"left" border="1" cellpadding="15" cellspacing="20" width=880px<br />
|+ '''HFI FITS filenames'''<br />
|- bgcolor="ffdead"<br />
! Coverage || Filename <br />
|-<br />
| Full channel, full mission ||HFI_SkyMap_fff{-tag}_2048_R3.??_full.fits<br />
|-<br />
| Full channel, half mission || HFI_SkyMap_fff{-tag}_2048_R3.??_halfmission-{1/2}.fits<br />
|-<br />
| Full channel, full mission, odd/even ring || HFI_SkyMap_fff{-tag}_2048_R3.??_{odd/even}ring.fits <br />
|}<br />
<br />
{| class="wikitable" align="center" style="text-align"left" border="1" cellpadding="15" cellspacing="20" width=1000px<br />
|+ '''LFI FITS filenames'''<br />
|- bgcolor="ffdead"<br />
! Coverage || Filename || Half-ring filename || Comment<br />
|-<br />
| Full channel, full mission ||LFI_SkyMap_???_1024_R2.??_full.fits ||LFI_SkyMap_???_1024_R2.??_full-ringhalf-?.fits || Available also at Nside = 2048<br />
|-<br />
| Full channel, single survey || LFI_SkyMap_???_1024_R2.??_survey-?.fits || n/a || Available also at <i>N</i><sub>side</sub>=2048<br />
|-<br />
| Full channel, survey combination || LFI_SkyMap_???_1024_R2.??_survey-1-3-5-6-7-8.fits || n/a || n/a<br />
|-<br />
| Full channel, single year || LFI_SkyMap_???_1024_R2.??_year-?.fits || n/a || Available also at <i>N</i><sub>side</sub>=2048<br />
|-<br />
| Full channel, year combination || LFI_SkyMap_???_1024_R2.??_year?-?.fits || n/a || n/a<br />
|-<br />
| Horn pair, full mission || LFI_SkyMap_???-??-??_1024_R2.??_full.fits || LFI_SkyMap_???_??-??_1024_R2.??_full-ringhalf-?.fits || Available also at <i>N</i><sub>side</sub>2048<br />
|-<br />
| Single radiometer, full mission || LFI_SkyMap_???-???_1024_R2.??_full.fits || LFI_SkyMap_???-???_1024_R2.??_full-ringhalf-?.fits || n/a<br />
|}<br />
<br />
For the benefit of users who are only looking for the frequency maps with no additional information, we also provide a file combining the nine frequency maps as separate columns in a single extension. The nine columns in this file contain the intensity maps <i>only</i> and no other information (hits maps or variance maps) is provided.<br />
<br />
== FITS file structure ==<br />
<br />
The FITS files for the sky maps contain a minimal primary header with no data, and a ''BINTABLE'' extension (EXTENSION 1, EXTNAME = ''FREQ-MAP'') containing the data. The structure is shown schematically in the figure below. The ''FREQ-MAP'' extension contains a 3- or 10-column table that contain the signal, hit-count, and variance maps, all in HEALPix format. The 3-column case is for intensity only maps, while the 10-column case is for polarization. The number of rows is the number of map pixels, which is <i>N</i><sub>pix</sub> = 12 <i>N</i><sub>side</sub><sup>2</sup> for HEALPix maps, where <i>N</i><sub>side</sub> = 1024 or 2048 for most the maps presented in this section.<br />
<br />
[[File:FITS_FreqMap.png | 550px | center | thumb | '''FITS file structure.''']]<br />
<br />
Note that file sizes are approximately 0.6 GB for <i>I</i>-only maps and 1.9 GB for <i>IQU</i> maps at <i>N</i><sub>side</sub>=2048, but about 0.14 GB for <i>I</i>-only maps and 0.45 GB for <i>IQU</i> maps at <i>N</i><sub>pix</sub>=1024 .<br />
<br />
Keywords indicate the coordinate system ("GALACTIC"), the HEALPix ordering scheme ("NESTED"), the units (K<sub>CMB</sub> or MJy.sr<sup>-1</sup>) of each column, and of course the frequency channel ("FREQ"). Where polarization <i>Q</i> and <i>U</i> maps are provided, the "COSMO" polarization convention (used in HEALPix) is adopted, and it is specified in the "POLCCONV" keyword (see [[Sky_temperature_maps#Polarization_convention_used_in_the_Planck_project|this section]]). The "COMMENT" fields give a one-line summary of the product, and some other information useful for traceability within the DPCs. The original filename is also given in the "FILENAME" keyword. The "BAD_DATA" keyword gives the value used by HEALPix to indicate pixels for which no signal is present (these will also have a hit-count value of 0). The main parameters are summarized in the table below.<br />
<br />
{| border="1" cellpadding="3" cellspacing="0" align="center" style="text-align:left" width=800px<br />
|+ '''Sky map file data structure'''<br />
|- bgcolor="ffdead" <br />
!colspan="4" | 1. EXTNAME = 'FREQ-MAP' : Data columns<br />
|- bgcolor="ffdead" <br />
! Column name || Data type || Units || Description<br />
|-<br />
|I_STOKES || Real*4 || K<sub>CMB</sub> or MJy.sr<sup>-1</sup> || Stokes <i>I</i> map<br />
|-<br />
|Q_STOKES || Real*4 || K<sub>CMB</sub> or MJy.sr<sup>-1</sup> || Stokes <i>Q</i> map (optional)<br />
|-<br />
|U_STOKES || Real*4 || K<sub>CMB</sub> or MJy.sr<sup>-1</sup> || Stokes <i>U</i> map (optional)<br />
|-<br />
|HITS || Int*4 || none || The hit-count map<br />
|-<br />
|II_COV || Real*4 || K<sub>CMB</sub><sup>2</sup> or (MJy.sr<sup>-1</sup>)<sup>2</sup> || <i>II</i> variance map<br />
|-<br />
|IQ_COV || Real*4 || K<sub>CMB</sub><sup>2</sup> or (MJy.sr<sup>-1</sup>)<sup>2</sup> || <i>IQ</i> variance map (optional)<br />
|-<br />
|IU_COV || Real*4 || K<sub>CMB</sub><sup>2</sup> or (MJy.sr<sup>-1</sup>)<sup>2</sup> || <i>IQ</i> variance map (optional)<br />
|-<br />
|QQ_COV || Real*4 || K<sub>CMB</sub><sup>2</sup> or (MJy.sr<sup>-1</sup>)<sup>2</sup> || <i>QQ</i> variance map (optional)<br />
|-<br />
|QU_COV || Real*4 || K<sub>CMB</sub><sup>2</sup> or (MJy.sr<sup>-1</sup>)<sup>2</sup> || <i>QU</i> variance map (optional)<br />
|-<br />
|UU_COV || Real*4 || K<sub>CMB</sub><sup>2</sup> or (MJy.sr<sup>-1</sup>)<sup>2</sup> || <i>UU</i> variance map (optional)<br />
|-<br />
|- bgcolor="ffdead" <br />
! Keyword || Data type || Value || Description<br />
|-<br />
|PIXTYPE || String || HEALPIX ||<br />
|-<br />
|COORDSYS || String || GALACTIC ||Coordinate system <br />
|-<br />
|ORDERING || String || NESTED || Healpix ordering<br />
|-<br />
|POLCCONV || String || COSMO || Polarization convention<br />
|-<br />
|NSIDE || Int || 1024 or 2048 || HEALPix <i>N</i><sub>side</sub> <br />
|-<br />
|FIRSTPIX || Int*4 || 0 || First pixel number<br />
|-<br />
|LASTPIX || Int*4 || 12 <i>N</i><sub>side</sub><sup>2</sup> – 1 || Last pixel number<br />
|-<br />
|FREQ || String || nnn || Frequency channel <br />
|}<br />
<br />
<br />
The same structure applies to all "SkyMap" products, independent of whether they are full channel, survey of half-ring. The distinction between the types of maps is present in the FITS filename (and in the traceability comment fields).<br />
<br />
==Polarization convention used in the Planck project==<br />
<br />
The FITS keyword "POLCCONV" defines the polarization convention of the data within the file.<br />
The Planck collaboration used the COSMO convention for the polarization angle (as usually adopted in space-based and other CMB missions), whereas other subfields of astronomy usually adopt the IAU convention. The basic difference comes down to whether one thinks of the light rays being emitted from the origin (the usual mathematics/physics convention) or converging on the observer from the sky (the usual astronomy convention), and hence the "obvious" choice is different for a physicists and for an astronomer. Given that CMB results are of interest to a wide range of both physicists and astronomers, there is no single choice of convention that everyone would regard as self-evident. Hence one simply has to be aware of the convention being adopted. Because of this the Planck Collaboration has taken pains to point out which convention is being used in publications and in data releases. In the following we describe the difference between these two conventions, and the consequence if it is <i>not</i> taken into account correctly in the analysis.<br />
<br />
[[File:conventions.png|thumb|center|400px|'''Figure 1. Polarization conventions, showing the COSMO convention (left) and IAU convention (right). The vector <math>\hat{z}</math> points in the outward direction in COSMO, and inwards in IAU. The bottom panel refers to the plane tangent to the sphere.''']]<br />
<br />
Changing the orientation convention is equivalent to a transformation &psi;'=&pi;-&psi; of the polarization angle (Figure 1). The consequence of this transformation is the inversion of the Stokes parameter <i>U</i>.<br />
The components of the polarization tensor in the helicity basis <math>\epsilon^{\pm}=(\hat{x}\pm i\hat{y})/\sqrt{2}</math> are<br />
<br />
<math><br />
(Q+iU)(\hat{n}) = \sum _{\ell m}a_{2,lm}{}_{2}Y_{\ell }^{m}(\hat{n}),<br />
\\(Q-iU)(\hat{n}) = \sum _{\ell m}a_{-2,lm}{}_{2}Y_{\ell }^{m}(\hat{n}),<br />
</math><br />
<br />
where <math>{}_{2}Y_{\ell }^{m}(\hat{n})</math> are the spin-weighted spherical harmonic functions.<br />
The <i>E</i> and <i>B</i> modes can be defined as<br />
<br />
<math><br />
E(\hat{n}) = \sum_{\ell m}a_{E,\ell m}Y_{\ell }^{m}(\hat{n}),<br />
\\B(\hat{n}) = \sum_{\ell m}a_{B,\ell m}Y_{\ell }^{m}(\hat{n}),<br />
</math><br />
<br />
where the coefficients <i>a<sub>E,&#8467;m</sub></i> and <i>a<sub>B,&#8467;m</sub></i> are derived from linear combinations of the <i>a<sub>2,&#8467;m</sub></i>, <i>a<sub>-2,&#8467;m</sub></i>, defined implicitly in the first equation (<i>Q</i>&plusmn; i<i>U</i>).<br />
<br />
[[File:test_gradient.jpg|thumb|center|400px|]]<br />
[[File:test_curl.jpg|thumb|center|400px|'''Figure 2. Error on Planck-LFI 70 GHz <i>EE</i> (top) and <i>BB</i> (bottom) power spectra, in the case of an incorrect choice being made for the polarization coordinate system convention (IAU instead of COSMO).''']]<br />
<br />
The effect of the sign inversion of <i>U</i> on the polarization spectra is a non-trivial mixing of <i>E</i> and <i>B</i> modes. <br />
An example of the typical error on <i>EE</i> and <i>BB</i> auto-spectra in the case of the wrong choice for the polarization basis is shown in Figure 2.<br />
<br />
<i>One should be careful</i> to be aware of the polarization convention that is being adopted. If the IAU convention is used in computing the power spectra, then the sign of the <i>U</i> component of the Planck maps must be inverted before computing the <i>E</i> and <i>B</i> modes.<br />
<br />
In astronomical applications it is common to define a pseudo-vector <i>P</i> to show the amplitude and orientation of<br />
polarization on a map. When plotting these line segments to show the orientation of the plane of polarization (or the orthogonal direction, often considered to be the projection of the magnetic field), the results are the same for both the COSMO and IAU conventions. This because the appearance of <i>P</i> is a property of the radiation and hence not affected by the sign of <i>U</i>.<br />
<br />
=== Note on the convention used in the Planck Catalogue of Compact Sources (PCCS) ===<br />
Planck non-cosmology papers sometimes follow the IAU convention for internal analysis, for ease of comparison with other studies (e.g., comparison of Planck-derived thermal dust emission polarization with the optical polarization of starlight). Nevertheless, Planck data products, such as component-separated maps, still use the COSMO convention. The one exception is for the compact source catalogue. Because catalogues of astronomical objects found by Planck need to be compared directly with other source catalogues, the polarized sources described in the Planck Catalogue of Compact Sources follow the IAU convention, and the polarization angles are defined on an interval of [-90&deg;,90&deg;]. To switch to the COSMO convention, the polarization angles listed in the catalogue should be shifted by 90&deg; and multiplied by -1.<br />
<br />
== References ==<br />
<References /><br />
<br />
<br />
<span style="background:green"><br />
<br />
<span style="background:green"><br />
== Previous releases ==<br />
<br />
<div class="toccolours mw-collapsible mw-collapsed" style="background-color: #FFDAB9;width:80%" ><br />
'''2015 Sky temperature and polarization maps'''<br />
<br />
<div class="mw-collapsible-content"><br />
<br />
<br />
'''General description'''<br />
<br />
Sky maps give the best estimate of the intensity and polarization (Stokes Q and U components), if available, of the signal from the sky after removal, as far as possible, of known systematic effects (mostly instrumental, but including also the solar and earth-motion dipole, Galactic strylight and the Zodiacal light). Sky maps are provided for the full Planck mission using all valid detectors in each frequency channel, and also for various subsets by splitting the mission in various time ranges or in subsets of the detectors in a given channel. These products are useful for the study of source variability, but they are especially interesting for characterisation purposes (see also the [[HFI-Validation | data validation]] section). The details of the start and end of the time ranges are given in the table below.<br />
<br />
To help in further processing, there are also masks of the Galactic Plane and of point sources, each provided for several different depths.<br />
<br />
All sky maps are in Healpix format, with Nside of 1024 (LFI 30, 44 and 70) and 2048 (LFI 70 and HFI), in Galactic coordinates, and Nested ordering. <br />
<br />
;WARNING: the Healpix convention for polarization is NOT the same as the IAU convention - see Section 8 in this page.<br />
<br />
The signal is given in units of K<sub>cmb</sub> for 30-353 GHz, and of MJy/sr (for a constant <math>\nu F_\nu</math> energy distribution ) for 545 and 857 GHz. For each frequency channel, the intensity and polarization maps are packaged into a ''BINTABLE'' extension of a FITS file together with a hit-count map (or hit map, for short, giving the number of observation samples that are cumulated in a pixel, all detectors combined) and with the variance and covariance maps. Additional information is given in the FITS file header. The structure of the FITS file is given in the [[#FITS_file_structure | FITS file structure]] section below. <br />
<br />
; R2.00 : this first release (Jan 2015) contains polarisation data for the 353 GHz channel only.<br />
; R2.01 : this second release (May 2015) adds polarisation data to the 100-217 GHz channels.<br />
; R2.02 : a full re-release to correct the Healpix bad pixel value in the maps which was altered during the preparation of the maps and not reset to the correct value (the valid pixels are unchanged). It also fixes some FITS keywords, and includes a full re-release of the Zodi correction maps, with the 100-217 GHz one now including the polarisation correction)<br />
<br />
{| border="1" cellpadding="3" cellspacing="0" align="center" style="text-align:left" width=800px<br />
|+ '''Ranges for mission and surveys'''<br />
|- bgcolor="ffdead" <br />
! Range || ODs || HFI rings || pointing-IDs || Comment<br />
|-<br />
|nominal mission || 91 - 563 || 240 - 14723 || 00004200 - 03180200 ||<br />
|-<br />
|full mission || 91 - 974 || 240 - 27005 || 00004200 - 05322620 || for HFI<br />
|-<br />
|full mission || 91 - 1543 || n/a || 00004200 - 06511160 || for LFI<br />
|-<br />
|Survey 1 || 91 - 270 || 240 - 5720 || 00004200 - 01059820 ||<br />
|-<br />
|Survey 2 || 270 - 456 || 5721 - 11194 || 01059830 - 02114520 ||<br />
|-<br />
|Survey 3 || 456 - 636 || 11195 - 16691 || 02114530 - 03193660 ||<br />
|-<br />
|Survey 4 || 636 - 807 || 16692 - 21720 || 03193670 - 04243900 ||<br />
|-<br />
|Survey 5 || 807 - 974 || 21721 - 27005 || 05267180 - 05322590 || end of mission for HFI<br />
|-<br />
|Survey 5 || 807 - 993 || n/a || 05267180 - 06344800 || end of survey for LFI<br />
|-<br />
|Survey 6 || 993 - 1177 || n/a || 06344810 - 06398120 || LFI only <br />
|-<br />
|Survey 7 || 1177 - 1358 || n/a || 06398130 - 06456410 || LFI only <br />
|-<br />
|Survey 8 || 1358 - 1543 || n/a || 06456420 - 06511160 || LFI only <br />
|-<br />
|Survey 9 || 1543 - 1604 || n/a || 06511170 - 06533320 || LFI only Not in this delivery<br />
|-<br />
|HFI mission-half-1 || 91 - 531 || 240 - 13471 || 00004200 - 03155580 ||<br />
|-<br />
|HFI mission-half-2 || 531 - 974 || 13472 - 27005 || 03155590 - 05322590 ||<br />
|-<br />
|LFI Year 1 || 91 - 456 || n/a || 00004200 - 02114520 ||<br />
|-<br />
|LFI Year 2 || 456 - 807 || n/a || 02114530 - 04243900 ||<br />
|-<br />
|LFI Year 3 || 807 - 1177 || n/a || 05267180 - 06398120 ||<br />
|-<br />
|LFI Year 4 || 1177 - 1543 || n/a || 06398130 - 06511160 ||<br />
|-<br />
|}<br />
<br />
'''Production process'''<br />
<br />
Sky maps are produced by combining appropriately the data of all working detectors in a frequency channel over some period of the mission. They give the best estimate of the signal from the sky (unpolarised) after removal, as far as possible, of known systematic effects and of the dipole signals induced by the motion of the solar system in the CMB and of the Planck satellite in the solar system. In particular, they include the Zodiacal light emission (Zodi for short) and also the scattering from the far-side lobes of the beams (FSL). More on this below.<br />
<br />
''' HFI processing '''<br />
<br />
The mapmaking and calibration process is described in detail in the [[Map-making_LFI | Map-making]] section and in the {{PlanckPapers|planck2014-a09}} paper, where detailed references are found. In brief it consists of:<br />
<br />
; binning the TOI data onto ''rings'' : Healpix rings (HPRs) are used here, each ring containing the combined data of one pointing period. <br />
; flux calibration : at 100-353 GHz, the flux calibration factors are determined by correlating the signal with the orbital dipole, which is determined very accurately from the Planck satellite orbital parameters provided by Flight Dynamics. This provides a single gain factor per bolometer. At 545 and 857 GHz the gain is determined from the observation of Uranus and Neptune (but not Jupiter which is too bright) and comparison to recent models made explicitly for this mission. A single gain is applied to all rings at these frequencies.<br />
; destriping : in order to remove low-frequency noise, an offset per ring is determined by minimizing the differences between HPRs at their crossings, and removed.<br />
; Zodiacal light correction : a Zodiacal light model is used to build HPRs of the the Zodi emission, which is subtracted from the calibrated HPRs.<br />
; projection onto the map : the offset-corrected, flux-calibrated, and Zodi-cleaned HPRs are projected onto Healpix maps, with the data of each bolometer weighted by a factor of 1/NET of that bolometer.<br />
<br />
These steps are followed by some post-processing which is designed to prepare the maps for the component separation work. This post processing consists of: <br />
<br />
; Dust bandpass leakage correction : the Q and U maps are corrected for the intensity-to-polarisation leakage caused by the foregrounds having a non-CMB spectrum, and as a consequence of the non-identical bandpasses on the different detectors (bandpass mismatch, or BPM). This correction is determined using the ''ground'' method as described in Section 7.3 of {{PlanckPapers|planck2014-a09}}. These correction maps can be found in the Planck Legacy Archive as ''HFI_CorrMap_???-dustleak-ground_2048_R2.0?_{coverage}.fits''. The correction is applied by subtracting the correction map from the corresponding input map. This correction is not applied to the nominal mission maps in order to maintain compatibility with the PR1 products. ''In fact this correction was computed and applied only to the products used in component separation'', so they were not applied to the single survey maps and to the half-ring maps, which are considered characterisation products.<br />
; Far Side Lobe calibration correction : the 100-217 maps are multiplied by factors of 1.00087, 1.00046, and 1.00043, respectively, to compensate for the non-removal of the far-side lobes, and similarly the corresponding covariance maps have also been corrected by multiplication by the square of the factor.<br />
; Fill missing pixels : missing pixels are filled in with a value that is the mean of valid pixels within a given radius. A radius of 1 deg is used for the full channel maps, and 1.5 deg is used for the detset maps. This step is not applied to the single survey maps since they have large swaths of the sky that are not covered.<br />
<br />
; Map zero-level : for the 100 to 857 GHz maps, the zero levels are set to their optimal levels for Galactic and CIB studies. A procedure for adjusting them to astrophysical values is given in the HFI Mapmaking and Calibration paper {{PlanckPapers|planck2014-a09}}.<br />
<br />
These maps provide the main mission products. Together with signal maps, hit count, variance, and variance maps are also produced. The hit maps give the (integer) number of valid TOI-level samples that contribute to the signal of each pixel. All valid samples are counted in the same way, i.e., there is no weighting factor applied. The variance maps project the white noise estimate, provided by the NETs, in the sky domain.<br />
<br />
Note that the nominal mission maps have not had the post-processing applied, which makes them more easily comparable to the PR1 products.<br />
<br />
''' LFI processing '''<br />
LFI maps were constructed with the Madam map-making code, version 3.7.4. The code is based on generalized destriping technique, where the correlated noise component is modeled as a sequence of constant offset, called baselines. A noise filter was used to constrain the baseline solution allowing the use of 0.25 s and 1 second baselines for the 30 and 44, 70 GHz respectively.<br />
<br />
Radiometers were combined according to the horn-uniform weighting scheme to minimize systematics. The used weights are listed in [[Map-making LFI#Map-making|Map-making]]. The flagged samples were excluded from the analysis by setting their weights to <math>C_{w}^{-1}</math> = 0. The galaxy region was masked out in the destriping phase, to reduce error arising from strong signal gradients. The polarization component was included in the analysis... <br />
<br />
; Dipole and Far Side Lobe correction : input timelines are cleaned by 4pi convolved dipole and Galactic Straylight obtained as convolution of the 4pi in band far sidelobes and Galactic Simulation as explained in Section 7.4 of {{PlanckPapers|planck2014-a03}}. <br />
<br />
Beam effects on the LFI maps are described in Section 7.1 of {{PlanckPapers|planck2014-a03}}. Scaling of the maps due to beam effects is taken into account in the LFI's beam functions (as provided in the RIMO, give reference) which should be used for analysis of diffuse components. To compute the flux densities of compact sources, correction must be made for beam effects (see Table 8 of {{PlanckPapers|planck2014-a03}})."<br />
<br />
; Bandpass leakage correction : '''as opposed to the HFI, the LFI high resolution maps have not been corrected for bandpass leakage. Only low resolution (nside 256) maps are provided with the bandpass correction'''. The correction maps (LFI_CorrMap_0??-BPassCorr_*.fits) can be found in the Planck Legacy Archive. Further details about the procedure used to generate the bandpass correction maps can be found in Section 11 of {{PlanckPapers|planck2014-a03}}.<br />
<br />
; Map zero-level : for the 30, 44 and 70 GHz, maps are corrected for zero level monopole by applying an offset correction, see LFI Calibration paper {{PlanckPapers|planck2014-a06}}. Note that the offset applied is indicated in the header as a comment keyword.<br />
<br />
A detailed description of the map-making procedure is given in {{PlanckPapers|planck2013-p02}}, {{PlanckPapers|planck2014-a03}}, {{PlanckPapers|planck2014-a07}} and in section [[Map-making LFI#Map-making|Map-making]].<br />
<br />
'''Types of maps '''<br />
<br />
''' Full mission, full channel maps (6 HFI, 4 LFI)'''<br />
<br />
Full channel maps are built using all the valid detectors of a frequency channel and cover the either the full or the nominal mission. For HFI, the 143-8 and 545-3 bolometers are rejected entirely as they are seriously affected by RTS noise. HFI provides the Q and U components for the 100, 143, 217 and 353 GHz channels only. LFI provides the I, Q and U maps for all the channels. Reminder: HFI Q and U maps are corrected for bandpass leakage but LFI Q and U maps are not. The I, Q and U maps are displayed in the figures below. The color range is set using a histogram equalisation scheme (from HEALPIX) that is useful for these non-Gaussian data fields. For visualization purposes, the Q and U maps shown here have been smoothed with a 1 degree Gaussian kernel, otherwise they look like noise to the naked eye.<br />
The 70 GHz full map is available also at <math>N_{side}</math> 2048.<br />
<br />
<center><br />
<gallery style="padding:0 0 0 0;" perrow=3 widths=260px heights=160px> <br />
File: SkyMap30e.png| '''Full mission I, 30 GHz'''<br />
File: SkyMap44e.png | '''Full mission I, 44 GHz'''<br />
File: SkyMap70e.png | '''Full mission I, 70 GHz'''<br />
File: SkyMap100e.png | '''Full mission I, 100 GHz'''<br />
File: SkyMap143e.png | '''Full mission I, 143 GHz'''<br />
File: SkyMap217e.png | '''Full mission I, 217 GHz'''<br />
File: SkyMap353e.png | '''Full mission I, 353 GHz'''<br />
File: SkyMap545e.png | '''Full mission I, 545 GHz'''<br />
File: SkyMap857e.png | '''Full mission I, 857 GHz'''<br />
</gallery><br />
</center><br />
<br><br />
<center><br />
<gallery style="padding:0 0 0 0;" perrow=3 widths=260px heights=160px> <br />
File: LFI_SkyMap_030_1024_R2.01_full_Qb_sm1deg.png| '''Full mission Q, 30 GHz'''<br />
File: LFI_SkyMap_044_1024_R2.01_full_Qb_sm1deg.png | '''Full mission Q, 44 GHz'''<br />
File: LFI_SkyMap_070_1024_R2.01_full_Qb_sm1deg.png | '''Full mission Q, 70 GHz'''<br />
File: HFI_Skymap_100_full_bplcorrected_sm1deg_Qb.png | '''Full mission Q, 100 GHz'''<br />
File: HFI_Skymap_143_full_bplcorrected_sm1deg_Qb.png | '''Full mission Q, 143 GHz'''<br />
File: HFI_Skymap_217_full_bplcorrected_sm1deg_Qb.png | '''Full mission Q, 217 GHz'''<br />
File: HFI_Skymap_353_full_bplcorrected_sm1deg_Qb.png | '''Full mission Q, 353 GHz'''<br />
</gallery><br />
</center><br />
<br><br />
<center><br />
<gallery style="padding:0 0 0 0;" perrow=3 widths=260px heights=160px> <br />
File: LFI_SkyMap_030_1024_R2.01_full_Ub_sm1deg.png| '''Full mission U, 30 GHz'''<br />
File: LFI_SkyMap_044_1024_R2.01_full_Ub_sm1deg.png | '''Full mission U, 44 GHz'''<br />
File: LFI_SkyMap_070_1024_R2.01_full_Ub_sm1deg.png | '''Full mission U, 70 GHz'''<br />
File: HFI_Skymap_100_full_bplcorrected_sm1deg_Ub.png | '''Full mission U, 100 GHz'''<br />
File: HFI_Skymap_143_full_bplcorrected_sm1deg_Ub.png | '''Full mission U, 143 GHz'''<br />
File: HFI_Skymap_217_full_bplcorrected_sm1deg_Ub.png | '''Full mission U, 217 GHz'''<br />
File: HFI_Skymap_353_full_bplcorrected_sm1deg_Ub.png | '''Full mission U, 353 GHz'''<br />
</gallery><br />
<br />
</center><br />
<br />
''' Full mission light maps, full channel maps (6 HFI, 7 LFI) '''<br />
<br />
These maps are based on the Full mission maps but contain fewer columns, IQU from 30 to 353 GHz, and I only at 545 and 857 GHz. These maps have been produced to reduce the transfer time of the most downloaded frequency full mission maps.<br />
<br />
''' Nominal mission, full channel maps (6 HFI) '''<br />
<br />
These maps are similar to the ones above, but cover the nominal mission only. They are meant primarily to be compared to the PR1 products in order to see the level of improvements in the processing. Because of this, they are produced in Temperature only, and have not had the post-processing applied.<br />
<br />
''' Single survey, full channel maps (30 HFI, 35 LFI)'''<br />
<br />
Single survey maps are built using all valid detectors of a frequency channel; they cover separately the different sky surveys. The surveys are defined as the times over which the satellite spin axis rotates but 180 degrees, which, due to the position of the detectors in the focal plane does not cover the full sky, but a fraction between ~80 and 90% depending on detector position. During adjacent surveys the sky is scanned in opposite directions. More precisely it is the ecliptic equator that is scanned in opposite directions. While these are useful to investigate variable sources, they are also used to study the systematics of the time-response of the detectors as they scan bright sources, like the Galactic Plane, in different directions during different survey. Note that the HFI and LFI missions cover 5 and 8 surveys, respectively, and in case of HFI the last survey in incomplete.<br />
The 70 GHz surveys maps are available also at <math>N_{side}</math> 2048.<br />
Note LFI provide a special surveys maps combination used in the low l analysis. This maps, available at the three LFI frequency 30, 44 and 70 GHz, was built using the combination of survey 1, 3, 5, 6, 7 and 8. <br />
<br />
''' Year maps, full channel maps (12 HFI, 16 LFI)'''<br />
<br />
These maps are built using the data of surveys 1+2, surveys 3+4, and so forth. They are used to study long-term systematic effects.<br />
The 70 GHz years maps are available also at <math>N_{side}</math> 2048.<br />
<br />
'''Half-mission maps, full channel maps (12 HFI, 12 LFI)'''<br />
<br />
For HFI, the half mission is defined after eliminating those rings discarded for all bolometers. There are 347 such rings, may of which are during the 5th survey when the ''End-of-Life'' tests were performed. The remaining 26419 rings are divided in half (up to the odd ring) to define the two halves of the mission. This exercise is done for the full mission only.<br />
<br />
For LFI instead of the half-mission the following year combination has been created: Year 1+2, Year 1+3, Year 2+4, Year 3+4, <br />
<br />
'''Full mission, single detector maps (18 HFI, 22 LFI)'''<br />
<br />
IN case of HFI these maps are built only for the SWBs (non polarized) and contain only temperature data, of course. They are not built for the polarisation sensitive detectors because they are not fixed on the sky as the polarisation component depends on the position angle at the time of observation. Instead, we provide maps built by ''quads'' of polarisation-sensitive detectors (see next section), which have different polarisation angles and that can be used to built I, Q, and U maps<br />
<br />
{| border="1" cellpadding="3" cellspacing="0" align="center" style="text-align:left" width=600px<br />
|+ '''HFI Temperature sensitive bolometers'''<br />
|- bgcolor="ffdead" <br />
!Frequency || Detector names<br />
|-<br />
|143 GHz || 143-5, 6, 7<br />
|-<br />
|217 GHz || 217-1, 2, 3, 4<br />
|-<br />
|353 GHz || 353-1, 2, 7, 8<br />
|-<br />
|545 GHz || 545-1, 2, 4<br />
|-<br />
|857 GHz || 857-1, 2 , 3, 4<br />
|}<br />
<br />
The 143-8 and 353-3 bolometer data are affected by strong RTS (random telegraphic signal) noise. They have not been used in the data processing, and are not delivered. For a figure showing the focal plane layout, see [[Detector_pointing#Introduction_and_Summary | this Introduction]] of the Detector Pointing chapter.<br />
<br />
In case of LFI, all the 22 Radiometers maps are available, those, obviously, are only in temperature.<br />
<br />
'''Full mission, detector set or detector pairs maps (8 HFI, 8 LFI)'''<br />
<br />
The objective here is to build independent temperature (I) and polarisation (Q and U) maps with the two pairs of polarisation sensitive detectors of each channel where they are available, i.e. in the 44-353 GHz channels. The table below indicates which detectors were used to built each detector set (detset).<br />
<br />
<br />
{| border="1" cellpadding="3" cellspacing="0" align="center" style="text-align:left" width=600px<br />
|+ '''Definition of HFI Detector Sets'''<br />
|- bgcolor="ffdead" <br />
!Frequency || DetSet1 || DetSet2 <br />
|-<br />
|100 GHz || 100-1a/b & 100-4a/b || 100-2a/b & 100-3a/b<br />
|-<br />
|143 GHz || 143-1a/b 1 & 43-3a/b || 143-2a/b & 143-4a/b<br />
|-<br />
|217 GHz || 217-5a/b & 217-7a/b || 217-6a/b & 217-8a/b<br />
|-<br />
|353 GHz || 353-3a/b & 353-5a/b || 353-4a/b & 353-6a/b<br />
|}<br />
<br />
{| border="1" cellpadding="3" cellspacing="0" align="center" style="text-align:left" width=600px<br />
|+ '''Definition of LFI Detector Pairs'''<br />
|- bgcolor="ffdead" <br />
!Frequency || Horn Pair || Comment <br />
|-<br />
|44 GHz || 24 || This maps is only in temperature<br />
|-<br />
|44 GHz || 25 & 26 || <br />
|-<br />
|70 GHz || 18 & 23 || Available also at <math>N_{side}</math> = 2048<br />
|-<br />
|70 GHz || 19 & 22 || Available also at <math>N_{side}</math> = 2048<br />
|-<br />
|70 GHz || 20 & 21 || Available also at <math>N_{side}</math> = 2048<br />
|}<br />
<br />
<br />
'''Half-ring maps (64 HFI, 62 LFI)'''<br />
<br />
These maps are similar to the ones above, but are built using only the first or the second half of each ring (or pointing period). The HFI provides half-ring maps for the full mission only, and for the full channel, the detsets, and the single bolometers. The LFI provides half-rings maps for the channel full mission (70 GHz also at <math>N_{side}</math> 2048), for the radiometer full mission and the horn pairs full mission.<br />
<!----<br />
'''Masks'''<br />
<br />
Masks are provided of the Galactic Plane and of the point sources. For the Galactic Plane, eight masks are given covering different fractions of the sky, and for the points sources two masks are given, at the 5 and 10 sigma level, for each Planck HFI and LFI frequency channel. These are generic masks, specific masks applicable to other products are delivered with the products themselves.<br />
---><br />
<br />
''' The Zodiacal light correction maps '''<br />
<br />
The Zodiacal light signal depends on the location of the observer relative to the Zodiacal light bands, and thus it is not a fixed pattern on the sky but depends on the period of observation. The maps presented here are the difference between the uncorrected (and not delivered) and the corrected maps. <br />
<br />
Note that while the Zodiacal light model that is subtracted at ring level (see [[Map-making#Zodiacal_light_correction | here]]) is not polarised, the corrections are not null and Q and U. This is suspected to come from some combination of leakage due to bandpass differences and beam mismatch, and maybe other effects. These leakages are typically of order a few %, at max, of the maximum zodi intensity at I for each channel. They range from ~150 nK at 100 GHz to ~5 uK at 353 GHz.<br />
<br />
''' Caveats and known issues '''<br />
<br />
; HFI polarization 100-217 GHz : at low multipoles, despite the progress that has been made to control the systematic effects present in the maps, polarization data between 100-217 GHz are still contaminated by systematic residuals. Figure 10 of {{PlanckPapers|planck2014-a09}} shows the EE power spectra from the half-difference maps at 100, 143, and 217 GHz and compared to the noise power spectrum from FFP8 simulations. he half-ring differences are compatible with noise while, at multipoles typically lower than 50, detector-set and half-mission differences are dominated by excess power which is larger than the EE CMB signal. The Planck Collaboration has used the range ell>30 to carry out component separation ({{PlanckPapers|planck2014-a11}}), as data at ell<30 is not considered usable for cosmological analyses. The origin of the excess power will be explored in a forthcoming publication.<br />
<br />
<br />
'''Inputs'''<br />
''' HFI inputs '''<br />
<br />
The HFI mapmaking takes as input:<br />
* the cleaned TOIs of signal of each detector, together with their flags, produced by the [[TOI processing|TOI processing]] pipeline;<br />
* the TOIs of pointing (quaternions), described in [[Detector_pointing|Detector pointing]];<br />
* bolometer-level characterization data, from the DPC's internal IMO (not distributed);<br />
* Planck orbit data, used to compute and remove the Earth's dipole;<br />
* Planck solar dipole information, used to calibrate the CMB channels;<br />
* Planet models used to calibrate the Galactic channels.<br />
<br />
''' LFI inputs '''<br />
<br />
The Madam mapmaker takes as input:<br />
<br />
* the calibrated timelines (for details see [[TOI processing LFI|TOI Processing]]);<br />
* the detector pointings (for details see [[Detector_pointing|Detector pointing]]);<br />
* the noise information in the form of 3-parameter (white noise level, &sigma;, slope, and knee frequency, <i>f</i><sub>knee</sub>) noise model (for details see [[The RIMO|RIMO]])<br />
<br />
'''Related products'''<br />
''' Masks '''<br />
<br />
This section presents the masks of the point sources and of the Galactic plane. These are ''general purpose'' masks. Other masks specific to certain products are packaged with the products.<br />
<br />
'''Point source masks'''<br />
<br />
For HFI and LFI two sets of masks are provided: <br />
* Intensity masks, which removes sources detected with SNR > 5. <br />
* Polarisation masks, which remove sources which have polarisation detection significance of 99.97 % or greater at the position of a source detected in intensity. They were derived from the polarisation maps with dust ground bandpass mismatch leakage correction applied. The cut around each source has a radius of 3σ (width) of the beam ~ 1.27 FWHM (for LFI the cut around each source has a radius of 32 arcmin at 30GHz, 27 arcmin at 44 GHz and 13 arcmin at 70 GHz).<br />
<br />
Both sets are found in the files ''HFI_Mask_PointSrc_2048_R2.00.fits'' and ''LFI_Mask_PointSrc_2048_R2.00.fits'' in which the first extension contains the Intensity masks, and the second contains the Polarisation masks.<br />
<br />
'''Galactic plane masks'''<br />
<br />
Eight masks are provided giving 20, 40, 60, 70, 80, 90, 97, and 99% sky coverage derived from the 353 GHz map, after CMB subtraction. They are independent of frequency channel. Three versions of these are given: not apodized, and apodized by 2 and 5 deg. The filenames are ''HFI_Mask_GalPlane-apoN_2048_R2.00.fits'', where N = 0, 2, 5.<br />
<br />
The masks are shows below. The 8 GalPlane masks are combined (added together) and shown in a single figure for each of the three apodization. While the result is quite clear for the case of no apodization, it is less so for the apodized case. The point source masks are shown separately for the Intensity case.<br />
<br />
<center><br />
<gallery perrow=3 widths=260px heights=160px ><br />
File: GalPlaneMask_apo0.png | '''Galactic Plane masks, no apod'''<br />
File: GalPlaneMask_apo2.png | '''Galactic Plane masks, apod 2 deg'''<br />
File: GalPlaneMask_apo5.png | '''Galactic Plane masks, apod 5 deg'''<br />
File: PointSrcMask_100.png | '''PointSource mask 100 GHz'''<br />
File: PointSrcMask_143.png | '''PointSource mask 143 GHz'''<br />
File: PointSrcMask_217.png | '''PointSource mask 217 GHz'''<br />
File: PointSrcMask_353.png | '''PointSource mask 343 GHz'''<br />
File: PointSrcMask_545.png | '''PointSource mask 545 GHz'''<br />
File: PointSrcMask_857.png | '''PointSource mask 857 GHz'''<br />
</gallery><br />
</center><br />
<br />
''' File names '''<br />
The FITS filenames are of the form ''{H|L}FI_SkyMap_fff{-tag}_Nside_R2.nn_{coverage}-{type}.fits'', where ''fff'' are three digits to indicate the Planck frequency band, ''tag'' indicates the single detector or the detset, ''Nside'' is the Healpix Nside of the map, ''coverage'' indicates which part of the mission is covered (full, half mission, survey, year, ...) , and the optional ''type'' indicates the subset of input data used. The table below lists the products by type, with the appropriate unix wildcards that form the full filename.<br />
<br />
{| class="wikitable" align="center" style="text-align"left" border="1" cellpadding="15" cellspacing="20" width=880px<br />
|+ '''HFI FITS filenames'''<br />
|- bgcolor="ffdead"<br />
! Coverage || filename || half-ring filename <br />
|-<br />
| Full chan, full mission ||HFI_SkyMap_???_2048_R2.??_full.fits ||HFI_SkyMap_???_2048_R2.??_full-ringhalf-?.fits<br />
|-<br />
| Full channel, nominal mission ||HFI_SkyMap_???_2048_R2.??_nominal.fits || n/a<br />
|-<br />
| Full channel, single survey || HFI_SkyMap_???_2048_R2.??_survey-?.fits || n/a<br />
|-<br />
| Full channel, single year || HFI_SkyMap_???_2048_R2.??_year-?.fits || n/a<br />
|-<br />
| Full channel, half mission || HFI_SkyMap_???_2048_R2.??_halfmission*-?.fits || n/a<br />
|-<br />
| Det-set, full mission || HFI_SkyMap_???-ds?_2048_R2.??_full.fits || HFI_SkyMap_???-ds?_2048_R2.??_full-ringhalf-?.fits<br />
|-<br />
|Single SWB, full mission || HFI_SkyMap_???-?_2048_R2.??_full.fits || HFI_SkyMap_???-?_2048_R2.??_full-ringhalf-?.fits<br />
|}<br />
<br />
{| class="wikitable" align="center" style="text-align"left" border="1" cellpadding="15" cellspacing="20" width=1000px<br />
|+ '''LFI FITS filenames'''<br />
|- bgcolor="ffdead"<br />
! Coverage || filename || half-ring filename || Comment<br />
|-<br />
| Full channel, full mission ||LFI_SkyMap_???_1024_R2.??_full.fits ||LFI_SkyMap_???_1024_R2.??_full-ringhalf-?.fits || Available also at Nside = 2048<br />
|-<br />
| Full channel, single survey || LFI_SkyMap_???_1024_R2.??_survey-?.fits || n/a || Available also at Nside = 2048<br />
|-<br />
| Full channel, survey combination || LFI_SkyMap_???_1024_R2.??_survey-1-3-5-6-7-8.fits || n/a || n/a<br />
|-<br />
| Full channel, single year || LFI_SkyMap_???_1024_R2.??_year-?.fits || n/a || Available also at Nside = 2048<br />
|-<br />
| Full channel, year combination || LFI_SkyMap_???_1024_R2.??_year?-?.fits || n/a || n/a<br />
|-<br />
| Horn pair, full mission || LFI_SkyMap_???-??-??_1024_R2.??_full.fits || LFI_SkyMap_???_??-??_1024_R2.??_full-ringhalf-?.fits || Available also at Nside = 2048<br />
|-<br />
| Single radiometer, full mission || LFI_SkyMap_???-???_1024_R2.??_full.fits || LFI_SkyMap_???-???_1024_R2.??_full-ringhalf-?.fits || n/a<br />
|}<br />
<br />
<br />
<br />
For the benefit of users who are only looking for the frequency maps with no additional information, we also provide a file combining the 9 frequency maps as separate columns in a single extension. The 9 columns in this file contain the intensity maps ONLY and no other information (hit maps and variance maps) is provided.<br />
<br />
<!---<br />
{| class="wikitable" align="center" style="text-align:center" border="1" cellpadding="3" cellspacing="0" width=500px<br />
|+ '''FITS filenames'''<br />
|- bgcolor="ffdead"<br />
! Frequency || Full channel maps<br />
|-<br />
| '''30GHz''' || {{PLASingleFile|fileType=map|name=LFI_SkyMap_030_1024_R1.10_nominal.fits|link=LFI_SkyMap_030_1024_R1.10_nominal.fits}}<br />
|-<br />
| '''44GHz''' || {{PLASingleFile|fileType=map|name=LFI_SkyMap_044_1024_R1.10_nominal.fits|link=LFI_SkyMap_044_1024_R1.10_nominal.fits}}<br />
|-<br />
| '''70GHz''' || {{PLASingleFile|fileType=map|name=LFI_SkyMap_070_1024_R1.10_nominal.fits|link=LFI_SkyMap_070_1024_R1.10_nominal.fits}}<br />
|-<br />
| '''70GHz''' || {{PLASingleFile|fileType=map|name=LFI_SkyMap_070_2048_R1.10_nominal.fits|link=LFI_SkyMap_070_2048_R1.10_nominal.fits}}<br />
|-<br />
| '''100GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_100_2048_R1.10_nominal.fits|link=HFI_SkyMap_100_2048_R1.10_nominal.fits}}<br />
|-<br />
| '''143GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_143_2048_R1.10_nominal.fits|link=HFI_SkyMap_143_2048_R1.10_nominal.fits}}<br />
|-<br />
| '''217GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_217_2048_R1.10_nominal.fits|link=HFI_SkyMap_217_2048_R1.10_nominal.fits}}<br />
|-<br />
| '''353GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_353_2048_R1.10_nominal.fits|link=HFI_SkyMap_353_2048_R1.10_nominal.fits}}<br />
|-<br />
| '''545GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_545_2048_R1.10_nominal.fits|link=HFI_SkyMap_545_2048_R1.10_nominal.fits}}<br />
|-<br />
| '''857GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_857_2048_R1.10_nominal.fits|link=HFI_SkyMap_857_2048_R1.10_nominal.fits}}<br />
|- bgcolor="ffdead"<br />
! Frequency || Full channel, Zodi-corrected maps<br />
|-<br />
| '''100GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_100_2048_R1.10_nominal_ZodiCorrected.fits|link=HFI_SkyMap_100_2048_R1.10_nominal_ZodiCorrected.fits}} <br />
|-<br />
| '''143GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_143_2048_R1.10_nominal_ZodiCorrected.fits|link=HFI_SkyMap_143_2048_R1.10_nominal_ZodiCorrected.fits}}<br />
|-<br />
| '''217GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_217_2048_R1.10_nominal_ZodiCorrected.fits|link=HFI_SkyMap_217_2048_R1.10_nominal_ZodiCorrected.fits}}<br />
|-<br />
| '''353GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_353_2048_R1.10_nominal_ZodiCorrected.fits|link=HFI_SkyMap_353_2048_R1.10_nominal_ZodiCorrected.fits}}<br />
|-<br />
| '''545GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_545_2048_R1.10_nominal_ZodiCorrected.fits|link=HFI_SkyMap_545_2048_R1.10_nominal_ZodiCorrected.fits}}<br />
|-<br />
| '''857GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_857_2048_R1.10_nominal_ZodiCorrected.fits|link=HFI_SkyMap_857_2048_R1.10_nominal_ZodiCorrected.fits}}<br />
|- bgcolor="ffdead"<br />
! Frequency || Combined frequency maps<br />
|-<br />
| '''All''' || {{PLASingleFile|fileType=file|name=COM_MapSet_I-allFreqs_R1.10_nominal.fits|link=COM_MapSet_I-allFreqs_R1.10_nominal.fits}} <br />
|}<br />
<br />
<br />
{| class="wikitable" align="center" style="text-align:center" border="1" cellpadding="3" cellspacing="0" width=850px<br />
|+ '''FITS filenames'''<br />
|- bgcolor="ffdead"<br />
! Frequency || Survey 1 maps || Survey 2 maps<br />
|-<br />
| '''30GHz''' || {{PLASingleFile|fileType=map|name=LFI_SkyMap_030_1024_R1.10_survey_1.fits|link=LFI_SkyMap_030_1024_R1.10_survey_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=LFI_SkyMap_030_1024_R1.10_survey_2.fits|link=LFI_SkyMap_030_1024_R1.10_survey_2.fits}}<br />
|-<br />
| '''44GHz''' || {{PLASingleFile|fileType=map|name=LFI_SkyMap_044_1024_R1.10_survey_1.fits|link=LFI_SkyMap_044_1024_R1.10_survey_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=LFI_SkyMap_044_1024_R1.10_survey_2.fits|link=LFI_SkyMap_044_1024_R1.10_survey_2.fits}}<br />
|-<br />
| '''70GHz''' || {{PLASingleFile|fileType=map|name=LFI_SkyMap_070_1024_R1.10_survey_1.fits|link=LFI_SkyMap_070_1024_R1.10_survey_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=LFI_SkyMap_070_1024_R1.10_survey_2.fits|link=LFI_SkyMap_070_1024_R1.10_survey_2.fits}}<br />
|-<br />
| '''70GHz''' || {{PLASingleFile|fileType=map|name=LFI_SkyMap_070_2048_R1.10_survey_1.fits|link=LFI_SkyMap_070_2048_R1.10_survey_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=LFI_SkyMap_070_2048_R1.10_survey_2.fits|link=LFI_SkyMap_070_2048_R1.10_survey_2.fits}}<br />
|-<br />
| '''100GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_100_2048_R1.10_survey_1.fits|link=HFI_SkyMap_100_2048_R1.10_survey_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_100_2048_R1.10_survey_2.fits|link=HFI_SkyMap_100_2048_R1.10_survey_2.fits}}<br />
|-<br />
| '''143GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_143_2048_R1.10_survey_1.fits|link=HFI_SkyMap_143_2048_R1.10_survey_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_143_2048_R1.10_survey_2.fits|link=HFI_SkyMap_143_2048_R1.10_survey_2.fits}}<br />
|-<br />
| '''217GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_217_2048_R1.10_survey_1.fits|link=HFI_SkyMap_217_2048_R1.10_survey_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_217_2048_R1.10_survey_2.fits|link=HFI_SkyMap_217_2048_R1.10_survey_2.fits}}<br />
|-<br />
| '''353GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_353_2048_R1.10_survey_1.fits|link=HFI_SkyMap_353_2048_R1.10_survey_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_353_2048_R1.10_survey_2.fits|link=HFI_SkyMap_353_2048_R1.10_survey_2.fits}}<br />
|-<br />
| '''545GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_545_2048_R1.10_survey_1.fits|link=HFI_SkyMap_545_2048_R1.10_survey_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_545_2048_R1.10_survey_2.fits|link=HFI_SkyMap_545_2048_R1.10_survey_2.fits}}<br />
|-<br />
| '''857GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_857_2048_R1.10_survey_1.fits|link=HFI_SkyMap_857_2048_R1.10_survey_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_857_2048_R1.10_survey_2.fits|link=HFI_SkyMap_857_2048_R1.10_survey_2.fits}}<br />
|- bgcolor="ffdead"<br />
! Frequency || Survey 1 Zodi-corrected maps || Survey 2 Zodi-corrected maps<br />
|-<br />
| '''100GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_100_2048_R1.10_survey_1_ZodiCorrected.fits|link=HFI_SkyMap_100_2048_R1.10_survey_1_ZodiCorrected.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_100_2048_R1.10_survey_2_ZodiCorrected.fits|link=HFI_SkyMap_100_2048_R1.10_survey_2_ZodiCorrected.fits}}<br />
|-<br />
| '''143GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_143_2048_R1.10_survey_1_ZodiCorrected.fits|link=HFI_SkyMap_143_2048_R1.10_survey_1_ZodiCorrected.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_143_2048_R1.10_survey_2_ZodiCorrected.fits|link=HFI_SkyMap_143_2048_R1.10_survey_2_ZodiCorrected.fits}}<br />
|-<br />
| '''217GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_217_2048_R1.10_survey_1_ZodiCorrected.fits|link=HFI_SkyMap_217_2048_R1.10_survey_1_ZodiCorrected.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_217_2048_R1.10_survey_2_ZodiCorrected.fits|link=HFI_SkyMap_217_2048_R1.10_survey_2_ZodiCorrected.fits}}<br />
|-<br />
| '''353GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_353_2048_R1.10_survey_1_ZodiCorrected.fits|link=HFI_SkyMap_353_2048_R1.10_survey_1_ZodiCorrected.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_353_2048_R1.10_survey_2_ZodiCorrected.fits|link=HFI_SkyMap_353_2048_R1.10_survey_2_ZodiCorrected.fits}}<br />
|-<br />
| '''545GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_545_2048_R1.10_survey_1_ZodiCorrected.fits|link=HFI_SkyMap_545_2048_R1.10_survey_1_ZodiCorrected.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_545_2048_R1.10_survey_2_ZodiCorrected.fits|link=HFI_SkyMap_545_2048_R1.10_survey_2_ZodiCorrected.fits}}<br />
|-<br />
| '''857GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_857_2048_R1.10_survey_1_ZodiCorrected.fits|link=HFI_SkyMap_857_2048_R1.10_survey_1_ZodiCorrected.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_857_2048_R1.10_survey_2_ZodiCorrected.fits|link=HFI_SkyMap_857_2048_R1.10_survey_2_ZodiCorrected.fits}}<br />
|- bgcolor="ffdead"<br />
! Frequency || Half-ring 1 maps ||Half-ring 2 maps<br />
|-<br />
| '''30GHz''' || {{PLASingleFile|fileType=map|name=LFI_SkyMap_030_1024_R1.10_nominal_ringhalf_1.fits|link=LFI_SkyMap_030_1024_R1.10_nominal_ringhalf_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=LFI_SkyMap_030_1024_R1.10_nominal_ringhalf_2.fits|link=LFI_SkyMap_030_1024_R1.10_nominal_ringhalf_2.fits}}<br />
|-<br />
| '''44GHz''' || {{PLASingleFile|fileType=map|name=LFI_SkyMap_044_1024_R1.10_nominal_ringhalf_1.fits|link=LFI_SkyMap_044_1024_R1.10_nominal_ringhalf_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=LFI_SkyMap_044_1024_R1.10_nominal_ringhalf_2.fits|link=LFI_SkyMap_044_1024_R1.10_nominal_ringhalf_2.fits}}<br />
|-<br />
| '''70GHz''' || {{PLASingleFile|fileType=map|name=LFI_SkyMap_070_1024_R1.10_nominal_ringhalf_1.fits|link=LFI_SkyMap_070_1024_R1.10_nominal_ringhalf_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=LFI_SkyMap_070_1024_R1.10_nominal_ringhalf_2.fits|link=LFI_SkyMap_070_1024_R1.10_nominal_ringhalf_2.fits}}<br />
|-<br />
| '''70GHz''' || {{PLASingleFile|fileType=map|name=LFI_SkyMap_070_2048_R1.10_nominal_ringhalf_1.fits|link=LFI_SkyMap_070_2048_R1.10_nominal_ringhalf_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=LFI_SkyMap_070_2048_R1.10_nominal_ringhalf_2.fits|link=LFI_SkyMap_070_2048_R1.10_nominal_ringhalf_2.fits}}<br />
|-<br />
| '''100GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_100_2048_R1.10_nominal_ringhalf_1.fits|link=HFI_SkyMap_100_2048_R1.10_nominal_ringhalf_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_100_2048_R1.10_nominal_ringhalf_2.fits|link=HFI_SkyMap_100_2048_R1.10_nominal_ringhalf_2.fits}}<br />
|-<br />
| '''143GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_143_2048_R1.10_nominal_ringhalf_1.fits|link=HFI_SkyMap_143_2048_R1.10_nominal_ringhalf_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_143_2048_R1.10_nominal_ringhalf_2.fits|link=HFI_SkyMap_143_2048_R1.10_nominal_ringhalf_2.fits}}<br />
|-<br />
| '''217GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_217_2048_R1.10_nominal_ringhalf_1.fits|link=HFI_SkyMap_217_2048_R1.10_nominal_ringhalf_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_217_2048_R1.10_nominal_ringhalf_2.fits|link=HFI_SkyMap_217_2048_R1.10_nominal_ringhalf_2.fits}}<br />
|-<br />
| '''353GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_353_2048_R1.10_nominal_ringhalf_1.fits|link=HFI_SkyMap_353_2048_R1.10_nominal_ringhalf_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_353_2048_R1.10_nominal_ringhalf_2.fits|link=HFI_SkyMap_353_2048_R1.10_nominal_ringhalf_2.fits}}<br />
|-<br />
| '''545GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_545_2048_R1.10_nominal_ringhalf_1.fits|link=HFI_SkyMap_545_2048_R1.10_nominal_ringhalf_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_545_2048_R1.10_nominal_ringhalf_2.fits|link=HFI_SkyMap_545_2048_R1.10_nominal_ringhalf_2.fits}}<br />
|-<br />
| '''857GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_857_2048_R1.10_nominal_ringhalf_1.fits|link=HFI_SkyMap_857_2048_R1.10_nominal_ringhalf_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_857_2048_R1.10_nominal_ringhalf_2.fits|link=HFI_SkyMap_857_2048_R1.10_nominal_ringhalf_2.fits}}<br />
|}<br />
---><br />
<br />
''' FITS file structure '''<br />
<br />
The FITS files for the sky maps contain a minimal primary header with no data, and a ''BINTABLE'' extension (EXTENSION 1, EXTNAME = ''FREQ-MAP'') containing the data. The structure is shows schematically in the figure below. The ''FREQ-MAP'' extension contains a 3- or a 10-column table that contain the signal, hit-count and variance maps, all in Healpix format. The 3-column case is for intensity only maps, the 10-column case is for polarisation. The number of rows is the number of map pixels, which is Npix = 12 <math>N_{side}</math><sup>2</sup> for Healpix maps, where <math>N_{side}</math> = 1024 or 2048 for most the maps presented in this chapter.<br />
<br />
[[File:FITS_FreqMap.png | 550px | center | thumb | '''FITS file structure''']]<br />
<br />
Note that file sizes are ~0.6 GB for I-only maps and ~1.9 GB for I,Q,U maps at <math>N_{side}</math> 2048 and ~0.14 GB for I-only maps and ~0.45 GB for I,Q,U maps at <math>N_{side}</math> 1024 .<br />
<br />
Keywords indicate the coordinate system (GALACTIC), the Healpix ordering scheme (NESTED), the units (K_cmb or MJy/sr) of each column, and of course the frequency channel (FREQ). Where polarisation Q and U maps are provided, the ''COSMO'' polarisation convention (used in HEALPIX) is adopted, and it is specified in the ''POLCCONV'' keyword (see [[Sky_temperature_maps#Polarization_convention_used_in_the_Planck_project|this section]]. The COMMENT fields give a one-line summary of the product, and some other information useful for traceability within the DPCs. The original filename is also given in the ''FILENAME'' keyword. The ''BAD_DATA'' keyword gives the value used by Healpix to indicate pixels for which no signal is present (these will also have a hit-count value of 0). The main parameters are summarised below:<br />
<br />
<br />
{| border="1" cellpadding="3" cellspacing="0" align="center" style="text-align:left" width=800px<br />
|+ '''Sky map file data structure'''<br />
|- bgcolor="ffdead" <br />
!colspan="4" | 1. EXTNAME = 'FREQ-MAP' : Data columns<br />
|- bgcolor="ffdead" <br />
! Column Name || Data Type || Units || Description<br />
|-<br />
|I_STOKES || Real*4 || K_cmb or MJy/sr || The Stokes I map<br />
|-<br />
|Q_STOKES || Real*4 || K_cmb or MJy/sr || The Stokes Q map (optional)<br />
|-<br />
|U_STOKES || Real*4 || K_cmb or MJy/sr || The Stokes U map (optional)<br />
|-<br />
|HITS || Int*4 || none || The hit-count map<br />
|-<br />
|II_COV || Real*4 || K_cmb<sup>2</sup> or (MJy/sr)<sup>2</sup> || The II variance map<br />
|-<br />
|IQ_COV || Real*4 || K_cmb<sup>2</sup> or (MJy/sr)<sup>2</sup> || The IQ variance map (optional)<br />
|-<br />
|IU_COV || Real*4 || K_cmb<sup>2</sup> or (MJy/sr)<sup>2</sup> || The IQ variance map (optional)<br />
|-<br />
|QQ_COV || Real*4 || K_cmb<sup>2</sup> or (MJy/sr)<sup>2</sup> || The QQ variance map (optional)<br />
|-<br />
|QU_COV || Real*4 || K_cmb<sup>2</sup> or (MJy/sr)<sup>2</sup> || The QU variance map (optional)<br />
|-<br />
|UU_COV || Real*4 || K_cmb<sup>2</sup> or (MJy/sr)<sup>2</sup> || The UU variance map (optional)<br />
|-<br />
|- bgcolor="ffdead" <br />
! Keyword || Data Type || Value || Description<br />
|-<br />
|PIXTYPE || string || HEALPIX ||<br />
|-<br />
|COORDSYS || string || GALACTIC ||Coordinate system <br />
|-<br />
|ORDERING || string || NESTED || Healpix ordering<br />
|-<br />
|POLCCONV || String || COSMO || Polarization convention<br />
|-<br />
|NSIDE || Int || 1024 or 2048 || Healpix <math>N_{side}</math> <br />
|-<br />
|FIRSTPIX || Int*4 || 0 || First pixel number<br />
|-<br />
|LASTPIX || Int*4 || 12 <math>N_{side}</math><sup>2</sup> – 1 || Last pixel number<br />
|-<br />
|FREQ || string || nnn || The frequency channel <br />
|}<br />
<br />
<br />
The same structure applies to all ''SkyMap'' products, independent of whether they are full channel, survey of half-ring. The distinction between the types of maps is present in the FITS filename (and in the traceability comment fields).<br />
<br />
'''Polarization convention used in the Planck project'''<br />
<br />
The Planck collaboration used the COSMO convention for the polarization angle (as usually used in space based CMB missions), whereas other astronomical fields usually use the IAU convention. In the following document we report the difference between these two conventions, and the consequence if it is NOT taken into account correctly in the analysis.<br />
<br />
[[File:conventions.png|thumb|center|400px|'''Figure 1. COSMO convention (left) and IAU convention (right). The versor <math>\hat{z}</math> points outwards the pointing direction in COSMO, and inwards in IAU. The bottom panel refers to the plane tangent to the sphere.''']]<br />
<br />
Changing the orientation convention is equivalent to a transformation <math>\psi'=\pi-\psi</math> of the polarization angle (Figure 1). The consequence of this transformation is the inversion of the Stokes parameter <math>U</math>.<br />
The components of the polarization tensor in the helicity basis <math>\epsilon^{\pm}=1/\sqrt{2}(\hat{x}\pm i\hat{y})</math> are:<br />
<br />
<math><br />
(Q+iU)(\hat{n}) = \sum _{\ell m}a_{2,lm}{}_{2}Y_{\ell }^{m}(\hat{n})<br />
\\(Q-iU)(\hat{n}) = \sum _{\ell m}a_{-2,lm}{}_{2}Y_{\ell }^{m}(\hat{n})<br />
</math><br />
<br />
where <math>{}_{2}Y_{\ell }^{m}(\hat{n})</math> are the spin weighted spherical harmonic functions.<br />
The <math>E</math> and <math>B</math> modes can be defined as:<br />
<math><br />
E(\hat{n}) = \sum_{\ell m}a_{E,\ell m}Y_{\ell }^{m}(\hat{n})<br />
\\B(\hat{n}) = \sum_{\ell m}a_{B,\ell m}Y_{\ell }^{m}(\hat{n})<br />
</math><br />
<br />
where the coefficients <math>a_{E,\ell m}</math> and <math>a_{B,\ell m}</math> are derived from linear combinations of the <math>a_{2,\ell m}</math> , <math>a_{-2,\ell m}</math> defined implicitly in the first equation (<math>Q\pm iU</math>).<br />
<br />
[[File:test_gradient.jpg|thumb|center|400px|]]<br />
[[File:test_curl.jpg|thumb|center|400px|'''Figure 2. Error on Planck-LFI 70 GHz <math>EE</math> (top) and <math>BB</math> (bottom) spectra, in case of wrong choice of the coordinate system convention (IAU instead of COSMO).''']]<br />
<br />
The effect of the sign inversion of <math>U</math> on the polarization spectra is a non trivial mixing of <math>E</math> and <math>B</math> modes. <br />
<br />
An example of the typical error on <math>EE</math> and <math>BB</math> auto-spectra in case of a wrong choice of the polarization basis is shown in Figure 2.<br />
<br />
BE CAREFUL about the polarization convention you are using. If the IAU convention is used in computing the power spectra, the sign of the <math>U</math> component of the Planck maps must be inverted before computing <math>E</math> and <math>B</math> modes.<br />
<br />
''' Note on the convention used by the Planck Catalogue of Compact Sources (PCCS) '''<br />
For continuity with other compact sources catolgues, the Catalogue of Compact Sources provided by Planck follows the IAU convention, and the polarization angles are defined on an interval of [-90&deg;,90&deg;]. To switch to the COSMO convention, the polarization angles listed in the catalogue have to be shifted by 90&deg; and multiplied by -1.<br />
<br />
== References ==<br />
<References /><br />
<br />
</div><br />
</div><br />
<br />
<div class="toccolours mw-collapsible mw-collapsed" style="background-color: #EEE8AA;width:80%" ><br />
'''2013 Sky temperature maps'''<br />
<br />
<div class="mw-collapsible-content"><br />
<br />
'''General description'''<br />
<br />
<br />
Sky maps give the best estimate of the intensity of the signal from the sky after removal, as far as possible, of known systematic effects and of the dipole signals induced by the motion of the solar system in the CMB and of the Planck satellite in the solar system. Sky maps are provided for the nominal Planck mission and also, separately, for the first two single surveys, the third one being covered only for a small part during the nominal mission.The details of the start and end times of each are given in [[HFIpreprocessingstatics | this table]]. As a secondary product, maps with estimates of the Zodiacal light and Far-Side-Lobes contribution removed are also provided. <br />
<br />
For characterization purposes, are also provided maps covering the nominal survey but each one using only half of the available data. These are the ''ringhalf_{1|2}'' maps, which are built using the first and second half of the stable pointing part in each pointing period. These maps are used extensively to investigate the (high frequency) noise properties the maps themselves and of other products described elsewhere (see e.g., the [[HFI-Validation | data validation]] section).<br />
<br />
To help in further processing, there are also masks of the Galactic Plane and of point sources, each provided for several different depths.<br />
<br />
All sky maps are in Healpix format, with Nside of 2048 for HFI and of 1024 for LFI (note that the LFI 70 GHz has been delivered also at Nside of 2048 to be directly comparable with HFI maps), in Galactic coordinates, and Nested ordering. The signal is given in units of K<sub>cmb</sub> for 30-353 GHz, and of MJy/sr (for a constant $\nu F_\nu$ energy distribution ) for 545 and 857 GHz. Each sky map is packaged into a ''BINTABLE'' extension of a FITS file together with a hit-count map (or hit map, for short, giving the number of observation samples that are cumulated in a pixel, all detectors combined) and a variance map (determined from the half-ring maps), and additional information is given in the FITS file header. The structure of the FITS file is given in the [[#Format | FITS file structure]] section below.<br />
<br />
<br />
'''Types of maps '''<br />
<br />
; Full channel maps<br />
: Full channel maps are built using all the valid detectors of a frequency channel and cover the nominal mission. For HFI, the 143-8 and 545-3 bolometers are rejected entirely as they are seriously affected by RTS noise. The maps are displayed in the figures below. The range is the same from 30 - 143 GHz in order to show the CMB at the same level. At higher frequencies the range is increased in order to keep the Galactic Plane from invading the whole sky.<br />
<br />
<center><br />
<gallery style="padding:0 0 0 0;" perrow=3 widths=260px heights=160px> <br />
File: SkyMap30.png| '''Nominal mission, 30 GHz'''<br />
File: SkyMap44.png | '''Nominal mission, 44 GHz'''<br />
File: SkyMap70.png | '''Nominal mission, 70 GHz'''<br />
File: SkyMap100.png | '''Nominal mission, 100 GHz'''<br />
File: SkyMap143.png | '''Nominal mission, 143 GHz'''<br />
File: SkyMap217.png | '''Nominal mission, 217 GHz'''<br />
File: SkyMap353.png | '''Nominal mission, 353 GHz'''<br />
File: SkyMap545.png | '''Nominal mission, 545 GHz'''<br />
File: SkyMap857.png | '''Nominal mission, 857 GHz'''<br />
</gallery><br />
</center><br />
<br />
; Single survey maps <br />
: Single survey maps are built using all valid detectors of a frequency channel; they cover separately the different sky surveys. The surveys are defined as the times over which the satellite spin axis rotates but 180 degrees, which, due to the position of the detectors in the focal plane does not cover the full sky, but a fraction between ~80 and 90% depending on detector position.<br />
<br />
; Detector set or detector pairs maps<br />
: These are maps built from a subset of the detectors in a frequency channel, typically our of two PSB pairs (i.e., four poloarisation-sensitive bolometers with different orientation on the sky), for HFI in order to extract a single temperature map. While none of these maps are part of the first Planck data release, the concept of ''detset'' is used, and thus it is worth mentioning it here. In particular, information by detector set is available at the [[Frequency_maps_angular_power_spectra | sky power spectrum]] level and in the [[The RIMO | RIMO]].<br />
<br />
; Half-ring maps<br />
: Half-ring maps are built using only the first or the second half of the stable pointing period data. There are thus two half-ring maps per frequency channel named ''ringhalf_1'' and ''ringhalf_2'' respectively. These maps are built for characterization purposes in order to perform null tests. In particular, the difference between the two half-ring maps at a given frequency give a good estimate of the high frequency noise in the data (albeit biased low by ~0.5% for the HFI channels due to specifics of the TOI processing).<br />
<br />
; Masks<br />
: Masks are provided of the Galactic Plane and of the point sources. For the Galactic Plane, eight masks are given covering different fractions of the sky, and for the points sources two masks are given, at the 5 and 10 sigma level, for each Planck HFI frequency channel. These are generic masks, specific masks applicable to other products are delivered with the products themselves.<br />
<br />
''' Caveats and known issues'''<br />
<br />
The primary limitation of the HFI maps are<br />
* the absence of correction of the ADC non-linearities,<br />
* the far-side lobe contribution is not accounted for in the processing and in the calibration,<br />
* the dipole removal is based on the non-relativistic approximation which leaves a weak quadrupole component in the map.<br />
And thus the overall calibration accuracy is at the 0.2% level in 100-217 GHz channels<br />
<br />
The LFI 70 GHz maps at Nside=2048 should be considered as additional product, the default are the LFI maps at Nside=1024. No effective beam at Nside=2048 is provided, only at Nside=1024, for this reason the use of the effective beam with maps at Nside 2048 is discouraged.<br />
<br />
''' Map zero-level '''<br />
<br />
For the 100 to 857 GHz maps, the zero levels are set to their optimal levels for Galactic and CIB studies. A procedure for adjusting them to astrophysical values is given in the HFI Calibration paper {{PlanckPapers|planck2013-p03b}}.<br />
<br />
For the 30, 44 and 70 GHz, maps are corrected for zero level monopole by applying an offset correction, see LFI Calibration paper {{PlanckPapers|planck2013-p02b}} section 3.4 "Setting the zero levels in the maps". Note that the offset applied is indicated in the header as a comment keyword.<br />
<br />
''' The Zodiacal light and the Far-Side Lobes '''<br />
<br />
The figures below show the modeled Zodiacal light and Far Side Lobes projected onto the maps; they are simply the difference between the ''main product'' and the ''ZodiCorrected'' maps for the nominal mission. The units are given in the figures. The ''heat'' color table has been used in place of the standard Planck for clarity reasons. <br />
<center><br />
<gallery perrow=3 widths=260px heights=170px><br />
File: ZodiRes100.png | '''zodi/FSL rediduals - 100 GHz'''<br />
File: ZodiRes143.png | '''zodi/FSL rediduals - 143 GHz''' <br />
File: ZodiRes217.png | '''zodi/FSL rediduals - 217 GHz'''<br />
File: ZodiRes353.png | '''zodi/FSL rediduals - 353 GHz'''<br />
File: ZodiRes545.png | '''zodi/FSL rediduals - 545 GHz'''<br />
File: ZodiRes857.png | '''zodi/FSL rediduals - 857 GHz'''<br />
</gallery><br />
</center><br />
The effects of the FSLs are seen most clearly at the highest frequencies, as structures roughly symmetric about the center of the image, which corresponds to the location of the Galactic Centre, which is in turn the source of most of the radiation that is scattered into the FSLs.<br />
<br />
''' Artifacts near caustics of the scanning strategy '''<br />
<br />
The [[Survey scanning and performance|scanning strategy]] is such that regions around the Ecliptic poles are surveyed very deeply and compared to the average, and the transition from the nominal depth to the high depth, as shows on hit-count maps is very rapid, namely a few pixels, for a contrast of ~30. These transitions, or caustics in the maps, occur at different positions on the sky for different detectors, as the positions depend on their location in the focal plane of the instrument. As a result, when data from different detectors are combined to build a full channel map, the the weights of different detectors in the mix changes rapidly across the caustic, and given the remaining errors in the relative calibration of the detectors, a visible effect can be introduced in the maps, especially when the SNR is very high, i.e. at the highest frequencies and near bright regions like the Galactic Plane. Some examples are shown below.<br />
<br />
<center><br />
<gallery perrow=3 heights=260px widths=260pix ><br />
File: causta857.png | '''857 GHz intensity map around (272.5, -27)'''<br />
File: caustb857.png | '''857 GHz intensity map around (264.5, -37.5)'''<br />
File: caustc857.png | '''857 GHz intensity map around (98.5, 43)'''<br />
File: hita857.png | '''857 GHz hit count map around (272.5, -27)'''<br />
File: hitb857.png | '''857 GHz hit count map around (264.5, -37.5)'''<br />
File: hitc857.png | '''857 GHz hit count map around (98.5, 43)'''<br />
</gallery><br />
</center><br />
<br />
'''Production process'''<br />
<br />
<br />
Sky maps are produced by combining appropriately the data of all working detectors in a frequency channel over some period of the mission. They give the best estimate of the signal from the sky (unpolarised) after removal, as far as possible, of known systematic effects and of the dipole signals induced by the motion of the solar system in the CMB and of the Planck satellite in the solar system. In particular, they include the Zodiacal light emission (Zodi for short) and also the scattering from the far-side lobes of the beams (FSL). More on this below.<br />
<br />
''' HFI processing '''<br />
<br />
The inputs to the mapmaking are TOIs of signal that have been cleaned (as far as possible) of instrumental effects and calibrated in absorbed watts. While the processing involved is described in detail in the [[TOI processing|TOI processing]] section, we give a very brief summary here for convenience. That pipeline performs the following operations:<br />
<br />
; demodulation: this is performed around a variable level which is determined from the valid input data (a validity flag from a previous version of the processing is used for this purpose), and the data are converted to engineering units (V) using known conversion coefficients.<br />
; despiking: using the demodulated data converted to V (by the transfer function) the glitches are identified and fitted with templates. A glitch flag is produced that identifies the strongest part of the glitches, and a timeline of glitch tails is produced from the template fits, and subtracted from the demodulated timeline from step 1. Finally, the flagged ranges are replaced with data from an average over the pointing period (TBC)<br />
; dark template removal: the two dark bolometers are demodulated and despiked as above; the resulting timelines are then smoothed and used as an indicator of the overall temperature variations of the bolometer plate. Where the variations are consistent with each other, they are combined and removed from the bolometer signal timelines using appropriate coupling coefficients. The few percent of the data where they are not consistent are flagged on the timelines.<br />
; conversion to absorbed power: the timeline is converted to watts of absorbed power using the bolometer function. This includes a non-linearity correction; removal of the 4K cooler lines: the electromagnetic interference of the 4K cooler with the bolometer readout wires induces some sharp lines in the signal power spectra at frequencies of the 4K cooler's fundamental and its multiples, folded by the signal modulations. Fourier coefficients of the relevant lines are determined on a per-ring basis, and then removed from the data. The quality of the removal depends on the bolometer.<br />
; deconvolution by the time transfer function: this is done to correct for the non-instantaneous time response of the bolometers. The function itself is modeled using 4 parameters which are adjusted primarily on the planet data and also from comparisons of the northward and southward scans of the Galactic Plane. It is then removed using Fourier techniques, which has the side-effect of increasing the noise at high frequencies.<br />
; jump correction: removes some (relatively rare: 0.3 jumps per bolometer per pointing period, on average) jumps in the signal baseline. The jumps are detected characterized on smoothed TOIs, and corrected by adding a constant to part of the signal timeline. The origin of the jumps is not known.<br />
<br />
The results of this processing are a timeline of signal (in absorbed watts) and a ''valid data'' flag timeline for each of the 50 valid bolometers processed; these timelines contain the full sky signal, i.e., including the solar and orbital dipoles, the Zodiacal light, and contributions from the Far-Side lobes. The dipoles are necessary for the flux calibration and are removed at the mapmaking stage. The remaining two bolometers (143-8 and 535-3) show semi-random jumps in the signal level, typically jumping over 2-5 different ''pseudo-baseline'' levels, a behavior known as ''Random Telegraphic Signal'', so that these are commonly called the RTS bolometers. Finally, ring-level statistics of different types (mean, median, rms, kurtosis, etc.) are determined on a per-ring basis for all timelines, and a selection based on these statistics is used to discard anomalous rings, which are recorded in a ring-level flag for each valid bolometer timeline (see the [[TOI_processing#Discarded_rings| Discarded rings]] section). <br />
<br />
Throughout this processing, bright planets (Mars, Jupiter, Saturn, Uranus) and bright asteroids are masked in the timeline in order to avoid ringing effects in the processing. Since they move on the sky, the portion of the sky masked during one survey is observed during one, and no hole is left in the final map. In parallel, the planet data are processed in a similar way, but with different parameters for the despiking step, and without the final jump correction step. These results are processed separately to determine the beam shapes and the focal plane geometry.<br />
<br />
The pointing is determined starting from the AHF produced by MOC, which gives the direction and orientation of the LOS of a fiducial position in the focal plane at frequencies of 8Hz during stable pointing and 4 Hz during maneuvers (TBC for details, reference). This is interpolated to the times of data observation (ref to method), corrected for the wobble and other time-dependent offsets determined from the observed positions of a large number of sources around the sky, and finally converted to the LOS of each detector using the quaternions in the IMO (which are determined from observations of bright planets - see the [[Detector_pointing]] section). <br />
<br />
The mapmaking and calibration process is described in detail in the [[Map-making_LFI | Map-making]] section, where detailed references are found. In brief it consists of:<br />
<br />
; binning the TOI data onto ''rings'' : Healpix rings (HPRs) are used here, each ring containing the combined data of one pointing period. <br />
; flux calibration : at 100-353 GHz, the flux calibration factors are determined for each pointing period (or ring) from the solar-motion dipole, using the WMAP dipole as the reference, and after removal of the dipole signal induced by the motion of the Planck satellite in the solar system. This gain by ring is smoothed with a window of width 50 rings, which reveals an apparent variation of ~1-2% on a scale of 100s to 1000s of rings for the 100-217 GHz channels, and is applied. At 353GHz, where the solar motion dipole is weaker compared to the signal, no gain variation is detected (within the uncertainties), and a single fixed gain is applied to all rings. At 545 and 857 GHz the gain is determined from the observation of Uranus and Neptune (but not Jupiter which is too bright) and comparison to recent models made explicitly for this mission. A single gain is applied to all rings at these frequencies.<br />
; destriping : in order to remove low-frequency noise, an offset per ring is determined by minimizing the differences between HPRs at their crossings, and removed.<br />
; projection onto the map : the offset-corrected and flux-calibrated HPRs are projected onto Healpix maps, with the data of each bolometer weighted by a factor of 1/NET of that bolometer, and accounting for the slight different band transmission profiles of the bolometers in each band. <br />
<br />
These maps provide the main mission products. A second, reduced, set of maps, cleaned of the Zodiacal emission of the FSL leakage is also produced for the nominal mission and the two single surveys, but not for the half-rings (since the contribution would be the same for the two halves of each ring). For this purpose, the the Zodiacal emission and the FSL contamination, which are not fixed on the sky, are modeled separately at HPR-level, and subtracted from the signal HPR before projecting them onto the maps. <br />
<br />
Together with signal maps, hit count and variance maps are also produced. The hit maps give the (integer) number of valid TOI-level samples that contribute to the signal of each pixel. All valid samples are counted in the same way, i.e., there is no weighting factor applied. The variance maps project the white noise estimate, provided by the NETs, in the sky domain.<br />
<br />
''' LFI processing '''<br />
<br />
LFI maps were constructed with the Madam map-making code, version 3.7.4. The code is based on generalized destriping technique, where the correlated noise component is modeled as a sequence of constant offset, called baselines. A noise filter was used to constrain the baseline solution allowing the use of 1 second baselines.<br />
<br />
Radiometers were combined according to the horn-uniform weighting scheme to minimize systematics. The used weights are listed in [[Map-making LFI#Map-making|Map-making]]. The flagged samples were excluded from the analysis by setting their weights to $C_{w}^{-1}$ = 0. The galaxy region was masked out in the destriping phase, to reduce error arising from strong signal gradients. The polarization component was included in the analysis, although only the temperature maps are released. <br />
<br />
A detailed description of the map-making procedure is given in {{PlanckPapers|planck2013-p02}} and in section [[Map-making LFI#Map-making|Map-making]].<br />
<br />
'''Inputs'''<br />
<br />
<br />
''' HFI inputs '''<br />
<br />
* The cleaned TOIs of signal of each detector, together with their flags, produced by the [[TOI processing|TOI processing]] pipeline<br />
* The TOIs of pointing (quaternions), described in [[Detector_pointing]]<br />
* Bolometer-level characterization data, from the DPC's internal IMO (not distributed)<br />
* Planck orbit data used to compute and remove the earth dipole<br />
* WMAP solar dipole information used to calibrate the CMB channels<br />
* Planet models used to calibrate the Galactic channels.<br />
<br />
''' LFI inputs '''<br />
<br />
The Madam map-maker takes as an input:<br />
<br />
* The calibrated timelines (for details see [[TOI processing LFI|TOI Processing]])<br />
* The detector pointings (for details see [[Detector pointing|Detector pointing]])<br />
* The noise information in the form of three-parameter (white noise level ($\sigma$), slope, and knee frequency ($f_\mathrm{knee}$)) noise model (for details see [[The RIMO|RIMO]])<br />
<br />
'''Related products'''<br />
<br />
<br />
''' Masks '''<br />
<br />
Masks are provided of<br />
<br />
; the point sources<br />
: 15 masks are provided, three for the LFI (one mask for each frequency masking at the 4<math>\sigma</math> level) and 12 for the HFI (two masks for each frequency at the 5 and 10<math>\sigma</math> levels. For the HFI the masks can be used as they are, for the LFI they need to be downgraded to Nside=1024 except for the 70 GHz channel at Nside=2048 which does not need to be downgraded.<br />
<br />
; the Galactic Plane<br />
: 8 masks are provided giving 20, 40, 60, 70, 80, 90, 97, and 99% sky coverage in two different files, at Nside=2048. For the HFI they can be used as they are, for the LFI they need to be downgraded at Nside=1024 (note that if using the 70 GHZ at Nside=2048 no downgraded is needed)<br />
<br />
<br />
The masks are binary, in GALACTIC coordinates, and NESTED ordering. The table below give the filenames. <br />
<br />
<br />
{| class="wikitable" align="center" style="text-align:center" border="1" cellpadding="5" cellspacing="0" <br />
|+ '''FITS filenames for masks'''<br />
|-bgcolor="ffdead"<br />
! Frequency || LFI Point Source masks<br />
|-<br />
| '''30GHz''' || {{PLASingleFile|fileType=map|name=LFI_MASK_030-ps_2048_R1.00.fits|link=LFI_MASK_030-ps_2048_R1.00.fits}}<br />
|-<br />
| '''44GHz''' || {{PLASingleFile|fileType=map|name=LFI_MASK_044-ps_2048_R1.00.fits|link=LFI_MASK_044-ps_2048_R1.00.fits}}<br />
|-<br />
| '''70GHz''' || {{PLASingleFile|fileType=map|name=LFI_MASK_070-ps_2048_R1.00.fits|link=LFI_MASK_070-ps_2048_R1.00.fits}}<br />
|- bgcolor="ffdead"<br />
! colspan="2" | HFI Point Source masks<br />
|-<br />
| colspan="2" | {{PLASingleFile|fileType=map|name=HFI_Mask_PointSrc_2048_R1.10.fits|link=HFI_Mask_PointSrc_2048_R1.10.fits}}<br />
|- bgcolor="ffdead"<br />
! colspan="2" | Galactic Plane masks<br />
|-<br />
| colspan="2" | {{PLASingleFile|fileType=map|name=HFI_Mask_GalPlane_2048_R1.10.fits|link=HFI_Mask_GalPlane_2048_R1.10.fits}} <br />
|}<br />
<br />
<br />
The masks are shows below in a single figure. While this is quite clear for the Galactic Plane masks, it is less so for the point source masks, but it does give a clear perspective on how the latter are distributed over the sky.<br />
<br />
<center><br />
<gallery perrow=2 widths=300px heights=185px ><br />
File: HFI_GalPlaneMask.png | '''Galactic Plane masks'''<br />
File: HFI_PointSrcMask.png | '''PointSource masks'''<br />
</gallery><br />
</center><br />
<br />
''' File names '''<br />
<br />
<br />
The FITS filenames are of the form ''{H|L}FI_SkyMap_fff_nnnn_R1.nn_{coverage}_{type}.fits'', where ''fff'' are three digits to indicate the Planck frequency band, and ''nnnn'' is the Healpix Nside of the map, ''coverage'' indicates which part of the mission is covered, and the optional ''type'' indicates the subset of input data used. A full list of products, with links to them in the Archive, is given in the tables below.<br />
<br />
For the benefit of users who are only looking for the frequency maps with no additional information, we also provide a file combining the 9 frequency maps as separate columns in a single extension. The 9 columns in this file contain the intensity maps ONLY and no other information (hit maps and variance maps) is provided.<br />
<br />
{| class="wikitable" align="center" style="text-align:center" border="1" cellpadding="5" cellspacing="0" width=500px<br />
|+ '''FITS filenames'''<br />
|- bgcolor="ffdead"<br />
! Frequency || Full channel maps<br />
|-<br />
| '''30GHz''' || {{PLASingleFile|fileType=map|name=LFI_SkyMap_030_1024_R1.10_nominal.fits|link=LFI_SkyMap_030_1024_R1.10_nominal.fits}}<br />
|-<br />
| '''44GHz''' || {{PLASingleFile|fileType=map|name=LFI_SkyMap_044_1024_R1.10_nominal.fits|link=LFI_SkyMap_044_1024_R1.10_nominal.fits}}<br />
|-<br />
| '''70GHz''' || {{PLASingleFile|fileType=map|name=LFI_SkyMap_070_1024_R1.10_nominal.fits|link=LFI_SkyMap_070_1024_R1.10_nominal.fits}}<br />
|-<br />
| '''70GHz''' || {{PLASingleFile|fileType=map|name=LFI_SkyMap_070_2048_R1.10_nominal.fits|link=LFI_SkyMap_070_2048_R1.10_nominal.fits}}<br />
|-<br />
| '''100GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_100_2048_R1.10_nominal.fits|link=HFI_SkyMap_100_2048_R1.10_nominal.fits}}<br />
|-<br />
| '''143GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_143_2048_R1.10_nominal.fits|link=HFI_SkyMap_143_2048_R1.10_nominal.fits}}<br />
|-<br />
| '''217GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_217_2048_R1.10_nominal.fits|link=HFI_SkyMap_217_2048_R1.10_nominal.fits}}<br />
|-<br />
| '''353GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_353_2048_R1.10_nominal.fits|link=HFI_SkyMap_353_2048_R1.10_nominal.fits}}<br />
|-<br />
| '''545GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_545_2048_R1.10_nominal.fits|link=HFI_SkyMap_545_2048_R1.10_nominal.fits}}<br />
|-<br />
| '''857GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_857_2048_R1.10_nominal.fits|link=HFI_SkyMap_857_2048_R1.10_nominal.fits}}<br />
|- bgcolor="ffdead"<br />
! Frequency || Full channel, Zodi-corrected maps<br />
|-<br />
| '''100GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_100_2048_R1.10_nominal_ZodiCorrected.fits|link=HFI_SkyMap_100_2048_R1.10_nominal_ZodiCorrected.fits}} <br />
|-<br />
| '''143GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_143_2048_R1.10_nominal_ZodiCorrected.fits|link=HFI_SkyMap_143_2048_R1.10_nominal_ZodiCorrected.fits}}<br />
|-<br />
| '''217GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_217_2048_R1.10_nominal_ZodiCorrected.fits|link=HFI_SkyMap_217_2048_R1.10_nominal_ZodiCorrected.fits}}<br />
|-<br />
| '''353GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_353_2048_R1.10_nominal_ZodiCorrected.fits|link=HFI_SkyMap_353_2048_R1.10_nominal_ZodiCorrected.fits}}<br />
|-<br />
| '''545GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_545_2048_R1.10_nominal_ZodiCorrected.fits|link=HFI_SkyMap_545_2048_R1.10_nominal_ZodiCorrected.fits}}<br />
|-<br />
| '''857GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_857_2048_R1.10_nominal_ZodiCorrected.fits|link=HFI_SkyMap_857_2048_R1.10_nominal_ZodiCorrected.fits}}<br />
|- bgcolor="ffdead"<br />
! Frequency || Combined frequency maps<br />
|-<br />
| '''All''' || {{PLASingleFile|fileType=file|name=COM_MapSet_I-allFreqs_R1.10_nominal.fits|link=COM_MapSet_I-allFreqs_R1.10_nominal.fits}} <br />
|}<br />
<br />
<br />
{| class="wikitable" align="center" style="text-align:center" border="1" cellpadding="5" cellspacing="0" width=850px<br />
|+ '''FITS filenames'''<br />
|- bgcolor="ffdead"<br />
! Frequency || Survey 1 maps || Survey 2 maps<br />
|-<br />
| '''30GHz''' || {{PLASingleFile|fileType=map|name=LFI_SkyMap_030_1024_R1.10_survey_1.fits|link=LFI_SkyMap_030_1024_R1.10_survey_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=LFI_SkyMap_030_1024_R1.10_survey_2.fits|link=LFI_SkyMap_030_1024_R1.10_survey_2.fits}}<br />
|-<br />
| '''44GHz''' || {{PLASingleFile|fileType=map|name=LFI_SkyMap_044_1024_R1.10_survey_1.fits|link=LFI_SkyMap_044_1024_R1.10_survey_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=LFI_SkyMap_044_1024_R1.10_survey_2.fits|link=LFI_SkyMap_044_1024_R1.10_survey_2.fits}}<br />
|-<br />
| '''70GHz''' || {{PLASingleFile|fileType=map|name=LFI_SkyMap_070_1024_R1.10_survey_1.fits|link=LFI_SkyMap_070_1024_R1.10_survey_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=LFI_SkyMap_070_1024_R1.10_survey_2.fits|link=LFI_SkyMap_070_1024_R1.10_survey_2.fits}}<br />
|-<br />
| '''70GHz''' || {{PLASingleFile|fileType=map|name=LFI_SkyMap_070_2048_R1.10_survey_1.fits|link=LFI_SkyMap_070_2048_R1.10_survey_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=LFI_SkyMap_070_2048_R1.10_survey_2.fits|link=LFI_SkyMap_070_2048_R1.10_survey_2.fits}}<br />
|-<br />
| '''100GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_100_2048_R1.10_survey_1.fits|link=HFI_SkyMap_100_2048_R1.10_survey_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_100_2048_R1.10_survey_2.fits|link=HFI_SkyMap_100_2048_R1.10_survey_2.fits}}<br />
|-<br />
| '''143GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_143_2048_R1.10_survey_1.fits|link=HFI_SkyMap_143_2048_R1.10_survey_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_143_2048_R1.10_survey_2.fits|link=HFI_SkyMap_143_2048_R1.10_survey_2.fits}}<br />
|-<br />
| '''217GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_217_2048_R1.10_survey_1.fits|link=HFI_SkyMap_217_2048_R1.10_survey_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_217_2048_R1.10_survey_2.fits|link=HFI_SkyMap_217_2048_R1.10_survey_2.fits}}<br />
|-<br />
| '''353GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_353_2048_R1.10_survey_1.fits|link=HFI_SkyMap_353_2048_R1.10_survey_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_353_2048_R1.10_survey_2.fits|link=HFI_SkyMap_353_2048_R1.10_survey_2.fits}}<br />
|-<br />
| '''545GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_545_2048_R1.10_survey_1.fits|link=HFI_SkyMap_545_2048_R1.10_survey_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_545_2048_R1.10_survey_2.fits|link=HFI_SkyMap_545_2048_R1.10_survey_2.fits}}<br />
|-<br />
| '''857GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_857_2048_R1.10_survey_1.fits|link=HFI_SkyMap_857_2048_R1.10_survey_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_857_2048_R1.10_survey_2.fits|link=HFI_SkyMap_857_2048_R1.10_survey_2.fits}}<br />
|- bgcolor="ffdead"<br />
! Frequency || Survey 1 Zodi-corrected maps || Survey 2 Zodi-corrected maps<br />
|-<br />
| '''100GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_100_2048_R1.10_survey_1_ZodiCorrected.fits|link=HFI_SkyMap_100_2048_R1.10_survey_1_ZodiCorrected.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_100_2048_R1.10_survey_2_ZodiCorrected.fits|link=HFI_SkyMap_100_2048_R1.10_survey_2_ZodiCorrected.fits}}<br />
|-<br />
| '''143GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_143_2048_R1.10_survey_1_ZodiCorrected.fits|link=HFI_SkyMap_143_2048_R1.10_survey_1_ZodiCorrected.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_143_2048_R1.10_survey_2_ZodiCorrected.fits|link=HFI_SkyMap_143_2048_R1.10_survey_2_ZodiCorrected.fits}}<br />
|-<br />
| '''217GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_217_2048_R1.10_survey_1_ZodiCorrected.fits|link=HFI_SkyMap_217_2048_R1.10_survey_1_ZodiCorrected.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_217_2048_R1.10_survey_2_ZodiCorrected.fits|link=HFI_SkyMap_217_2048_R1.10_survey_2_ZodiCorrected.fits}}<br />
|-<br />
| '''353GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_353_2048_R1.10_survey_1_ZodiCorrected.fits|link=HFI_SkyMap_353_2048_R1.10_survey_1_ZodiCorrected.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_353_2048_R1.10_survey_2_ZodiCorrected.fits|link=HFI_SkyMap_353_2048_R1.10_survey_2_ZodiCorrected.fits}}<br />
|-<br />
| '''545GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_545_2048_R1.10_survey_1_ZodiCorrected.fits|link=HFI_SkyMap_545_2048_R1.10_survey_1_ZodiCorrected.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_545_2048_R1.10_survey_2_ZodiCorrected.fits|link=HFI_SkyMap_545_2048_R1.10_survey_2_ZodiCorrected.fits}}<br />
|-<br />
| '''857GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_857_2048_R1.10_survey_1_ZodiCorrected.fits|link=HFI_SkyMap_857_2048_R1.10_survey_1_ZodiCorrected.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_857_2048_R1.10_survey_2_ZodiCorrected.fits|link=HFI_SkyMap_857_2048_R1.10_survey_2_ZodiCorrected.fits}}<br />
|- bgcolor="ffdead"<br />
! Frequency || Half-ring 1 maps ||Half-ring 2 maps<br />
|-<br />
| '''30GHz''' || {{PLASingleFile|fileType=map|name=LFI_SkyMap_030_1024_R1.10_nominal_ringhalf_1.fits|link=LFI_SkyMap_030_1024_R1.10_nominal_ringhalf_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=LFI_SkyMap_030_1024_R1.10_nominal_ringhalf_2.fits|link=LFI_SkyMap_030_1024_R1.10_nominal_ringhalf_2.fits}}<br />
|-<br />
| '''44GHz''' || {{PLASingleFile|fileType=map|name=LFI_SkyMap_044_1024_R1.10_nominal_ringhalf_1.fits|link=LFI_SkyMap_044_1024_R1.10_nominal_ringhalf_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=LFI_SkyMap_044_1024_R1.10_nominal_ringhalf_2.fits|link=LFI_SkyMap_044_1024_R1.10_nominal_ringhalf_2.fits}}<br />
|-<br />
| '''70GHz''' || {{PLASingleFile|fileType=map|name=LFI_SkyMap_070_1024_R1.10_nominal_ringhalf_1.fits|link=LFI_SkyMap_070_1024_R1.10_nominal_ringhalf_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=LFI_SkyMap_070_1024_R1.10_nominal_ringhalf_2.fits|link=LFI_SkyMap_070_1024_R1.10_nominal_ringhalf_2.fits}}<br />
|-<br />
| '''70GHz''' || {{PLASingleFile|fileType=map|name=LFI_SkyMap_070_2048_R1.10_nominal_ringhalf_1.fits|link=LFI_SkyMap_070_2048_R1.10_nominal_ringhalf_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=LFI_SkyMap_070_2048_R1.10_nominal_ringhalf_2.fits|link=LFI_SkyMap_070_2048_R1.10_nominal_ringhalf_2.fits}}<br />
|-<br />
| '''100GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_100_2048_R1.10_nominal_ringhalf_1.fits|link=HFI_SkyMap_100_2048_R1.10_nominal_ringhalf_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_100_2048_R1.10_nominal_ringhalf_2.fits|link=HFI_SkyMap_100_2048_R1.10_nominal_ringhalf_2.fits}}<br />
|-<br />
| '''143GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_143_2048_R1.10_nominal_ringhalf_1.fits|link=HFI_SkyMap_143_2048_R1.10_nominal_ringhalf_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_143_2048_R1.10_nominal_ringhalf_2.fits|link=HFI_SkyMap_143_2048_R1.10_nominal_ringhalf_2.fits}}<br />
|-<br />
| '''217GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_217_2048_R1.10_nominal_ringhalf_1.fits|link=HFI_SkyMap_217_2048_R1.10_nominal_ringhalf_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_217_2048_R1.10_nominal_ringhalf_2.fits|link=HFI_SkyMap_217_2048_R1.10_nominal_ringhalf_2.fits}}<br />
|-<br />
| '''353GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_353_2048_R1.10_nominal_ringhalf_1.fits|link=HFI_SkyMap_353_2048_R1.10_nominal_ringhalf_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_353_2048_R1.10_nominal_ringhalf_2.fits|link=HFI_SkyMap_353_2048_R1.10_nominal_ringhalf_2.fits}}<br />
|-<br />
| '''545GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_545_2048_R1.10_nominal_ringhalf_1.fits|link=HFI_SkyMap_545_2048_R1.10_nominal_ringhalf_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_545_2048_R1.10_nominal_ringhalf_2.fits|link=HFI_SkyMap_545_2048_R1.10_nominal_ringhalf_2.fits}}<br />
|-<br />
| '''857GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_857_2048_R1.10_nominal_ringhalf_1.fits|link=HFI_SkyMap_857_2048_R1.10_nominal_ringhalf_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_857_2048_R1.10_nominal_ringhalf_2.fits|link=HFI_SkyMap_857_2048_R1.10_nominal_ringhalf_2.fits}}<br />
|}<br />
<br />
''' FITS file structure '''<br />
<br />
<br />
[[File:FITS_FreqMap.png | 500px | right | thumb | '''FITS file structure''']]<br />
<br />
The FITS files for the sky maps contain a minimal primary header with no data, and a ''BINTABLE'' extension (EXTENSION 1, EXTNAME = ''FREQ-MAP'') containing the data. The structure is shows schematically in the figure at right. <br />
<br />
The ''FREQ-MAP'' extension contains is a 3-column table that contain the signal, hit-count and variance maps, all in Healpix format, in columns 1, 2, and 3, respectively. The number of rows is 50331648 for HFI and LFI 70 GHz at Nside=2048 and 12582912 for LFI maps at Nside=1024 (N.B: Npix = 12 Nside^2). The three columns are ''I_STOKES'' for the intensity (or temperature) signal, ''HIT'' for the hit-count and ''II_COV'' for the variance. The exact order of the columns in the figure is indicative only, and the details can be found in the keywords. <br />
<br />
Keywords indicate the coordinate system (GALACTIC), the Healpix ordering scheme (NESTED), the units (K_cmb or MJy/sr) of each column, and of course the frequency channel (FREQ). The COMMENT fields give a one-line summary of the product, and some other information useful for traceability within the DPCs. The original filename is also given in the ''FILENAME'' keyword as are the datasum and the md5 checksum for the extension. The ''BAD_DATA'' keyword gives the value used by Healpix to indicate pixels for which no signal is present (these will also have a hit-count value of 0). The COMMENT fields give further information including some traceability data for the DPC's. The main parameters are summarised below:<br />
<br />
<br />
{| border="1" cellpadding="3" cellspacing="0" align="center" style="text-align:left" width=800px<br />
|+ '''Sky map file data structure'''<br />
|- bgcolor="ffdead" <br />
!colspan="4" | 1. EXTNAME = 'FREQ-MAP' : Data columns<br />
|- bgcolor="ffdead" <br />
! Column Name || Data Type || Units || Description<br />
|-<br />
|I_STOKES || Real*4 || K_cmb or MJy/sr || The signal map<br />
|-<br />
|HITS || Int*4 || none || The hit-count map<br />
|-<br />
|II_COV || Real*4 || K_cmb<sup>2</sup> or (MJy/sr)<sup>2</sup> || The variance map<br />
|- bgcolor="ffdead" <br />
! Keyword || Data Type || Value || Description<br />
|-<br />
|PIXTYPE || string || HEALPIX ||<br />
|-<br />
|COORDSYS || string || GALACTIC ||Coordinate system <br />
|-<br />
|ORDERING || string || NESTED || Healpix ordering<br />
|-<br />
|NSIDE || Int || 1024 or 2048 || Healpix Nside <br />
|-<br />
|FIRSTPIX || Int*4 || 0 || First pixel number<br />
|-<br />
|LASTPIX || Int*4 || 12582911 or 50331647 || Last pixel number<br />
|-<br />
|FREQ || string || nnn || The frequency channel <br />
|}<br />
<br />
<br />
The same structure applies to all ''SkyMap'' products, independent of whether they are full channel, survey of half-ring. The distinction between the types of maps is present in the FITS filename (and in the traceability comment fields).<br />
<br />
''' References'''<br />
<br />
<References /><br />
<br />
<br />
</div><br />
</div><br />
<br />
<br />
<br />
[[Category:Mission products|002]]</div>Azaccheihttps://wiki.cosmos.esa.int/planck-legacy-archive/index.php?title=File:LFI_070GHz_dx12_U.png&diff=14106File:LFI 070GHz dx12 U.png2018-07-06T13:27:33Z<p>Azacchei: </p>
<hr />
<div></div>Azaccheihttps://wiki.cosmos.esa.int/planck-legacy-archive/index.php?title=File:LFI_070GHz_dx12_Q.png&diff=14105File:LFI 070GHz dx12 Q.png2018-07-06T13:27:19Z<p>Azacchei: </p>
<hr />
<div></div>Azaccheihttps://wiki.cosmos.esa.int/planck-legacy-archive/index.php?title=File:LFI_070GHz_dx12_I.png&diff=14104File:LFI 070GHz dx12 I.png2018-07-06T13:27:05Z<p>Azacchei: </p>
<hr />
<div></div>Azaccheihttps://wiki.cosmos.esa.int/planck-legacy-archive/index.php?title=File:LFI_044GHz_dx12_U.png&diff=14103File:LFI 044GHz dx12 U.png2018-07-06T13:26:49Z<p>Azacchei: </p>
<hr />
<div></div>Azaccheihttps://wiki.cosmos.esa.int/planck-legacy-archive/index.php?title=File:LFI_044GHz_dx12_Q.png&diff=14102File:LFI 044GHz dx12 Q.png2018-07-06T13:26:17Z<p>Azacchei: </p>
<hr />
<div></div>Azaccheihttps://wiki.cosmos.esa.int/planck-legacy-archive/index.php?title=File:LFI_044GHz_dx12_I.png&diff=14101File:LFI 044GHz dx12 I.png2018-07-06T13:26:03Z<p>Azacchei: </p>
<hr />
<div></div>Azaccheihttps://wiki.cosmos.esa.int/planck-legacy-archive/index.php?title=File:LFI_030GHz_dx12_U.png&diff=14100File:LFI 030GHz dx12 U.png2018-07-06T13:25:43Z<p>Azacchei: </p>
<hr />
<div></div>Azaccheihttps://wiki.cosmos.esa.int/planck-legacy-archive/index.php?title=File:LFI_030GHz_dx12_Q.png&diff=14099File:LFI 030GHz dx12 Q.png2018-07-06T13:25:20Z<p>Azacchei: </p>
<hr />
<div></div>Azaccheihttps://wiki.cosmos.esa.int/planck-legacy-archive/index.php?title=File:LFI_030GHz_dx12_I.png&diff=14098File:LFI 030GHz dx12 I.png2018-07-06T13:24:59Z<p>Azacchei: </p>
<hr />
<div></div>Azaccheihttps://wiki.cosmos.esa.int/planck-legacy-archive/index.php?title=Frequency_maps&diff=14097Frequency maps2018-07-06T13:17:20Z<p>Azacchei: /* LFI processing */</p>
<hr />
<div>{{DISPLAYTITLE:Frequency maps in Temperature and Polarization}}<br />
==General description==<br />
<br />
Sky maps give the best estimate of the intensity and polarization (Stokes <i>Q</i> and <i>U</i> components), if available, of the signal from the sky after removal, as far as possible, of known systematic effects (mostly instrumental, but including also the solar and Earth-motion dipoles, Galactic stray light, and the zodiacal light). The Planck Collaboration has made three releases of maps, in 2013, 2015 and 2018. This section describes the 2018 release. For descriptions of the other two releases, please go to 2013, and 2015.<br />
<br />
In the 2013, 2015 and 2018 releases, sky maps are provided for the full Planck mission using all valid detectors in each frequency channel, and also for various subsets obtained by splitting the mission into various time ranges or into subsets of the detectors in a given channel, or by considering only odd or even pointing periods. These products are especially interesting for characterization purposes (see also the [[HFI-Validation | data validation]] section), though some are also useful for the study of source variability. The details of the start and end of the time ranges are given in the table below. <br />
<br />
For this (2018) release, HFI is providing a more limited subset of maps that include the full channel maps, the half-mission and the odd-even ring splits. Also, note that for the 353 GHz band, both full channel and PSBs only maps are provided, and that by default it is the PBS-only maps that are served.<br />
<br />
<br />
{| border="1" cellpadding="3" cellspacing="0" align="center" style="text-align:left" width=800px<br />
|+ '''Ranges for mission and surveys'''<br />
|- bgcolor="ffdead" <br />
! Range || ODs || HFI rings || pointing-IDs || Comment<br />
|-<br />
|Nominal mission || 91 - 563 || 240 - 14723 || 00004200 - 03180200 ||<br />
|-<br />
|Full mission || 91 - 974 || 240 - 27005 || 00004200 - 05322620 || For HFI<br />
|-<br />
|Full mission || 91 - 1543 || n/a || 00004200 - 06511160 || For LFI<br />
|-<br />
|Survey 1 || 91 - 270 || 240 - 5720 || 00004200 - 01059820 ||<br />
|-<br />
|Survey 2 || 270 - 456 || 5721 - 11194 || 01059830 - 02114520 ||<br />
|-<br />
|Survey 3 || 456 - 636 || 11195 - 16691 || 02114530 - 03193660 ||<br />
|-<br />
|Survey 4 || 636 - 807 || 16692 - 21720 || 03193670 - 04243900 ||<br />
|-<br />
|Survey 5 || 807 - 974 || 21721 - 26050 || 05267180 - 05322590 || End of mission for HFI<br />
|-<br />
|Survey 5 || 807 - 993 || n/a || 05267180 - 06344800 || End of survey for LFI<br />
|-<br />
|Survey 6 || 993 - 1177 || n/a || 06344810 - 06398120 || LFI only <br />
|-<br />
|Survey 7 || 1177 - 1358 || n/a || 06398130 - 06456410 || LFI only <br />
|-<br />
|Survey 8 || 1358 - 1543 || n/a || 06456420 - 06511160 || LFI only <br />
|-<br />
|HFI mission-half-1 || 91 - 531 || 240 - 13471 || 00004200 - 03155580 ||<br />
|-<br />
|HFI mission-half-2 || 531 - 974 || 13472 - 27005 || 03155590 - 05322590 ||<br />
|-<br />
|LFI Year 1 || 91 - 456 || n/a || 00004200 - 02114520 ||<br />
|-<br />
|LFI Year 2 || 456 - 807 || n/a || 02114530 - 04243900 ||<br />
|-<br />
|LFI Year 3 || 807 - 1177 || n/a || 05267180 - 06398120 ||<br />
|-<br />
|LFI Year 4 || 1177 - 1543 || n/a || 06398130 - 06511160 ||<br />
|-<br />
|}<br />
<br />
To help in further processing, there are also masks of the Galactic plane and of point sources, each provided for several different depths. <br />
<br />
All sky maps are in HEALPix format, with <i>N</i><sub>side</sub>=1024 (for LFI 30, 44, and 70GHz) and 2048 (for LFI 70GHz and HFI), in Galactic coordinates, and with nested ordering. <br />
<br />
'''WARNING''': The HEALPix convention for polarization is <b>not</b> the same as the IAU convention ([[#Polarization convention used in the Planck project|Section 8 on this page]]).<br />
<br />
The signal is given in units of K<sub>CMB</sub> for 30 to 353 GHz, and of MJy.sr<sup>-1</sup> (for a constant &nu;<i>I</i><sub>&nu;</sub> energy distribution) for 545 and 857 GHz. For each frequency channel, the intensity and polarization maps are packaged into a "BINTABLE" extension of a FITS file together with a hit-counts map (or "hits map", for short, giving the number of observation samples that are accumulated in a pixel, all detectors combined) and with the variance and covariance maps. Additional information is given in the FITS file header. The structure of the FITS file is given in the [[#FITS_file_structure | FITS file structure]] section below.<br />
<br />
==Production process==<br />
<br />
Sky maps are produced by appropriately combining the data from all working detectors in a frequency channel over some period of the mission. They give the best estimate of the signal from the sky (unpolarized) after removal, as far as possible, of known systematic effects and of the dipole signals induced by the motion of the solar system in the CMB and of the Planck satellite in the solar system. In particular, they include the zodiacal light emission ("zodi" for short) and also the scattering from the far sidelobes of the beams (FSL). More on this below.<br />
<br />
=== HFI processing ===<br />
<br />
The mapmaking and calibration process is described in detail in the [[Map-making_LFI | mapmaking]] section and in the {{PlanckPapers|planck2016-XLVI}} paper, where detailed references can be found. In brief, the timelines are cleaned and calibrated and converted into HealPix rings (HPRs), then ''SRoll'' is applied to destripe them in polarised space (removal of very low frequency noise by minimising differences at ring crossing points), to remove knows systematic effects (including the flux calibration), and to project them onto a HealPix map.<br />
<br />
The processing yields maps of the signal, hit counts and auto- and cross-variance maps for the 6 full channel and for a pseudo-channel built from the 353 PSBs only. For each channel HFI provides <br />
* a map for the full mission<br />
* two maps for each half-mission<br />
* two maps for built from odd or even rings only<br />
<br />
for a total of 35 maps. <br />
<br />
==== PR3 HFI products ====<br />
<br />
===== Healpix Pixel Rings (HPRs) =====<br />
''SRoll'' main products are the HFI frequency maps. Nevertheless, we also make available the Healpix Pixel Rings (HPRs) of those maps, ie. the data before projection. See [[Healpix_Rings_HFI| description of those files]].<br />
<br />
===== Frequency maps =====<br />
<br />
The 35 HFI frequency maps of the PR3 Legacy Release are the followings:<br />
<br />
{| border="1" cellpadding="3" cellspacing="0" align="center" style="text-align:left" width=800px<br />
|+ '''PR3 HFI frequency maps'''<br />
|- bgcolor="ffdead"<br />
!<br />
!100 GHz<br />
!143 GHz<br />
!217 GHz<br />
!353 GHz<br />
!353_PSB GHz<br />
!545 GHz<br />
!857 GHz<br />
|-<br />
| Full mission<br />
| I, Q, U<br />
| I, Q, U<br />
| I, Q, U<br />
| I, Q, U<br />
| I, Q, U<br />
| I<br />
| I<br />
|-<br />
| Half mission 1<br />
| I, Q, U<br />
| I, Q, U<br />
| I, Q, U<br />
| I, Q, U<br />
| I, Q, U<br />
| I<br />
| I<br />
|-<br />
| Half mission 2<br />
| I, Q, U<br />
| I, Q, U<br />
| I, Q, U<br />
| I, Q, U<br />
| I, Q, U<br />
| I<br />
| I<br />
|-<br />
| Odd rings<br />
| I, Q, U<br />
| I, Q, U<br />
| I, Q, U<br />
| I, Q, U<br />
| I, Q, U<br />
| I<br />
| I<br />
|-<br />
| Even rings<br />
| I, Q, U<br />
| I, Q, U<br />
| I, Q, U<br />
| I, Q, U<br />
| I, Q, U<br />
| I<br />
| I<br />
|}<br />
<br />
See [[Frequency_maps|description of those files]]. These maps are available on the [[https://www.cosmos.esa.int/web/planck/pla| Planck Legacy Archive]].<br />
<br />
<br />
=== LFI processing ===<br />
LFI maps were constructed with the MADAM mapmaking code, version 3.7.4. The code is based on a generalized destriping technique, where the correlated noise component is modelled as a sequence of constant offsets, called "baselines". A noise filter was used to constrain the baseline solution, allowing the use of 0.25-s and 1-s baselines for the 30 and 44GHz, and 70 GHz channels, respectively. See section 6 of {{PlanckPapers|planck2016-l02}}.<br />
<br />
<br />
Radiometers were combined according to the horn-uniform weighting scheme to minimize systematics. The flagged samples were excluded from the analysis by setting their weights to <i>C</i><sub>w</sub><sup>-1</sup> = 0. The Galaxy region was masked out in the destriping phase, to reduce errors arising from strong signal gradients. The polarization component was included in the analysis. <br />
<br />
; Dipole and Far Side Lobe correction: Input timelines are cleaned by the 4&pi;-convolved dipole and Galactic stray light, obtained as a convolution of the 4&pi; in-band far sidelobes and Galactic simulations, as explained in {{PlanckPapers|planck2016-l02}}. <br />
<br />
Scaling of the maps due to beam effects is taken into account in the LFI's beam functions (as provided in [[The_RIMO|the RIMO]]) which should be used for analysis of diffuse components.<br />
<br />
; Bandpass leakage correction :LFI high-resolution maps have been reseleased corrected for bandpass leakage or uncorrected. Further details about the procedure used to generate the bandpass correction maps can be found in section 7 of {{PlanckPapers|planck2016-l02}}.<br />
<br />
; Map zero-level : The 30, 44 and 70 GHz, maps are corrected for a zero-level monopole by applying an offset correction (see the LFI Calibration paper, {{PlanckPapers|planck2014-a06}}). Note that the offset applied is indicated in the header as a comment keyword.<br />
<br />
A detailed description of the mapmaking procedure is given in {{PlanckPapers|planck2013-p02}}, {{PlanckPapers|planck2014-a03}}, {{PlanckPapers|planck2014-a07}} and in the [[Map-making LFI#Map-making|Mapmaking]] section here, in {{PlanckPapers|planck2016-l02}} only a summary is reported.<br />
<br />
==Types of map ==<br />
<br />
=== Full-mission, full-channel maps (7 HFI, 4 LFI)===<br />
<br />
Full channel maps are built using all the valid detectors of a frequency channel and cover either the full or the nominal mission. For HFI, the 143-8 and 545-3 bolometers are rejected entirely, since they are seriously affected by RTS noise. HFI provides the Q and U components for the 100, 143, 217 and 353 GHz channels only. LFI provides the <i>I</i>, <i>Q</i>, and <i>U</i> maps for all the channels. Note that the HFI <i>Q</i> and <i>U</i> maps are corrected for bandpass leakage, but the LFI <i>Q</i> and <i>U</i> maps are not. The <i>I</i>, <i>Q</i>, and <i>U</i> maps are displayed in the figures below. The colour range here is set using a histogram equalization scheme (from HEALPix) that is useful for these non-Gaussian data fields. For visualization purposes, the <i>Q</i> and <i>U</i> maps shown here have been smoothed with a 1&deg; Gaussian kernel, otherwise they look like noise to the naked eye. The 70 GHz full map is also available at <i>N</i><sub>side</sub>=2048.<br />
<br />
The high dynamic range colour scheme of the Planck maps is described [https://wiki.cosmos.esa.int/planck-legacy-archive/index.php/Planck_high_dynamic_range_colour_palette here].<br />
<br />
<center><br />
<gallery style="padding:0 0 0 0;" perrow=3 widths=260px heights=160px> <br />
File: SkyMap30e.png| '''Full mission <i>I</i>, 30 GHz.'''<br />
File: SkyMap44e.png| '''Full mission <i>I</i>, 44 GHz.'''<br />
File: SkyMap70e.png| '''Full mission <i>I</i>, 70 GHz.'''<br />
File: SkyMap100e.png| '''Full mission <i>I</i>, 100 GHz.'''<br />
File: SkyMap143e.png| '''Full mission <i>I</i>, 143 GHz.'''<br />
File: SkyMap217e.png| '''Full mission <i>I</i>, 217 GHz.'''<br />
File: SkyMap353e.png| '''Full mission <i>I</i>, 353 GHz.'''<br />
File: SkyMap545e.png| '''Full mission <i>I</i>, 545 GHz.'''<br />
File: SkyMap857e.png| '''Full mission <i>I</i>, 857 GHz.'''<br />
</gallery><br />
</center><br />
<br><br />
<center><br />
<gallery style="padding:0 0 0 0;" perrow=3 widths=260px heights=160px> <br />
File: LFI_SkyMap_030_1024_R2.01_full_Qb_sm1deg.png| '''Full mission <i>Q</i>, 30 GHz.'''<br />
File: LFI_SkyMap_044_1024_R2.01_full_Qb_sm1deg.png | '''Full mission <i>Q</i>, 44 GHz.'''<br />
File: LFI_SkyMap_070_1024_R2.01_full_Qb_sm1deg.png | '''Full mission <i>Q</i>, 70 GHz.'''<br />
File: HFI_Skymap_100_full_bplcorrected_sm1deg_Qb.png | '''Full mission <i>Q</i>, 100 GHz.'''<br />
File: HFI_Skymap_143_full_bplcorrected_sm1deg_Qb.png | '''Full mission <i>Q</i>, 143 GHz.'''<br />
File: HFI_Skymap_217_full_bplcorrected_sm1deg_Qb.png | '''Full mission <i>Q</i>, 217 GHz.'''<br />
File: HFI_Skymap_353_full_bplcorrected_sm1deg_Qb.png | '''Full mission <i>Q</i>, 353 GHz.'''<br />
</gallery><br />
</center><br />
<br><br />
<center><br />
<gallery style="padding:0 0 0 0;" perrow=3 widths=260px heights=160px> <br />
File: LFI_SkyMap_030_1024_R2.01_full_Ub_sm1deg.png| '''Full mission <i>U</i>, 30 GHz.'''<br />
File: LFI_SkyMap_044_1024_R2.01_full_Ub_sm1deg.png | '''Full mission <i>U</i>, 44 GHz.'''<br />
File: LFI_SkyMap_070_1024_R2.01_full_Ub_sm1deg.png | '''Full mission <i>U</i>, 70 GHz.'''<br />
File: HFI_Skymap_100_full_bplcorrected_sm1deg_Ub.png | '''Full mission <i>U</i>, 100 GHz.'''<br />
File: HFI_Skymap_143_full_bplcorrected_sm1deg_Ub.png | '''Full mission <i>U</i>, 143 GHz.'''<br />
File: HFI_Skymap_217_full_bplcorrected_sm1deg_Ub.png | '''Full mission <i>U</i>, 217 GHz.'''<br />
File: HFI_Skymap_353_full_bplcorrected_sm1deg_Ub.png | '''Full mission <i>U</i>, 353 GHz.'''<br />
</gallery><br />
<br />
</center><br />
<br />
=== Full mission light maps, full channel maps (7 HFI, 7 LFI)===<br />
<br />
These maps are based on the Full mission maps but contain fewer columns, IQU from 30 to 353 GHz, and I only at 545 and 857 GHz. These maps have been produced to reduce the transfer time of the most downloaded frequency full mission maps.<br />
<br />
=== Single-survey, full-channel maps (35 LFI)===<br />
<br />
Single-survey maps are built using all valid detectors of a frequency channel; they separately cover the different sky surveys. The surveys are defined as the times over which the satellite spin axis rotates by 180&deg;, which, due to the position of the detectors in the focal plane does not cover the full sky, but a fraction between about 80% and 90%, depending on detector position. During adjacent surveys the sky is scanned in opposite directions (more precisely it is the ecliptic equator that is scanned in opposite directions). While these are useful to investigate variable sources, they are also used to study the systematics of the time-response of the detectors as they scan bright sources, like the Galactic Plane, in different directions during different survey. Note that the HFI and LFI missions cover five and eight surveys, respectively, and in the case of HFI the last survey in incomplete.<br />
The 70 GHz survey maps are available also at <i>N</i><sub>side</sub>=2048. Note that LFI provides a special survey-map combination used in the low-&#8467; analysis; this maps, available at the three LFI frequencies, 30, 44, and 70 GHz, was built using the combination of Surveys 1, 3, 5, 6, 7, and 8.<br />
<br />
=== Year maps, full-channel maps (16 LFI)===<br />
<br />
These maps are built using the data of Surveys 1+2, Surveys 3+4, and so forth. They are used to study long-term systematic effects. The 70 GHz years maps are available also at <i>N</i><sub>side</sub>=2048.<br />
<br />
===Half-mission maps, full-channel maps (14 HFI, 12 LFI)===<br />
<br />
For HFI, the half mission is defined after eliminating those rings that are discarded for all bolometers, many of which occurred during the 5th survey when the "End-of-Life" tests were performed. The remaining rings are divided in half to define the two halves of the mission. This exercise is done for the full mission only.<br />
<br />
For LFI, instead of the half-mission maps, the following year combinations have been created: Year 1+2, Year 1+3, Year 2+4, Year 3+4,<br />
<br />
===Full mission, single-detector maps (22 LFI)===<br />
<br />
For LFI, all the 22 Radiometers maps are available, and (obviously) only in Stokes <i>I</i>.<br />
<br />
===Full-mission, detector-set or detector-pairs maps (8 LFI)===<br />
<br />
The objective here is to build independent temperature (<i>I</i>) and polarization (<i>Q</i> and <i>U</i>) maps using the two pairs of polarization-sensitive detectors of each channel where they are available, i.e., for the 44-353 GHz channels. The table below indicates which detectors were used to build each detector set (detset).<br />
<br />
{| border="1" cellpadding="3" cellspacing="0" align="center" style="text-align:left" width=600px<br />
|+ '''Definition of LFI detector pairs'''<br />
|- bgcolor="ffdead" <br />
!Frequency || Horn pair || Comment <br />
|-<br />
|44 GHz || 24 || This map is only in temperature<br />
|-<br />
|44 GHz || 25 and 26 || <br />
|-<br />
|70 GHz || 18 and 23 || Available also at <i>N</i><sub>side</sub>=2048<br />
|-<br />
|70 GHz || 19 and 22 || Available also at <i>N</i><sub>side</sub>=2048<br />
|-<br />
|70 GHz || 20 and 21 || Available also at <i>N</i><sub>side</sub>=2048<br />
|}<br />
<br />
===Half-ring maps (62 LFI)===<br />
<br />
These maps are similar to the ones described above, but are built using only the first or the second halves of each ring (or pointing period). The HFI provides half-ring maps for the full mission only, as well as for the full channel, the detsets, and the single bolometers. The LFI provides half-ring maps for the full mission in each channel (70 GHz also at <i>N</i><sub>side</sub>=2048), for the full-mission radiometers, and for the full-mission horn pairs.<br />
<br />
=== Odd and even rings maps (14 HFI)<br />
<br />
As the name indicates, these are generated by using only the odd or only the even rings.<br />
<br />
=== Caveats and known issues ===<br />
<br />
'''TBC'''<br />
<br />
==== Caveats when using the HFI frequency maps ====<br />
Some imperfections have shown up in the tests of the HFI PR3 maps that were previously hidden by higher-level systematics in the previous PR2 data. These lead to guidelines for the proper use of the HFI PR3 data.<br />
<br />
===== Monopoles =====<br />
Monopoles, which cannot be extracted from Planck data alone, are adjusted at each frequency (as was done in the previous PR2 release). For component separation, this provides maps that can be used directly in combination with other tracers.<br />
This monopole includes a CIB model, a diffuse ISM signal adjusted on the HI tracer, and a zodiacal emission signal adjusted to the proper absolute intensity.<br />
<br />
=====Use of the 353 GHz SWBs ===== <br />
We deliver two data sets: the recommended one not using the 353 GHz SWBs data, and the other one including the 353 GHz SWBs for specific use like, for example, increasing the signal to noise level at high multipoles.<br />
<br />
===== Color correction and component separation=====<br />
Different responses between bolometers to different foregrounds cannot be used with the PR3 release to extract component maps. Single bolometer maps computed by Sroll in a frequency band, are all adjusted by construction to the band average response.<br />
<br />
===== Sub-pixel effect in very bright regions===== <br />
The bandpass corrections have been optimized for high latitude regions which implied to reduce the noise of the CO and dust bandpass templates to avoid the introduction of significant correlated noise. The effect is negligible for dust but not for CO in very bright regions. See [[subpixel_HFI|detailled description]].<br />
<br />
===== Solar dipole residual===== <br />
The ''Planck'' 2015 Solar dipole is removed from the PR3 HFI maps to be consistent with LFI maps and to facilitate comparison with the previous PR2 ones. The best Solar dipole determination from HFI PR3 data shows a small shift in direction of about 1', but a 1.8 &mu;K lower amplitude. Removal of the ''Planck'' 2015 Solar dipole thus leaves a small but non-negligible dipole residual in the HFI PR3 maps. To correct for this, and adjust maps at the best photometric calibration, users of the HFI PR3 maps should:<br />
# put back into the maps the ''Planck'' 2015 Solar dipole (d,l,b)= (3364.5 &plusmn; 2.0 &mu;K, 264.00 &plusmn; 0.03&deg;, 48.24 &plusmn; 0.02&deg;),<br />
# include the [[#Calibration accuracy|absolute calibration frequency bias]], i.e., multiply by 1 minus the calibration bias,<br />
# lastly, remove the [[#HFI 2018 Solar dipole|HFI 2018 Solar dipole]].<br />
<br />
<br />
<br />
==Inputs==<br />
=== HFI inputs ===<br />
<br />
The HFI mapmaking takes as input:<br />
* the cleaned TOIs of the signal from each detector, together with their flags, produced by the [[TOI processing|TOI processing]] pipeline;<br />
* the TOIs of pointing (quaternions), described in [[Detector_pointing|Detector pointing]];<br />
* bolometer-level characterization data, from the DPC's internal IMO (not distributed);<br />
* Planck orbit data, used to compute and remove the Earth's dipole;<br />
* Planck solar dipole information, used to calibrate the CMB channels;<br />
* planet models used to calibrate the Galactic channels.<br />
<br />
=== LFI inputs ===<br />
<br />
The MADAM mapmaker takes as input:<br />
* the calibrated timelines (for details see [[TOI processing LFI|TOI Processing]]);<br />
* the detector pointings (for details see [[Detector_pointing|Detector pointing]]);<br />
* the noise information in the form of 3-parameter (white noise level &sigma;, slope, and knee frequency <i>f</i><sub>knee</sub>) noise model (for details see [[The RIMO|RIMO]]).<br />
<br />
==Related products==<br />
=== Masks ===<br />
This section presents the "general purpose" masks. Other masks specific to certain products are packaged with those products.<br />
<br />
Note that for this release, HFI has not produced any new masks. <br />
<br />
==== Gatactic Centre masks ====<br />
<br />
'''TBW'''<br />
<br />
<br />
====Point source masks [TO BE REMOVED ??]====<br />
<br />
For HFI and LFI two sets of point-source masks are provided. <br />
* Intensity masks, which remove sources detected with S/N > 5. <br />
* Polarisation masks, which remove sources that have polarization detection significance levels of 99.97 % or greater at the position of a source detected in intensity. They were derived from the polarization maps with dust foreground bandpass mismatch leakage corrections applied. The area excised around each source has a radius of 3σ (width) of the beam, i.e., 1.27 FWHM (for LFI the cut around each source has a radius of 32 arcmin at 30GHz, 27 arcmin at 44 GHz, and 13 arcmin at 70 GHz).<br />
<br />
Both sets of masks are found in the files ''HFI_Mask_PointSrc_2048_R2.00.fits'' and ''LFI_Mask_PointSrc_2048_R2.00.fits'', in which the first extension contains the intensity masks, and the second contains the polarization masks.<br />
<br />
====Galactic plane masks [TO BE REMOVED ??]====<br />
<br />
Eight Galactic emission masks are provided, giving 20, 40, 60, 70, 80, 90, 97, and 99% sky coverage, derived from the 353 GHz map after CMB subtraction. These are independent of frequency channel. Three versions are given: not apodized; and apodized by 2&deg; and 5&deg;. The filenames are ''HFI_Mask_GalPlane-apoN_2048_R2.00.fits'', where <i>N</i> = 0, 2, and 5.<br />
<br />
The masks are shown below. The eight "GalPlane" masks are combined (added together) and shown in a single figure for each of the three apodizations. While the result is quite clear for the case of no apodization, it is less so for the apodized case. The "PointSrc" masks are shown separately for the intensity case.<br />
<br />
<center><br />
<gallery perrow=3 widths=260px heights=160px ><br />
File: GalPlaneMask_apo0.png | '''Galactic plane masks, no apodization.'''<br />
File: GalPlaneMask_apo2.png | '''Galactic plane masks, apodized to 2&deg;.'''<br />
File: GalPlaneMask_apo5.png | '''Galactic plane masks, apodized to 5&deg;.'''<br />
File: PointSrcMask_100.png | '''Point source mask, 100 GHz.'''<br />
File: PointSrcMask_143.png | '''Point source mask, 143 GHz.'''<br />
File: PointSrcMask_217.png | '''Point source mask, 217 GHz.'''<br />
File: PointSrcMask_353.png | '''Point source mask, 343 GHz.'''<br />
File: PointSrcMask_545.png | '''Point source mask, 545 GHz.'''<br />
File: PointSrcMask_857.png | '''Point source mask, 857 GHz.'''<br />
</gallery><br />
</center><br />
<br />
== File names ==<br />
The FITS filenames are of the form ''{H|L}FI_SkyMap_fff{-tag}_Nside_R2.nn_{coverage}-{type}.fits'', where "fff" are three digits to indicate the Planck frequency band, "tag" indicates the single detector or the detset (no "tag" indicates full channel), "Nside" is the HEALPix <i>N</i><sub>side</sub> value of the map, "coverage" indicates which part of the mission is covered (full, half mission, survey, year, etc.), and the optional "type" indicates the subset of input data used. The table below lists the products by type, with the appropriate unix wildcards that form the full filename.<br />
<br />
{| class="wikitable" align="center" style="text-align"left" border="1" cellpadding="15" cellspacing="20" width=880px<br />
|+ '''HFI FITS filenames'''<br />
|- bgcolor="ffdead"<br />
! Coverage || Filename <br />
|-<br />
| Full channel, full mission ||HFI_SkyMap_fff{-tag}_2048_R3.??_full.fits<br />
|-<br />
| Full channel, half mission || HFI_SkyMap_fff{-tag}_2048_R3.??_halfmission-{1/2}.fits<br />
|-<br />
| Full channel, full mission, odd/even ring || HFI_SkyMap_fff{-tag}_2048_R3.??_{odd/even}ring.fits <br />
|}<br />
<br />
{| class="wikitable" align="center" style="text-align"left" border="1" cellpadding="15" cellspacing="20" width=1000px<br />
|+ '''LFI FITS filenames'''<br />
|- bgcolor="ffdead"<br />
! Coverage || Filename || Half-ring filename || Comment<br />
|-<br />
| Full channel, full mission ||LFI_SkyMap_???_1024_R2.??_full.fits ||LFI_SkyMap_???_1024_R2.??_full-ringhalf-?.fits || Available also at Nside = 2048<br />
|-<br />
| Full channel, single survey || LFI_SkyMap_???_1024_R2.??_survey-?.fits || n/a || Available also at <i>N</i><sub>side</sub>=2048<br />
|-<br />
| Full channel, survey combination || LFI_SkyMap_???_1024_R2.??_survey-1-3-5-6-7-8.fits || n/a || n/a<br />
|-<br />
| Full channel, single year || LFI_SkyMap_???_1024_R2.??_year-?.fits || n/a || Available also at <i>N</i><sub>side</sub>=2048<br />
|-<br />
| Full channel, year combination || LFI_SkyMap_???_1024_R2.??_year?-?.fits || n/a || n/a<br />
|-<br />
| Horn pair, full mission || LFI_SkyMap_???-??-??_1024_R2.??_full.fits || LFI_SkyMap_???_??-??_1024_R2.??_full-ringhalf-?.fits || Available also at <i>N</i><sub>side</sub>2048<br />
|-<br />
| Single radiometer, full mission || LFI_SkyMap_???-???_1024_R2.??_full.fits || LFI_SkyMap_???-???_1024_R2.??_full-ringhalf-?.fits || n/a<br />
|}<br />
<br />
For the benefit of users who are only looking for the frequency maps with no additional information, we also provide a file combining the nine frequency maps as separate columns in a single extension. The nine columns in this file contain the intensity maps <i>only</i> and no other information (hits maps or variance maps) is provided.<br />
<br />
== FITS file structure ==<br />
<br />
The FITS files for the sky maps contain a minimal primary header with no data, and a ''BINTABLE'' extension (EXTENSION 1, EXTNAME = ''FREQ-MAP'') containing the data. The structure is shown schematically in the figure below. The ''FREQ-MAP'' extension contains a 3- or 10-column table that contain the signal, hit-count, and variance maps, all in HEALPix format. The 3-column case is for intensity only maps, while the 10-column case is for polarization. The number of rows is the number of map pixels, which is <i>N</i><sub>pix</sub> = 12 <i>N</i><sub>side</sub><sup>2</sup> for HEALPix maps, where <i>N</i><sub>side</sub> = 1024 or 2048 for most the maps presented in this section.<br />
<br />
[[File:FITS_FreqMap.png | 550px | center | thumb | '''FITS file structure.''']]<br />
<br />
Note that file sizes are approximately 0.6 GB for <i>I</i>-only maps and 1.9 GB for <i>IQU</i> maps at <i>N</i><sub>side</sub>=2048, but about 0.14 GB for <i>I</i>-only maps and 0.45 GB for <i>IQU</i> maps at <i>N</i><sub>pix</sub>=1024 .<br />
<br />
Keywords indicate the coordinate system ("GALACTIC"), the HEALPix ordering scheme ("NESTED"), the units (K<sub>CMB</sub> or MJy.sr<sup>-1</sup>) of each column, and of course the frequency channel ("FREQ"). Where polarization <i>Q</i> and <i>U</i> maps are provided, the "COSMO" polarization convention (used in HEALPix) is adopted, and it is specified in the "POLCCONV" keyword (see [[Sky_temperature_maps#Polarization_convention_used_in_the_Planck_project|this section]]). The "COMMENT" fields give a one-line summary of the product, and some other information useful for traceability within the DPCs. The original filename is also given in the "FILENAME" keyword. The "BAD_DATA" keyword gives the value used by HEALPix to indicate pixels for which no signal is present (these will also have a hit-count value of 0). The main parameters are summarized in the table below.<br />
<br />
{| border="1" cellpadding="3" cellspacing="0" align="center" style="text-align:left" width=800px<br />
|+ '''Sky map file data structure'''<br />
|- bgcolor="ffdead" <br />
!colspan="4" | 1. EXTNAME = 'FREQ-MAP' : Data columns<br />
|- bgcolor="ffdead" <br />
! Column name || Data type || Units || Description<br />
|-<br />
|I_STOKES || Real*4 || K<sub>CMB</sub> or MJy.sr<sup>-1</sup> || Stokes <i>I</i> map<br />
|-<br />
|Q_STOKES || Real*4 || K<sub>CMB</sub> or MJy.sr<sup>-1</sup> || Stokes <i>Q</i> map (optional)<br />
|-<br />
|U_STOKES || Real*4 || K<sub>CMB</sub> or MJy.sr<sup>-1</sup> || Stokes <i>U</i> map (optional)<br />
|-<br />
|HITS || Int*4 || none || The hit-count map<br />
|-<br />
|II_COV || Real*4 || K<sub>CMB</sub><sup>2</sup> or (MJy.sr<sup>-1</sup>)<sup>2</sup> || <i>II</i> variance map<br />
|-<br />
|IQ_COV || Real*4 || K<sub>CMB</sub><sup>2</sup> or (MJy.sr<sup>-1</sup>)<sup>2</sup> || <i>IQ</i> variance map (optional)<br />
|-<br />
|IU_COV || Real*4 || K<sub>CMB</sub><sup>2</sup> or (MJy.sr<sup>-1</sup>)<sup>2</sup> || <i>IQ</i> variance map (optional)<br />
|-<br />
|QQ_COV || Real*4 || K<sub>CMB</sub><sup>2</sup> or (MJy.sr<sup>-1</sup>)<sup>2</sup> || <i>QQ</i> variance map (optional)<br />
|-<br />
|QU_COV || Real*4 || K<sub>CMB</sub><sup>2</sup> or (MJy.sr<sup>-1</sup>)<sup>2</sup> || <i>QU</i> variance map (optional)<br />
|-<br />
|UU_COV || Real*4 || K<sub>CMB</sub><sup>2</sup> or (MJy.sr<sup>-1</sup>)<sup>2</sup> || <i>UU</i> variance map (optional)<br />
|-<br />
|- bgcolor="ffdead" <br />
! Keyword || Data type || Value || Description<br />
|-<br />
|PIXTYPE || String || HEALPIX ||<br />
|-<br />
|COORDSYS || String || GALACTIC ||Coordinate system <br />
|-<br />
|ORDERING || String || NESTED || Healpix ordering<br />
|-<br />
|POLCCONV || String || COSMO || Polarization convention<br />
|-<br />
|NSIDE || Int || 1024 or 2048 || HEALPix <i>N</i><sub>side</sub> <br />
|-<br />
|FIRSTPIX || Int*4 || 0 || First pixel number<br />
|-<br />
|LASTPIX || Int*4 || 12 <i>N</i><sub>side</sub><sup>2</sup> – 1 || Last pixel number<br />
|-<br />
|FREQ || String || nnn || Frequency channel <br />
|}<br />
<br />
<br />
The same structure applies to all "SkyMap" products, independent of whether they are full channel, survey of half-ring. The distinction between the types of maps is present in the FITS filename (and in the traceability comment fields).<br />
<br />
==Polarization convention used in the Planck project==<br />
<br />
The FITS keyword "POLCCONV" defines the polarization convention of the data within the file.<br />
The Planck collaboration used the COSMO convention for the polarization angle (as usually adopted in space-based and other CMB missions), whereas other subfields of astronomy usually adopt the IAU convention. The basic difference comes down to whether one thinks of the light rays being emitted from the origin (the usual mathematics/physics convention) or converging on the observer from the sky (the usual astronomy convention), and hence the "obvious" choice is different for a physicists and for an astronomer. Given that CMB results are of interest to a wide range of both physicists and astronomers, there is no single choice of convention that everyone would regard as self-evident. Hence one simply has to be aware of the convention being adopted. Because of this the Planck Collaboration has taken pains to point out which convention is being used in publications and in data releases. In the following we describe the difference between these two conventions, and the consequence if it is <i>not</i> taken into account correctly in the analysis.<br />
<br />
[[File:conventions.png|thumb|center|400px|'''Figure 1. Polarization conventions, showing the COSMO convention (left) and IAU convention (right). The vector <math>\hat{z}</math> points in the outward direction in COSMO, and inwards in IAU. The bottom panel refers to the plane tangent to the sphere.''']]<br />
<br />
Changing the orientation convention is equivalent to a transformation &psi;'=&pi;-&psi; of the polarization angle (Figure 1). The consequence of this transformation is the inversion of the Stokes parameter <i>U</i>.<br />
The components of the polarization tensor in the helicity basis <math>\epsilon^{\pm}=(\hat{x}\pm i\hat{y})/\sqrt{2}</math> are<br />
<br />
<math><br />
(Q+iU)(\hat{n}) = \sum _{\ell m}a_{2,lm}{}_{2}Y_{\ell }^{m}(\hat{n}),<br />
\\(Q-iU)(\hat{n}) = \sum _{\ell m}a_{-2,lm}{}_{2}Y_{\ell }^{m}(\hat{n}),<br />
</math><br />
<br />
where <math>{}_{2}Y_{\ell }^{m}(\hat{n})</math> are the spin-weighted spherical harmonic functions.<br />
The <i>E</i> and <i>B</i> modes can be defined as<br />
<br />
<math><br />
E(\hat{n}) = \sum_{\ell m}a_{E,\ell m}Y_{\ell }^{m}(\hat{n}),<br />
\\B(\hat{n}) = \sum_{\ell m}a_{B,\ell m}Y_{\ell }^{m}(\hat{n}),<br />
</math><br />
<br />
where the coefficients <i>a<sub>E,&#8467;m</sub></i> and <i>a<sub>B,&#8467;m</sub></i> are derived from linear combinations of the <i>a<sub>2,&#8467;m</sub></i>, <i>a<sub>-2,&#8467;m</sub></i>, defined implicitly in the first equation (<i>Q</i>&plusmn; i<i>U</i>).<br />
<br />
[[File:test_gradient.jpg|thumb|center|400px|]]<br />
[[File:test_curl.jpg|thumb|center|400px|'''Figure 2. Error on Planck-LFI 70 GHz <i>EE</i> (top) and <i>BB</i> (bottom) power spectra, in the case of an incorrect choice being made for the polarization coordinate system convention (IAU instead of COSMO).''']]<br />
<br />
The effect of the sign inversion of <i>U</i> on the polarization spectra is a non-trivial mixing of <i>E</i> and <i>B</i> modes. <br />
An example of the typical error on <i>EE</i> and <i>BB</i> auto-spectra in the case of the wrong choice for the polarization basis is shown in Figure 2.<br />
<br />
<i>One should be careful</i> to be aware of the polarization convention that is being adopted. If the IAU convention is used in computing the power spectra, then the sign of the <i>U</i> component of the Planck maps must be inverted before computing the <i>E</i> and <i>B</i> modes.<br />
<br />
In astronomical applications it is common to define a pseudo-vector <i>P</i> to show the amplitude and orientation of<br />
polarization on a map. When plotting these line segments to show the orientation of the plane of polarization (or the orthogonal direction, often considered to be the projection of the magnetic field), the results are the same for both the COSMO and IAU conventions. This because the appearance of <i>P</i> is a property of the radiation and hence not affected by the sign of <i>U</i>.<br />
<br />
=== Note on the convention used in the Planck Catalogue of Compact Sources (PCCS) ===<br />
Planck non-cosmology papers sometimes follow the IAU convention for internal analysis, for ease of comparison with other studies (e.g., comparison of Planck-derived thermal dust emission polarization with the optical polarization of starlight). Nevertheless, Planck data products, such as component-separated maps, still use the COSMO convention. The one exception is for the compact source catalogue. Because catalogues of astronomical objects found by Planck need to be compared directly with other source catalogues, the polarized sources described in the Planck Catalogue of Compact Sources follow the IAU convention, and the polarization angles are defined on an interval of [-90&deg;,90&deg;]. To switch to the COSMO convention, the polarization angles listed in the catalogue should be shifted by 90&deg; and multiplied by -1.<br />
<br />
== References ==<br />
<References /><br />
<br />
<br />
<span style="background:green"><br />
<br />
<span style="background:green"><br />
== Previous releases ==<br />
<br />
<div class="toccolours mw-collapsible mw-collapsed" style="background-color: #FFDAB9;width:80%" ><br />
'''2015 Sky temperature and polarization maps'''<br />
<br />
<div class="mw-collapsible-content"><br />
<br />
<br />
'''General description'''<br />
<br />
Sky maps give the best estimate of the intensity and polarization (Stokes Q and U components), if available, of the signal from the sky after removal, as far as possible, of known systematic effects (mostly instrumental, but including also the solar and earth-motion dipole, Galactic strylight and the Zodiacal light). Sky maps are provided for the full Planck mission using all valid detectors in each frequency channel, and also for various subsets by splitting the mission in various time ranges or in subsets of the detectors in a given channel. These products are useful for the study of source variability, but they are especially interesting for characterisation purposes (see also the [[HFI-Validation | data validation]] section). The details of the start and end of the time ranges are given in the table below.<br />
<br />
To help in further processing, there are also masks of the Galactic Plane and of point sources, each provided for several different depths.<br />
<br />
All sky maps are in Healpix format, with Nside of 1024 (LFI 30, 44 and 70) and 2048 (LFI 70 and HFI), in Galactic coordinates, and Nested ordering. <br />
<br />
;WARNING: the Healpix convention for polarization is NOT the same as the IAU convention - see Section 8 in this page.<br />
<br />
The signal is given in units of K<sub>cmb</sub> for 30-353 GHz, and of MJy/sr (for a constant <math>\nu F_\nu</math> energy distribution ) for 545 and 857 GHz. For each frequency channel, the intensity and polarization maps are packaged into a ''BINTABLE'' extension of a FITS file together with a hit-count map (or hit map, for short, giving the number of observation samples that are cumulated in a pixel, all detectors combined) and with the variance and covariance maps. Additional information is given in the FITS file header. The structure of the FITS file is given in the [[#FITS_file_structure | FITS file structure]] section below. <br />
<br />
; R2.00 : this first release (Jan 2015) contains polarisation data for the 353 GHz channel only.<br />
; R2.01 : this second release (May 2015) adds polarisation data to the 100-217 GHz channels.<br />
; R2.02 : a full re-release to correct the Healpix bad pixel value in the maps which was altered during the preparation of the maps and not reset to the correct value (the valid pixels are unchanged). It also fixes some FITS keywords, and includes a full re-release of the Zodi correction maps, with the 100-217 GHz one now including the polarisation correction)<br />
<br />
{| border="1" cellpadding="3" cellspacing="0" align="center" style="text-align:left" width=800px<br />
|+ '''Ranges for mission and surveys'''<br />
|- bgcolor="ffdead" <br />
! Range || ODs || HFI rings || pointing-IDs || Comment<br />
|-<br />
|nominal mission || 91 - 563 || 240 - 14723 || 00004200 - 03180200 ||<br />
|-<br />
|full mission || 91 - 974 || 240 - 27005 || 00004200 - 05322620 || for HFI<br />
|-<br />
|full mission || 91 - 1543 || n/a || 00004200 - 06511160 || for LFI<br />
|-<br />
|Survey 1 || 91 - 270 || 240 - 5720 || 00004200 - 01059820 ||<br />
|-<br />
|Survey 2 || 270 - 456 || 5721 - 11194 || 01059830 - 02114520 ||<br />
|-<br />
|Survey 3 || 456 - 636 || 11195 - 16691 || 02114530 - 03193660 ||<br />
|-<br />
|Survey 4 || 636 - 807 || 16692 - 21720 || 03193670 - 04243900 ||<br />
|-<br />
|Survey 5 || 807 - 974 || 21721 - 27005 || 05267180 - 05322590 || end of mission for HFI<br />
|-<br />
|Survey 5 || 807 - 993 || n/a || 05267180 - 06344800 || end of survey for LFI<br />
|-<br />
|Survey 6 || 993 - 1177 || n/a || 06344810 - 06398120 || LFI only <br />
|-<br />
|Survey 7 || 1177 - 1358 || n/a || 06398130 - 06456410 || LFI only <br />
|-<br />
|Survey 8 || 1358 - 1543 || n/a || 06456420 - 06511160 || LFI only <br />
|-<br />
|Survey 9 || 1543 - 1604 || n/a || 06511170 - 06533320 || LFI only Not in this delivery<br />
|-<br />
|HFI mission-half-1 || 91 - 531 || 240 - 13471 || 00004200 - 03155580 ||<br />
|-<br />
|HFI mission-half-2 || 531 - 974 || 13472 - 27005 || 03155590 - 05322590 ||<br />
|-<br />
|LFI Year 1 || 91 - 456 || n/a || 00004200 - 02114520 ||<br />
|-<br />
|LFI Year 2 || 456 - 807 || n/a || 02114530 - 04243900 ||<br />
|-<br />
|LFI Year 3 || 807 - 1177 || n/a || 05267180 - 06398120 ||<br />
|-<br />
|LFI Year 4 || 1177 - 1543 || n/a || 06398130 - 06511160 ||<br />
|-<br />
|}<br />
<br />
'''Production process'''<br />
<br />
Sky maps are produced by combining appropriately the data of all working detectors in a frequency channel over some period of the mission. They give the best estimate of the signal from the sky (unpolarised) after removal, as far as possible, of known systematic effects and of the dipole signals induced by the motion of the solar system in the CMB and of the Planck satellite in the solar system. In particular, they include the Zodiacal light emission (Zodi for short) and also the scattering from the far-side lobes of the beams (FSL). More on this below.<br />
<br />
''' HFI processing '''<br />
<br />
The mapmaking and calibration process is described in detail in the [[Map-making_LFI | Map-making]] section and in the {{PlanckPapers|planck2014-a09}} paper, where detailed references are found. In brief it consists of:<br />
<br />
; binning the TOI data onto ''rings'' : Healpix rings (HPRs) are used here, each ring containing the combined data of one pointing period. <br />
; flux calibration : at 100-353 GHz, the flux calibration factors are determined by correlating the signal with the orbital dipole, which is determined very accurately from the Planck satellite orbital parameters provided by Flight Dynamics. This provides a single gain factor per bolometer. At 545 and 857 GHz the gain is determined from the observation of Uranus and Neptune (but not Jupiter which is too bright) and comparison to recent models made explicitly for this mission. A single gain is applied to all rings at these frequencies.<br />
; destriping : in order to remove low-frequency noise, an offset per ring is determined by minimizing the differences between HPRs at their crossings, and removed.<br />
; Zodiacal light correction : a Zodiacal light model is used to build HPRs of the the Zodi emission, which is subtracted from the calibrated HPRs.<br />
; projection onto the map : the offset-corrected, flux-calibrated, and Zodi-cleaned HPRs are projected onto Healpix maps, with the data of each bolometer weighted by a factor of 1/NET of that bolometer.<br />
<br />
These steps are followed by some post-processing which is designed to prepare the maps for the component separation work. This post processing consists of: <br />
<br />
; Dust bandpass leakage correction : the Q and U maps are corrected for the intensity-to-polarisation leakage caused by the foregrounds having a non-CMB spectrum, and as a consequence of the non-identical bandpasses on the different detectors (bandpass mismatch, or BPM). This correction is determined using the ''ground'' method as described in Section 7.3 of {{PlanckPapers|planck2014-a09}}. These correction maps can be found in the Planck Legacy Archive as ''HFI_CorrMap_???-dustleak-ground_2048_R2.0?_{coverage}.fits''. The correction is applied by subtracting the correction map from the corresponding input map. This correction is not applied to the nominal mission maps in order to maintain compatibility with the PR1 products. ''In fact this correction was computed and applied only to the products used in component separation'', so they were not applied to the single survey maps and to the half-ring maps, which are considered characterisation products.<br />
; Far Side Lobe calibration correction : the 100-217 maps are multiplied by factors of 1.00087, 1.00046, and 1.00043, respectively, to compensate for the non-removal of the far-side lobes, and similarly the corresponding covariance maps have also been corrected by multiplication by the square of the factor.<br />
; Fill missing pixels : missing pixels are filled in with a value that is the mean of valid pixels within a given radius. A radius of 1 deg is used for the full channel maps, and 1.5 deg is used for the detset maps. This step is not applied to the single survey maps since they have large swaths of the sky that are not covered.<br />
<br />
; Map zero-level : for the 100 to 857 GHz maps, the zero levels are set to their optimal levels for Galactic and CIB studies. A procedure for adjusting them to astrophysical values is given in the HFI Mapmaking and Calibration paper {{PlanckPapers|planck2014-a09}}.<br />
<br />
These maps provide the main mission products. Together with signal maps, hit count, variance, and variance maps are also produced. The hit maps give the (integer) number of valid TOI-level samples that contribute to the signal of each pixel. All valid samples are counted in the same way, i.e., there is no weighting factor applied. The variance maps project the white noise estimate, provided by the NETs, in the sky domain.<br />
<br />
Note that the nominal mission maps have not had the post-processing applied, which makes them more easily comparable to the PR1 products.<br />
<br />
''' LFI processing '''<br />
LFI maps were constructed with the Madam map-making code, version 3.7.4. The code is based on generalized destriping technique, where the correlated noise component is modeled as a sequence of constant offset, called baselines. A noise filter was used to constrain the baseline solution allowing the use of 0.25 s and 1 second baselines for the 30 and 44, 70 GHz respectively.<br />
<br />
Radiometers were combined according to the horn-uniform weighting scheme to minimize systematics. The used weights are listed in [[Map-making LFI#Map-making|Map-making]]. The flagged samples were excluded from the analysis by setting their weights to <math>C_{w}^{-1}</math> = 0. The galaxy region was masked out in the destriping phase, to reduce error arising from strong signal gradients. The polarization component was included in the analysis... <br />
<br />
; Dipole and Far Side Lobe correction : input timelines are cleaned by 4pi convolved dipole and Galactic Straylight obtained as convolution of the 4pi in band far sidelobes and Galactic Simulation as explained in Section 7.4 of {{PlanckPapers|planck2014-a03}}. <br />
<br />
Beam effects on the LFI maps are described in Section 7.1 of {{PlanckPapers|planck2014-a03}}. Scaling of the maps due to beam effects is taken into account in the LFI's beam functions (as provided in the RIMO, give reference) which should be used for analysis of diffuse components. To compute the flux densities of compact sources, correction must be made for beam effects (see Table 8 of {{PlanckPapers|planck2014-a03}})."<br />
<br />
; Bandpass leakage correction : '''as opposed to the HFI, the LFI high resolution maps have not been corrected for bandpass leakage. Only low resolution (nside 256) maps are provided with the bandpass correction'''. The correction maps (LFI_CorrMap_0??-BPassCorr_*.fits) can be found in the Planck Legacy Archive. Further details about the procedure used to generate the bandpass correction maps can be found in Section 11 of {{PlanckPapers|planck2014-a03}}.<br />
<br />
; Map zero-level : for the 30, 44 and 70 GHz, maps are corrected for zero level monopole by applying an offset correction, see LFI Calibration paper {{PlanckPapers|planck2014-a06}}. Note that the offset applied is indicated in the header as a comment keyword.<br />
<br />
A detailed description of the map-making procedure is given in {{PlanckPapers|planck2013-p02}}, {{PlanckPapers|planck2014-a03}}, {{PlanckPapers|planck2014-a07}} and in section [[Map-making LFI#Map-making|Map-making]].<br />
<br />
'''Types of maps '''<br />
<br />
''' Full mission, full channel maps (6 HFI, 4 LFI)'''<br />
<br />
Full channel maps are built using all the valid detectors of a frequency channel and cover the either the full or the nominal mission. For HFI, the 143-8 and 545-3 bolometers are rejected entirely as they are seriously affected by RTS noise. HFI provides the Q and U components for the 100, 143, 217 and 353 GHz channels only. LFI provides the I, Q and U maps for all the channels. Reminder: HFI Q and U maps are corrected for bandpass leakage but LFI Q and U maps are not. The I, Q and U maps are displayed in the figures below. The color range is set using a histogram equalisation scheme (from HEALPIX) that is useful for these non-Gaussian data fields. For visualization purposes, the Q and U maps shown here have been smoothed with a 1 degree Gaussian kernel, otherwise they look like noise to the naked eye.<br />
The 70 GHz full map is available also at <math>N_{side}</math> 2048.<br />
<br />
<center><br />
<gallery style="padding:0 0 0 0;" perrow=3 widths=260px heights=160px> <br />
File: SkyMap30e.png| '''Full mission I, 30 GHz'''<br />
File: SkyMap44e.png | '''Full mission I, 44 GHz'''<br />
File: SkyMap70e.png | '''Full mission I, 70 GHz'''<br />
File: SkyMap100e.png | '''Full mission I, 100 GHz'''<br />
File: SkyMap143e.png | '''Full mission I, 143 GHz'''<br />
File: SkyMap217e.png | '''Full mission I, 217 GHz'''<br />
File: SkyMap353e.png | '''Full mission I, 353 GHz'''<br />
File: SkyMap545e.png | '''Full mission I, 545 GHz'''<br />
File: SkyMap857e.png | '''Full mission I, 857 GHz'''<br />
</gallery><br />
</center><br />
<br><br />
<center><br />
<gallery style="padding:0 0 0 0;" perrow=3 widths=260px heights=160px> <br />
File: LFI_SkyMap_030_1024_R2.01_full_Qb_sm1deg.png| '''Full mission Q, 30 GHz'''<br />
File: LFI_SkyMap_044_1024_R2.01_full_Qb_sm1deg.png | '''Full mission Q, 44 GHz'''<br />
File: LFI_SkyMap_070_1024_R2.01_full_Qb_sm1deg.png | '''Full mission Q, 70 GHz'''<br />
File: HFI_Skymap_100_full_bplcorrected_sm1deg_Qb.png | '''Full mission Q, 100 GHz'''<br />
File: HFI_Skymap_143_full_bplcorrected_sm1deg_Qb.png | '''Full mission Q, 143 GHz'''<br />
File: HFI_Skymap_217_full_bplcorrected_sm1deg_Qb.png | '''Full mission Q, 217 GHz'''<br />
File: HFI_Skymap_353_full_bplcorrected_sm1deg_Qb.png | '''Full mission Q, 353 GHz'''<br />
</gallery><br />
</center><br />
<br><br />
<center><br />
<gallery style="padding:0 0 0 0;" perrow=3 widths=260px heights=160px> <br />
File: LFI_SkyMap_030_1024_R2.01_full_Ub_sm1deg.png| '''Full mission U, 30 GHz'''<br />
File: LFI_SkyMap_044_1024_R2.01_full_Ub_sm1deg.png | '''Full mission U, 44 GHz'''<br />
File: LFI_SkyMap_070_1024_R2.01_full_Ub_sm1deg.png | '''Full mission U, 70 GHz'''<br />
File: HFI_Skymap_100_full_bplcorrected_sm1deg_Ub.png | '''Full mission U, 100 GHz'''<br />
File: HFI_Skymap_143_full_bplcorrected_sm1deg_Ub.png | '''Full mission U, 143 GHz'''<br />
File: HFI_Skymap_217_full_bplcorrected_sm1deg_Ub.png | '''Full mission U, 217 GHz'''<br />
File: HFI_Skymap_353_full_bplcorrected_sm1deg_Ub.png | '''Full mission U, 353 GHz'''<br />
</gallery><br />
<br />
</center><br />
<br />
''' Full mission light maps, full channel maps (6 HFI, 7 LFI) '''<br />
<br />
These maps are based on the Full mission maps but contain fewer columns, IQU from 30 to 353 GHz, and I only at 545 and 857 GHz. These maps have been produced to reduce the transfer time of the most downloaded frequency full mission maps.<br />
<br />
''' Nominal mission, full channel maps (6 HFI) '''<br />
<br />
These maps are similar to the ones above, but cover the nominal mission only. They are meant primarily to be compared to the PR1 products in order to see the level of improvements in the processing. Because of this, they are produced in Temperature only, and have not had the post-processing applied.<br />
<br />
''' Single survey, full channel maps (30 HFI, 35 LFI)'''<br />
<br />
Single survey maps are built using all valid detectors of a frequency channel; they cover separately the different sky surveys. The surveys are defined as the times over which the satellite spin axis rotates but 180 degrees, which, due to the position of the detectors in the focal plane does not cover the full sky, but a fraction between ~80 and 90% depending on detector position. During adjacent surveys the sky is scanned in opposite directions. More precisely it is the ecliptic equator that is scanned in opposite directions. While these are useful to investigate variable sources, they are also used to study the systematics of the time-response of the detectors as they scan bright sources, like the Galactic Plane, in different directions during different survey. Note that the HFI and LFI missions cover 5 and 8 surveys, respectively, and in case of HFI the last survey in incomplete.<br />
The 70 GHz surveys maps are available also at <math>N_{side}</math> 2048.<br />
Note LFI provide a special surveys maps combination used in the low l analysis. This maps, available at the three LFI frequency 30, 44 and 70 GHz, was built using the combination of survey 1, 3, 5, 6, 7 and 8. <br />
<br />
''' Year maps, full channel maps (12 HFI, 16 LFI)'''<br />
<br />
These maps are built using the data of surveys 1+2, surveys 3+4, and so forth. They are used to study long-term systematic effects.<br />
The 70 GHz years maps are available also at <math>N_{side}</math> 2048.<br />
<br />
'''Half-mission maps, full channel maps (12 HFI, 12 LFI)'''<br />
<br />
For HFI, the half mission is defined after eliminating those rings discarded for all bolometers. There are 347 such rings, may of which are during the 5th survey when the ''End-of-Life'' tests were performed. The remaining 26419 rings are divided in half (up to the odd ring) to define the two halves of the mission. This exercise is done for the full mission only.<br />
<br />
For LFI instead of the half-mission the following year combination has been created: Year 1+2, Year 1+3, Year 2+4, Year 3+4, <br />
<br />
'''Full mission, single detector maps (18 HFI, 22 LFI)'''<br />
<br />
IN case of HFI these maps are built only for the SWBs (non polarized) and contain only temperature data, of course. They are not built for the polarisation sensitive detectors because they are not fixed on the sky as the polarisation component depends on the position angle at the time of observation. Instead, we provide maps built by ''quads'' of polarisation-sensitive detectors (see next section), which have different polarisation angles and that can be used to built I, Q, and U maps<br />
<br />
{| border="1" cellpadding="3" cellspacing="0" align="center" style="text-align:left" width=600px<br />
|+ '''HFI Temperature sensitive bolometers'''<br />
|- bgcolor="ffdead" <br />
!Frequency || Detector names<br />
|-<br />
|143 GHz || 143-5, 6, 7<br />
|-<br />
|217 GHz || 217-1, 2, 3, 4<br />
|-<br />
|353 GHz || 353-1, 2, 7, 8<br />
|-<br />
|545 GHz || 545-1, 2, 4<br />
|-<br />
|857 GHz || 857-1, 2 , 3, 4<br />
|}<br />
<br />
The 143-8 and 353-3 bolometer data are affected by strong RTS (random telegraphic signal) noise. They have not been used in the data processing, and are not delivered. For a figure showing the focal plane layout, see [[Detector_pointing#Introduction_and_Summary | this Introduction]] of the Detector Pointing chapter.<br />
<br />
In case of LFI, all the 22 Radiometers maps are available, those, obviously, are only in temperature.<br />
<br />
'''Full mission, detector set or detector pairs maps (8 HFI, 8 LFI)'''<br />
<br />
The objective here is to build independent temperature (I) and polarisation (Q and U) maps with the two pairs of polarisation sensitive detectors of each channel where they are available, i.e. in the 44-353 GHz channels. The table below indicates which detectors were used to built each detector set (detset).<br />
<br />
<br />
{| border="1" cellpadding="3" cellspacing="0" align="center" style="text-align:left" width=600px<br />
|+ '''Definition of HFI Detector Sets'''<br />
|- bgcolor="ffdead" <br />
!Frequency || DetSet1 || DetSet2 <br />
|-<br />
|100 GHz || 100-1a/b & 100-4a/b || 100-2a/b & 100-3a/b<br />
|-<br />
|143 GHz || 143-1a/b 1 & 43-3a/b || 143-2a/b & 143-4a/b<br />
|-<br />
|217 GHz || 217-5a/b & 217-7a/b || 217-6a/b & 217-8a/b<br />
|-<br />
|353 GHz || 353-3a/b & 353-5a/b || 353-4a/b & 353-6a/b<br />
|}<br />
<br />
{| border="1" cellpadding="3" cellspacing="0" align="center" style="text-align:left" width=600px<br />
|+ '''Definition of LFI Detector Pairs'''<br />
|- bgcolor="ffdead" <br />
!Frequency || Horn Pair || Comment <br />
|-<br />
|44 GHz || 24 || This maps is only in temperature<br />
|-<br />
|44 GHz || 25 & 26 || <br />
|-<br />
|70 GHz || 18 & 23 || Available also at <math>N_{side}</math> = 2048<br />
|-<br />
|70 GHz || 19 & 22 || Available also at <math>N_{side}</math> = 2048<br />
|-<br />
|70 GHz || 20 & 21 || Available also at <math>N_{side}</math> = 2048<br />
|}<br />
<br />
<br />
'''Half-ring maps (64 HFI, 62 LFI)'''<br />
<br />
These maps are similar to the ones above, but are built using only the first or the second half of each ring (or pointing period). The HFI provides half-ring maps for the full mission only, and for the full channel, the detsets, and the single bolometers. The LFI provides half-rings maps for the channel full mission (70 GHz also at <math>N_{side}</math> 2048), for the radiometer full mission and the horn pairs full mission.<br />
<!----<br />
'''Masks'''<br />
<br />
Masks are provided of the Galactic Plane and of the point sources. For the Galactic Plane, eight masks are given covering different fractions of the sky, and for the points sources two masks are given, at the 5 and 10 sigma level, for each Planck HFI and LFI frequency channel. These are generic masks, specific masks applicable to other products are delivered with the products themselves.<br />
---><br />
<br />
''' The Zodiacal light correction maps '''<br />
<br />
The Zodiacal light signal depends on the location of the observer relative to the Zodiacal light bands, and thus it is not a fixed pattern on the sky but depends on the period of observation. The maps presented here are the difference between the uncorrected (and not delivered) and the corrected maps. <br />
<br />
Note that while the Zodiacal light model that is subtracted at ring level (see [[Map-making#Zodiacal_light_correction | here]]) is not polarised, the corrections are not null and Q and U. This is suspected to come from some combination of leakage due to bandpass differences and beam mismatch, and maybe other effects. These leakages are typically of order a few %, at max, of the maximum zodi intensity at I for each channel. They range from ~150 nK at 100 GHz to ~5 uK at 353 GHz.<br />
<br />
''' Caveats and known issues '''<br />
<br />
; HFI polarization 100-217 GHz : at low multipoles, despite the progress that has been made to control the systematic effects present in the maps, polarization data between 100-217 GHz are still contaminated by systematic residuals. Figure 10 of {{PlanckPapers|planck2014-a09}} shows the EE power spectra from the half-difference maps at 100, 143, and 217 GHz and compared to the noise power spectrum from FFP8 simulations. he half-ring differences are compatible with noise while, at multipoles typically lower than 50, detector-set and half-mission differences are dominated by excess power which is larger than the EE CMB signal. The Planck Collaboration has used the range ell>30 to carry out component separation ({{PlanckPapers|planck2014-a11}}), as data at ell<30 is not considered usable for cosmological analyses. The origin of the excess power will be explored in a forthcoming publication.<br />
<br />
<br />
'''Inputs'''<br />
''' HFI inputs '''<br />
<br />
The HFI mapmaking takes as input:<br />
* the cleaned TOIs of signal of each detector, together with their flags, produced by the [[TOI processing|TOI processing]] pipeline;<br />
* the TOIs of pointing (quaternions), described in [[Detector_pointing|Detector pointing]];<br />
* bolometer-level characterization data, from the DPC's internal IMO (not distributed);<br />
* Planck orbit data, used to compute and remove the Earth's dipole;<br />
* Planck solar dipole information, used to calibrate the CMB channels;<br />
* Planet models used to calibrate the Galactic channels.<br />
<br />
''' LFI inputs '''<br />
<br />
The Madam mapmaker takes as input:<br />
<br />
* the calibrated timelines (for details see [[TOI processing LFI|TOI Processing]]);<br />
* the detector pointings (for details see [[Detector_pointing|Detector pointing]]);<br />
* the noise information in the form of 3-parameter (white noise level, &sigma;, slope, and knee frequency, <i>f</i><sub>knee</sub>) noise model (for details see [[The RIMO|RIMO]])<br />
<br />
'''Related products'''<br />
''' Masks '''<br />
<br />
This section presents the masks of the point sources and of the Galactic plane. These are ''general purpose'' masks. Other masks specific to certain products are packaged with the products.<br />
<br />
'''Point source masks'''<br />
<br />
For HFI and LFI two sets of masks are provided: <br />
* Intensity masks, which removes sources detected with SNR > 5. <br />
* Polarisation masks, which remove sources which have polarisation detection significance of 99.97 % or greater at the position of a source detected in intensity. They were derived from the polarisation maps with dust ground bandpass mismatch leakage correction applied. The cut around each source has a radius of 3σ (width) of the beam ~ 1.27 FWHM (for LFI the cut around each source has a radius of 32 arcmin at 30GHz, 27 arcmin at 44 GHz and 13 arcmin at 70 GHz).<br />
<br />
Both sets are found in the files ''HFI_Mask_PointSrc_2048_R2.00.fits'' and ''LFI_Mask_PointSrc_2048_R2.00.fits'' in which the first extension contains the Intensity masks, and the second contains the Polarisation masks.<br />
<br />
'''Galactic plane masks'''<br />
<br />
Eight masks are provided giving 20, 40, 60, 70, 80, 90, 97, and 99% sky coverage derived from the 353 GHz map, after CMB subtraction. They are independent of frequency channel. Three versions of these are given: not apodized, and apodized by 2 and 5 deg. The filenames are ''HFI_Mask_GalPlane-apoN_2048_R2.00.fits'', where N = 0, 2, 5.<br />
<br />
The masks are shows below. The 8 GalPlane masks are combined (added together) and shown in a single figure for each of the three apodization. While the result is quite clear for the case of no apodization, it is less so for the apodized case. The point source masks are shown separately for the Intensity case.<br />
<br />
<center><br />
<gallery perrow=3 widths=260px heights=160px ><br />
File: GalPlaneMask_apo0.png | '''Galactic Plane masks, no apod'''<br />
File: GalPlaneMask_apo2.png | '''Galactic Plane masks, apod 2 deg'''<br />
File: GalPlaneMask_apo5.png | '''Galactic Plane masks, apod 5 deg'''<br />
File: PointSrcMask_100.png | '''PointSource mask 100 GHz'''<br />
File: PointSrcMask_143.png | '''PointSource mask 143 GHz'''<br />
File: PointSrcMask_217.png | '''PointSource mask 217 GHz'''<br />
File: PointSrcMask_353.png | '''PointSource mask 343 GHz'''<br />
File: PointSrcMask_545.png | '''PointSource mask 545 GHz'''<br />
File: PointSrcMask_857.png | '''PointSource mask 857 GHz'''<br />
</gallery><br />
</center><br />
<br />
''' File names '''<br />
The FITS filenames are of the form ''{H|L}FI_SkyMap_fff{-tag}_Nside_R2.nn_{coverage}-{type}.fits'', where ''fff'' are three digits to indicate the Planck frequency band, ''tag'' indicates the single detector or the detset, ''Nside'' is the Healpix Nside of the map, ''coverage'' indicates which part of the mission is covered (full, half mission, survey, year, ...) , and the optional ''type'' indicates the subset of input data used. The table below lists the products by type, with the appropriate unix wildcards that form the full filename.<br />
<br />
{| class="wikitable" align="center" style="text-align"left" border="1" cellpadding="15" cellspacing="20" width=880px<br />
|+ '''HFI FITS filenames'''<br />
|- bgcolor="ffdead"<br />
! Coverage || filename || half-ring filename <br />
|-<br />
| Full chan, full mission ||HFI_SkyMap_???_2048_R2.??_full.fits ||HFI_SkyMap_???_2048_R2.??_full-ringhalf-?.fits<br />
|-<br />
| Full channel, nominal mission ||HFI_SkyMap_???_2048_R2.??_nominal.fits || n/a<br />
|-<br />
| Full channel, single survey || HFI_SkyMap_???_2048_R2.??_survey-?.fits || n/a<br />
|-<br />
| Full channel, single year || HFI_SkyMap_???_2048_R2.??_year-?.fits || n/a<br />
|-<br />
| Full channel, half mission || HFI_SkyMap_???_2048_R2.??_halfmission*-?.fits || n/a<br />
|-<br />
| Det-set, full mission || HFI_SkyMap_???-ds?_2048_R2.??_full.fits || HFI_SkyMap_???-ds?_2048_R2.??_full-ringhalf-?.fits<br />
|-<br />
|Single SWB, full mission || HFI_SkyMap_???-?_2048_R2.??_full.fits || HFI_SkyMap_???-?_2048_R2.??_full-ringhalf-?.fits<br />
|}<br />
<br />
{| class="wikitable" align="center" style="text-align"left" border="1" cellpadding="15" cellspacing="20" width=1000px<br />
|+ '''LFI FITS filenames'''<br />
|- bgcolor="ffdead"<br />
! Coverage || filename || half-ring filename || Comment<br />
|-<br />
| Full channel, full mission ||LFI_SkyMap_???_1024_R2.??_full.fits ||LFI_SkyMap_???_1024_R2.??_full-ringhalf-?.fits || Available also at Nside = 2048<br />
|-<br />
| Full channel, single survey || LFI_SkyMap_???_1024_R2.??_survey-?.fits || n/a || Available also at Nside = 2048<br />
|-<br />
| Full channel, survey combination || LFI_SkyMap_???_1024_R2.??_survey-1-3-5-6-7-8.fits || n/a || n/a<br />
|-<br />
| Full channel, single year || LFI_SkyMap_???_1024_R2.??_year-?.fits || n/a || Available also at Nside = 2048<br />
|-<br />
| Full channel, year combination || LFI_SkyMap_???_1024_R2.??_year?-?.fits || n/a || n/a<br />
|-<br />
| Horn pair, full mission || LFI_SkyMap_???-??-??_1024_R2.??_full.fits || LFI_SkyMap_???_??-??_1024_R2.??_full-ringhalf-?.fits || Available also at Nside = 2048<br />
|-<br />
| Single radiometer, full mission || LFI_SkyMap_???-???_1024_R2.??_full.fits || LFI_SkyMap_???-???_1024_R2.??_full-ringhalf-?.fits || n/a<br />
|}<br />
<br />
<br />
<br />
For the benefit of users who are only looking for the frequency maps with no additional information, we also provide a file combining the 9 frequency maps as separate columns in a single extension. The 9 columns in this file contain the intensity maps ONLY and no other information (hit maps and variance maps) is provided.<br />
<br />
<!---<br />
{| class="wikitable" align="center" style="text-align:center" border="1" cellpadding="3" cellspacing="0" width=500px<br />
|+ '''FITS filenames'''<br />
|- bgcolor="ffdead"<br />
! Frequency || Full channel maps<br />
|-<br />
| '''30GHz''' || {{PLASingleFile|fileType=map|name=LFI_SkyMap_030_1024_R1.10_nominal.fits|link=LFI_SkyMap_030_1024_R1.10_nominal.fits}}<br />
|-<br />
| '''44GHz''' || {{PLASingleFile|fileType=map|name=LFI_SkyMap_044_1024_R1.10_nominal.fits|link=LFI_SkyMap_044_1024_R1.10_nominal.fits}}<br />
|-<br />
| '''70GHz''' || {{PLASingleFile|fileType=map|name=LFI_SkyMap_070_1024_R1.10_nominal.fits|link=LFI_SkyMap_070_1024_R1.10_nominal.fits}}<br />
|-<br />
| '''70GHz''' || {{PLASingleFile|fileType=map|name=LFI_SkyMap_070_2048_R1.10_nominal.fits|link=LFI_SkyMap_070_2048_R1.10_nominal.fits}}<br />
|-<br />
| '''100GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_100_2048_R1.10_nominal.fits|link=HFI_SkyMap_100_2048_R1.10_nominal.fits}}<br />
|-<br />
| '''143GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_143_2048_R1.10_nominal.fits|link=HFI_SkyMap_143_2048_R1.10_nominal.fits}}<br />
|-<br />
| '''217GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_217_2048_R1.10_nominal.fits|link=HFI_SkyMap_217_2048_R1.10_nominal.fits}}<br />
|-<br />
| '''353GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_353_2048_R1.10_nominal.fits|link=HFI_SkyMap_353_2048_R1.10_nominal.fits}}<br />
|-<br />
| '''545GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_545_2048_R1.10_nominal.fits|link=HFI_SkyMap_545_2048_R1.10_nominal.fits}}<br />
|-<br />
| '''857GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_857_2048_R1.10_nominal.fits|link=HFI_SkyMap_857_2048_R1.10_nominal.fits}}<br />
|- bgcolor="ffdead"<br />
! Frequency || Full channel, Zodi-corrected maps<br />
|-<br />
| '''100GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_100_2048_R1.10_nominal_ZodiCorrected.fits|link=HFI_SkyMap_100_2048_R1.10_nominal_ZodiCorrected.fits}} <br />
|-<br />
| '''143GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_143_2048_R1.10_nominal_ZodiCorrected.fits|link=HFI_SkyMap_143_2048_R1.10_nominal_ZodiCorrected.fits}}<br />
|-<br />
| '''217GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_217_2048_R1.10_nominal_ZodiCorrected.fits|link=HFI_SkyMap_217_2048_R1.10_nominal_ZodiCorrected.fits}}<br />
|-<br />
| '''353GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_353_2048_R1.10_nominal_ZodiCorrected.fits|link=HFI_SkyMap_353_2048_R1.10_nominal_ZodiCorrected.fits}}<br />
|-<br />
| '''545GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_545_2048_R1.10_nominal_ZodiCorrected.fits|link=HFI_SkyMap_545_2048_R1.10_nominal_ZodiCorrected.fits}}<br />
|-<br />
| '''857GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_857_2048_R1.10_nominal_ZodiCorrected.fits|link=HFI_SkyMap_857_2048_R1.10_nominal_ZodiCorrected.fits}}<br />
|- bgcolor="ffdead"<br />
! Frequency || Combined frequency maps<br />
|-<br />
| '''All''' || {{PLASingleFile|fileType=file|name=COM_MapSet_I-allFreqs_R1.10_nominal.fits|link=COM_MapSet_I-allFreqs_R1.10_nominal.fits}} <br />
|}<br />
<br />
<br />
{| class="wikitable" align="center" style="text-align:center" border="1" cellpadding="3" cellspacing="0" width=850px<br />
|+ '''FITS filenames'''<br />
|- bgcolor="ffdead"<br />
! Frequency || Survey 1 maps || Survey 2 maps<br />
|-<br />
| '''30GHz''' || {{PLASingleFile|fileType=map|name=LFI_SkyMap_030_1024_R1.10_survey_1.fits|link=LFI_SkyMap_030_1024_R1.10_survey_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=LFI_SkyMap_030_1024_R1.10_survey_2.fits|link=LFI_SkyMap_030_1024_R1.10_survey_2.fits}}<br />
|-<br />
| '''44GHz''' || {{PLASingleFile|fileType=map|name=LFI_SkyMap_044_1024_R1.10_survey_1.fits|link=LFI_SkyMap_044_1024_R1.10_survey_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=LFI_SkyMap_044_1024_R1.10_survey_2.fits|link=LFI_SkyMap_044_1024_R1.10_survey_2.fits}}<br />
|-<br />
| '''70GHz''' || {{PLASingleFile|fileType=map|name=LFI_SkyMap_070_1024_R1.10_survey_1.fits|link=LFI_SkyMap_070_1024_R1.10_survey_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=LFI_SkyMap_070_1024_R1.10_survey_2.fits|link=LFI_SkyMap_070_1024_R1.10_survey_2.fits}}<br />
|-<br />
| '''70GHz''' || {{PLASingleFile|fileType=map|name=LFI_SkyMap_070_2048_R1.10_survey_1.fits|link=LFI_SkyMap_070_2048_R1.10_survey_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=LFI_SkyMap_070_2048_R1.10_survey_2.fits|link=LFI_SkyMap_070_2048_R1.10_survey_2.fits}}<br />
|-<br />
| '''100GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_100_2048_R1.10_survey_1.fits|link=HFI_SkyMap_100_2048_R1.10_survey_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_100_2048_R1.10_survey_2.fits|link=HFI_SkyMap_100_2048_R1.10_survey_2.fits}}<br />
|-<br />
| '''143GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_143_2048_R1.10_survey_1.fits|link=HFI_SkyMap_143_2048_R1.10_survey_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_143_2048_R1.10_survey_2.fits|link=HFI_SkyMap_143_2048_R1.10_survey_2.fits}}<br />
|-<br />
| '''217GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_217_2048_R1.10_survey_1.fits|link=HFI_SkyMap_217_2048_R1.10_survey_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_217_2048_R1.10_survey_2.fits|link=HFI_SkyMap_217_2048_R1.10_survey_2.fits}}<br />
|-<br />
| '''353GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_353_2048_R1.10_survey_1.fits|link=HFI_SkyMap_353_2048_R1.10_survey_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_353_2048_R1.10_survey_2.fits|link=HFI_SkyMap_353_2048_R1.10_survey_2.fits}}<br />
|-<br />
| '''545GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_545_2048_R1.10_survey_1.fits|link=HFI_SkyMap_545_2048_R1.10_survey_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_545_2048_R1.10_survey_2.fits|link=HFI_SkyMap_545_2048_R1.10_survey_2.fits}}<br />
|-<br />
| '''857GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_857_2048_R1.10_survey_1.fits|link=HFI_SkyMap_857_2048_R1.10_survey_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_857_2048_R1.10_survey_2.fits|link=HFI_SkyMap_857_2048_R1.10_survey_2.fits}}<br />
|- bgcolor="ffdead"<br />
! Frequency || Survey 1 Zodi-corrected maps || Survey 2 Zodi-corrected maps<br />
|-<br />
| '''100GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_100_2048_R1.10_survey_1_ZodiCorrected.fits|link=HFI_SkyMap_100_2048_R1.10_survey_1_ZodiCorrected.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_100_2048_R1.10_survey_2_ZodiCorrected.fits|link=HFI_SkyMap_100_2048_R1.10_survey_2_ZodiCorrected.fits}}<br />
|-<br />
| '''143GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_143_2048_R1.10_survey_1_ZodiCorrected.fits|link=HFI_SkyMap_143_2048_R1.10_survey_1_ZodiCorrected.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_143_2048_R1.10_survey_2_ZodiCorrected.fits|link=HFI_SkyMap_143_2048_R1.10_survey_2_ZodiCorrected.fits}}<br />
|-<br />
| '''217GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_217_2048_R1.10_survey_1_ZodiCorrected.fits|link=HFI_SkyMap_217_2048_R1.10_survey_1_ZodiCorrected.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_217_2048_R1.10_survey_2_ZodiCorrected.fits|link=HFI_SkyMap_217_2048_R1.10_survey_2_ZodiCorrected.fits}}<br />
|-<br />
| '''353GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_353_2048_R1.10_survey_1_ZodiCorrected.fits|link=HFI_SkyMap_353_2048_R1.10_survey_1_ZodiCorrected.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_353_2048_R1.10_survey_2_ZodiCorrected.fits|link=HFI_SkyMap_353_2048_R1.10_survey_2_ZodiCorrected.fits}}<br />
|-<br />
| '''545GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_545_2048_R1.10_survey_1_ZodiCorrected.fits|link=HFI_SkyMap_545_2048_R1.10_survey_1_ZodiCorrected.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_545_2048_R1.10_survey_2_ZodiCorrected.fits|link=HFI_SkyMap_545_2048_R1.10_survey_2_ZodiCorrected.fits}}<br />
|-<br />
| '''857GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_857_2048_R1.10_survey_1_ZodiCorrected.fits|link=HFI_SkyMap_857_2048_R1.10_survey_1_ZodiCorrected.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_857_2048_R1.10_survey_2_ZodiCorrected.fits|link=HFI_SkyMap_857_2048_R1.10_survey_2_ZodiCorrected.fits}}<br />
|- bgcolor="ffdead"<br />
! Frequency || Half-ring 1 maps ||Half-ring 2 maps<br />
|-<br />
| '''30GHz''' || {{PLASingleFile|fileType=map|name=LFI_SkyMap_030_1024_R1.10_nominal_ringhalf_1.fits|link=LFI_SkyMap_030_1024_R1.10_nominal_ringhalf_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=LFI_SkyMap_030_1024_R1.10_nominal_ringhalf_2.fits|link=LFI_SkyMap_030_1024_R1.10_nominal_ringhalf_2.fits}}<br />
|-<br />
| '''44GHz''' || {{PLASingleFile|fileType=map|name=LFI_SkyMap_044_1024_R1.10_nominal_ringhalf_1.fits|link=LFI_SkyMap_044_1024_R1.10_nominal_ringhalf_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=LFI_SkyMap_044_1024_R1.10_nominal_ringhalf_2.fits|link=LFI_SkyMap_044_1024_R1.10_nominal_ringhalf_2.fits}}<br />
|-<br />
| '''70GHz''' || {{PLASingleFile|fileType=map|name=LFI_SkyMap_070_1024_R1.10_nominal_ringhalf_1.fits|link=LFI_SkyMap_070_1024_R1.10_nominal_ringhalf_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=LFI_SkyMap_070_1024_R1.10_nominal_ringhalf_2.fits|link=LFI_SkyMap_070_1024_R1.10_nominal_ringhalf_2.fits}}<br />
|-<br />
| '''70GHz''' || {{PLASingleFile|fileType=map|name=LFI_SkyMap_070_2048_R1.10_nominal_ringhalf_1.fits|link=LFI_SkyMap_070_2048_R1.10_nominal_ringhalf_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=LFI_SkyMap_070_2048_R1.10_nominal_ringhalf_2.fits|link=LFI_SkyMap_070_2048_R1.10_nominal_ringhalf_2.fits}}<br />
|-<br />
| '''100GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_100_2048_R1.10_nominal_ringhalf_1.fits|link=HFI_SkyMap_100_2048_R1.10_nominal_ringhalf_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_100_2048_R1.10_nominal_ringhalf_2.fits|link=HFI_SkyMap_100_2048_R1.10_nominal_ringhalf_2.fits}}<br />
|-<br />
| '''143GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_143_2048_R1.10_nominal_ringhalf_1.fits|link=HFI_SkyMap_143_2048_R1.10_nominal_ringhalf_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_143_2048_R1.10_nominal_ringhalf_2.fits|link=HFI_SkyMap_143_2048_R1.10_nominal_ringhalf_2.fits}}<br />
|-<br />
| '''217GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_217_2048_R1.10_nominal_ringhalf_1.fits|link=HFI_SkyMap_217_2048_R1.10_nominal_ringhalf_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_217_2048_R1.10_nominal_ringhalf_2.fits|link=HFI_SkyMap_217_2048_R1.10_nominal_ringhalf_2.fits}}<br />
|-<br />
| '''353GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_353_2048_R1.10_nominal_ringhalf_1.fits|link=HFI_SkyMap_353_2048_R1.10_nominal_ringhalf_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_353_2048_R1.10_nominal_ringhalf_2.fits|link=HFI_SkyMap_353_2048_R1.10_nominal_ringhalf_2.fits}}<br />
|-<br />
| '''545GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_545_2048_R1.10_nominal_ringhalf_1.fits|link=HFI_SkyMap_545_2048_R1.10_nominal_ringhalf_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_545_2048_R1.10_nominal_ringhalf_2.fits|link=HFI_SkyMap_545_2048_R1.10_nominal_ringhalf_2.fits}}<br />
|-<br />
| '''857GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_857_2048_R1.10_nominal_ringhalf_1.fits|link=HFI_SkyMap_857_2048_R1.10_nominal_ringhalf_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_857_2048_R1.10_nominal_ringhalf_2.fits|link=HFI_SkyMap_857_2048_R1.10_nominal_ringhalf_2.fits}}<br />
|}<br />
---><br />
<br />
''' FITS file structure '''<br />
<br />
The FITS files for the sky maps contain a minimal primary header with no data, and a ''BINTABLE'' extension (EXTENSION 1, EXTNAME = ''FREQ-MAP'') containing the data. The structure is shows schematically in the figure below. The ''FREQ-MAP'' extension contains a 3- or a 10-column table that contain the signal, hit-count and variance maps, all in Healpix format. The 3-column case is for intensity only maps, the 10-column case is for polarisation. The number of rows is the number of map pixels, which is Npix = 12 <math>N_{side}</math><sup>2</sup> for Healpix maps, where <math>N_{side}</math> = 1024 or 2048 for most the maps presented in this chapter.<br />
<br />
[[File:FITS_FreqMap.png | 550px | center | thumb | '''FITS file structure''']]<br />
<br />
Note that file sizes are ~0.6 GB for I-only maps and ~1.9 GB for I,Q,U maps at <math>N_{side}</math> 2048 and ~0.14 GB for I-only maps and ~0.45 GB for I,Q,U maps at <math>N_{side}</math> 1024 .<br />
<br />
Keywords indicate the coordinate system (GALACTIC), the Healpix ordering scheme (NESTED), the units (K_cmb or MJy/sr) of each column, and of course the frequency channel (FREQ). Where polarisation Q and U maps are provided, the ''COSMO'' polarisation convention (used in HEALPIX) is adopted, and it is specified in the ''POLCCONV'' keyword (see [[Sky_temperature_maps#Polarization_convention_used_in_the_Planck_project|this section]]. The COMMENT fields give a one-line summary of the product, and some other information useful for traceability within the DPCs. The original filename is also given in the ''FILENAME'' keyword. The ''BAD_DATA'' keyword gives the value used by Healpix to indicate pixels for which no signal is present (these will also have a hit-count value of 0). The main parameters are summarised below:<br />
<br />
<br />
{| border="1" cellpadding="3" cellspacing="0" align="center" style="text-align:left" width=800px<br />
|+ '''Sky map file data structure'''<br />
|- bgcolor="ffdead" <br />
!colspan="4" | 1. EXTNAME = 'FREQ-MAP' : Data columns<br />
|- bgcolor="ffdead" <br />
! Column Name || Data Type || Units || Description<br />
|-<br />
|I_STOKES || Real*4 || K_cmb or MJy/sr || The Stokes I map<br />
|-<br />
|Q_STOKES || Real*4 || K_cmb or MJy/sr || The Stokes Q map (optional)<br />
|-<br />
|U_STOKES || Real*4 || K_cmb or MJy/sr || The Stokes U map (optional)<br />
|-<br />
|HITS || Int*4 || none || The hit-count map<br />
|-<br />
|II_COV || Real*4 || K_cmb<sup>2</sup> or (MJy/sr)<sup>2</sup> || The II variance map<br />
|-<br />
|IQ_COV || Real*4 || K_cmb<sup>2</sup> or (MJy/sr)<sup>2</sup> || The IQ variance map (optional)<br />
|-<br />
|IU_COV || Real*4 || K_cmb<sup>2</sup> or (MJy/sr)<sup>2</sup> || The IQ variance map (optional)<br />
|-<br />
|QQ_COV || Real*4 || K_cmb<sup>2</sup> or (MJy/sr)<sup>2</sup> || The QQ variance map (optional)<br />
|-<br />
|QU_COV || Real*4 || K_cmb<sup>2</sup> or (MJy/sr)<sup>2</sup> || The QU variance map (optional)<br />
|-<br />
|UU_COV || Real*4 || K_cmb<sup>2</sup> or (MJy/sr)<sup>2</sup> || The UU variance map (optional)<br />
|-<br />
|- bgcolor="ffdead" <br />
! Keyword || Data Type || Value || Description<br />
|-<br />
|PIXTYPE || string || HEALPIX ||<br />
|-<br />
|COORDSYS || string || GALACTIC ||Coordinate system <br />
|-<br />
|ORDERING || string || NESTED || Healpix ordering<br />
|-<br />
|POLCCONV || String || COSMO || Polarization convention<br />
|-<br />
|NSIDE || Int || 1024 or 2048 || Healpix <math>N_{side}</math> <br />
|-<br />
|FIRSTPIX || Int*4 || 0 || First pixel number<br />
|-<br />
|LASTPIX || Int*4 || 12 <math>N_{side}</math><sup>2</sup> – 1 || Last pixel number<br />
|-<br />
|FREQ || string || nnn || The frequency channel <br />
|}<br />
<br />
<br />
The same structure applies to all ''SkyMap'' products, independent of whether they are full channel, survey of half-ring. The distinction between the types of maps is present in the FITS filename (and in the traceability comment fields).<br />
<br />
'''Polarization convention used in the Planck project'''<br />
<br />
The Planck collaboration used the COSMO convention for the polarization angle (as usually used in space based CMB missions), whereas other astronomical fields usually use the IAU convention. In the following document we report the difference between these two conventions, and the consequence if it is NOT taken into account correctly in the analysis.<br />
<br />
[[File:conventions.png|thumb|center|400px|'''Figure 1. COSMO convention (left) and IAU convention (right). The versor <math>\hat{z}</math> points outwards the pointing direction in COSMO, and inwards in IAU. The bottom panel refers to the plane tangent to the sphere.''']]<br />
<br />
Changing the orientation convention is equivalent to a transformation <math>\psi'=\pi-\psi</math> of the polarization angle (Figure 1). The consequence of this transformation is the inversion of the Stokes parameter <math>U</math>.<br />
The components of the polarization tensor in the helicity basis <math>\epsilon^{\pm}=1/\sqrt{2}(\hat{x}\pm i\hat{y})</math> are:<br />
<br />
<math><br />
(Q+iU)(\hat{n}) = \sum _{\ell m}a_{2,lm}{}_{2}Y_{\ell }^{m}(\hat{n})<br />
\\(Q-iU)(\hat{n}) = \sum _{\ell m}a_{-2,lm}{}_{2}Y_{\ell }^{m}(\hat{n})<br />
</math><br />
<br />
where <math>{}_{2}Y_{\ell }^{m}(\hat{n})</math> are the spin weighted spherical harmonic functions.<br />
The <math>E</math> and <math>B</math> modes can be defined as:<br />
<math><br />
E(\hat{n}) = \sum_{\ell m}a_{E,\ell m}Y_{\ell }^{m}(\hat{n})<br />
\\B(\hat{n}) = \sum_{\ell m}a_{B,\ell m}Y_{\ell }^{m}(\hat{n})<br />
</math><br />
<br />
where the coefficients <math>a_{E,\ell m}</math> and <math>a_{B,\ell m}</math> are derived from linear combinations of the <math>a_{2,\ell m}</math> , <math>a_{-2,\ell m}</math> defined implicitly in the first equation (<math>Q\pm iU</math>).<br />
<br />
[[File:test_gradient.jpg|thumb|center|400px|]]<br />
[[File:test_curl.jpg|thumb|center|400px|'''Figure 2. Error on Planck-LFI 70 GHz <math>EE</math> (top) and <math>BB</math> (bottom) spectra, in case of wrong choice of the coordinate system convention (IAU instead of COSMO).''']]<br />
<br />
The effect of the sign inversion of <math>U</math> on the polarization spectra is a non trivial mixing of <math>E</math> and <math>B</math> modes. <br />
<br />
An example of the typical error on <math>EE</math> and <math>BB</math> auto-spectra in case of a wrong choice of the polarization basis is shown in Figure 2.<br />
<br />
BE CAREFUL about the polarization convention you are using. If the IAU convention is used in computing the power spectra, the sign of the <math>U</math> component of the Planck maps must be inverted before computing <math>E</math> and <math>B</math> modes.<br />
<br />
''' Note on the convention used by the Planck Catalogue of Compact Sources (PCCS) '''<br />
For continuity with other compact sources catolgues, the Catalogue of Compact Sources provided by Planck follows the IAU convention, and the polarization angles are defined on an interval of [-90&deg;,90&deg;]. To switch to the COSMO convention, the polarization angles listed in the catalogue have to be shifted by 90&deg; and multiplied by -1.<br />
<br />
== References ==<br />
<References /><br />
<br />
</div><br />
</div><br />
<br />
<div class="toccolours mw-collapsible mw-collapsed" style="background-color: #EEE8AA;width:80%" ><br />
'''2013 Sky temperature maps'''<br />
<br />
<div class="mw-collapsible-content"><br />
<br />
'''General description'''<br />
<br />
<br />
Sky maps give the best estimate of the intensity of the signal from the sky after removal, as far as possible, of known systematic effects and of the dipole signals induced by the motion of the solar system in the CMB and of the Planck satellite in the solar system. Sky maps are provided for the nominal Planck mission and also, separately, for the first two single surveys, the third one being covered only for a small part during the nominal mission.The details of the start and end times of each are given in [[HFIpreprocessingstatics | this table]]. As a secondary product, maps with estimates of the Zodiacal light and Far-Side-Lobes contribution removed are also provided. <br />
<br />
For characterization purposes, are also provided maps covering the nominal survey but each one using only half of the available data. These are the ''ringhalf_{1|2}'' maps, which are built using the first and second half of the stable pointing part in each pointing period. These maps are used extensively to investigate the (high frequency) noise properties the maps themselves and of other products described elsewhere (see e.g., the [[HFI-Validation | data validation]] section).<br />
<br />
To help in further processing, there are also masks of the Galactic Plane and of point sources, each provided for several different depths.<br />
<br />
All sky maps are in Healpix format, with Nside of 2048 for HFI and of 1024 for LFI (note that the LFI 70 GHz has been delivered also at Nside of 2048 to be directly comparable with HFI maps), in Galactic coordinates, and Nested ordering. The signal is given in units of K<sub>cmb</sub> for 30-353 GHz, and of MJy/sr (for a constant $\nu F_\nu$ energy distribution ) for 545 and 857 GHz. Each sky map is packaged into a ''BINTABLE'' extension of a FITS file together with a hit-count map (or hit map, for short, giving the number of observation samples that are cumulated in a pixel, all detectors combined) and a variance map (determined from the half-ring maps), and additional information is given in the FITS file header. The structure of the FITS file is given in the [[#Format | FITS file structure]] section below.<br />
<br />
<br />
'''Types of maps '''<br />
<br />
; Full channel maps<br />
: Full channel maps are built using all the valid detectors of a frequency channel and cover the nominal mission. For HFI, the 143-8 and 545-3 bolometers are rejected entirely as they are seriously affected by RTS noise. The maps are displayed in the figures below. The range is the same from 30 - 143 GHz in order to show the CMB at the same level. At higher frequencies the range is increased in order to keep the Galactic Plane from invading the whole sky.<br />
<br />
<center><br />
<gallery style="padding:0 0 0 0;" perrow=3 widths=260px heights=160px> <br />
File: SkyMap30.png| '''Nominal mission, 30 GHz'''<br />
File: SkyMap44.png | '''Nominal mission, 44 GHz'''<br />
File: SkyMap70.png | '''Nominal mission, 70 GHz'''<br />
File: SkyMap100.png | '''Nominal mission, 100 GHz'''<br />
File: SkyMap143.png | '''Nominal mission, 143 GHz'''<br />
File: SkyMap217.png | '''Nominal mission, 217 GHz'''<br />
File: SkyMap353.png | '''Nominal mission, 353 GHz'''<br />
File: SkyMap545.png | '''Nominal mission, 545 GHz'''<br />
File: SkyMap857.png | '''Nominal mission, 857 GHz'''<br />
</gallery><br />
</center><br />
<br />
; Single survey maps <br />
: Single survey maps are built using all valid detectors of a frequency channel; they cover separately the different sky surveys. The surveys are defined as the times over which the satellite spin axis rotates but 180 degrees, which, due to the position of the detectors in the focal plane does not cover the full sky, but a fraction between ~80 and 90% depending on detector position.<br />
<br />
; Detector set or detector pairs maps<br />
: These are maps built from a subset of the detectors in a frequency channel, typically our of two PSB pairs (i.e., four poloarisation-sensitive bolometers with different orientation on the sky), for HFI in order to extract a single temperature map. While none of these maps are part of the first Planck data release, the concept of ''detset'' is used, and thus it is worth mentioning it here. In particular, information by detector set is available at the [[Frequency_maps_angular_power_spectra | sky power spectrum]] level and in the [[The RIMO | RIMO]].<br />
<br />
; Half-ring maps<br />
: Half-ring maps are built using only the first or the second half of the stable pointing period data. There are thus two half-ring maps per frequency channel named ''ringhalf_1'' and ''ringhalf_2'' respectively. These maps are built for characterization purposes in order to perform null tests. In particular, the difference between the two half-ring maps at a given frequency give a good estimate of the high frequency noise in the data (albeit biased low by ~0.5% for the HFI channels due to specifics of the TOI processing).<br />
<br />
; Masks<br />
: Masks are provided of the Galactic Plane and of the point sources. For the Galactic Plane, eight masks are given covering different fractions of the sky, and for the points sources two masks are given, at the 5 and 10 sigma level, for each Planck HFI frequency channel. These are generic masks, specific masks applicable to other products are delivered with the products themselves.<br />
<br />
''' Caveats and known issues'''<br />
<br />
The primary limitation of the HFI maps are<br />
* the absence of correction of the ADC non-linearities,<br />
* the far-side lobe contribution is not accounted for in the processing and in the calibration,<br />
* the dipole removal is based on the non-relativistic approximation which leaves a weak quadrupole component in the map.<br />
And thus the overall calibration accuracy is at the 0.2% level in 100-217 GHz channels<br />
<br />
The LFI 70 GHz maps at Nside=2048 should be considered as additional product, the default are the LFI maps at Nside=1024. No effective beam at Nside=2048 is provided, only at Nside=1024, for this reason the use of the effective beam with maps at Nside 2048 is discouraged.<br />
<br />
''' Map zero-level '''<br />
<br />
For the 100 to 857 GHz maps, the zero levels are set to their optimal levels for Galactic and CIB studies. A procedure for adjusting them to astrophysical values is given in the HFI Calibration paper {{PlanckPapers|planck2013-p03b}}.<br />
<br />
For the 30, 44 and 70 GHz, maps are corrected for zero level monopole by applying an offset correction, see LFI Calibration paper {{PlanckPapers|planck2013-p02b}} section 3.4 "Setting the zero levels in the maps". Note that the offset applied is indicated in the header as a comment keyword.<br />
<br />
''' The Zodiacal light and the Far-Side Lobes '''<br />
<br />
The figures below show the modeled Zodiacal light and Far Side Lobes projected onto the maps; they are simply the difference between the ''main product'' and the ''ZodiCorrected'' maps for the nominal mission. The units are given in the figures. The ''heat'' color table has been used in place of the standard Planck for clarity reasons. <br />
<center><br />
<gallery perrow=3 widths=260px heights=170px><br />
File: ZodiRes100.png | '''zodi/FSL rediduals - 100 GHz'''<br />
File: ZodiRes143.png | '''zodi/FSL rediduals - 143 GHz''' <br />
File: ZodiRes217.png | '''zodi/FSL rediduals - 217 GHz'''<br />
File: ZodiRes353.png | '''zodi/FSL rediduals - 353 GHz'''<br />
File: ZodiRes545.png | '''zodi/FSL rediduals - 545 GHz'''<br />
File: ZodiRes857.png | '''zodi/FSL rediduals - 857 GHz'''<br />
</gallery><br />
</center><br />
The effects of the FSLs are seen most clearly at the highest frequencies, as structures roughly symmetric about the center of the image, which corresponds to the location of the Galactic Centre, which is in turn the source of most of the radiation that is scattered into the FSLs.<br />
<br />
''' Artifacts near caustics of the scanning strategy '''<br />
<br />
The [[Survey scanning and performance|scanning strategy]] is such that regions around the Ecliptic poles are surveyed very deeply and compared to the average, and the transition from the nominal depth to the high depth, as shows on hit-count maps is very rapid, namely a few pixels, for a contrast of ~30. These transitions, or caustics in the maps, occur at different positions on the sky for different detectors, as the positions depend on their location in the focal plane of the instrument. As a result, when data from different detectors are combined to build a full channel map, the the weights of different detectors in the mix changes rapidly across the caustic, and given the remaining errors in the relative calibration of the detectors, a visible effect can be introduced in the maps, especially when the SNR is very high, i.e. at the highest frequencies and near bright regions like the Galactic Plane. Some examples are shown below.<br />
<br />
<center><br />
<gallery perrow=3 heights=260px widths=260pix ><br />
File: causta857.png | '''857 GHz intensity map around (272.5, -27)'''<br />
File: caustb857.png | '''857 GHz intensity map around (264.5, -37.5)'''<br />
File: caustc857.png | '''857 GHz intensity map around (98.5, 43)'''<br />
File: hita857.png | '''857 GHz hit count map around (272.5, -27)'''<br />
File: hitb857.png | '''857 GHz hit count map around (264.5, -37.5)'''<br />
File: hitc857.png | '''857 GHz hit count map around (98.5, 43)'''<br />
</gallery><br />
</center><br />
<br />
'''Production process'''<br />
<br />
<br />
Sky maps are produced by combining appropriately the data of all working detectors in a frequency channel over some period of the mission. They give the best estimate of the signal from the sky (unpolarised) after removal, as far as possible, of known systematic effects and of the dipole signals induced by the motion of the solar system in the CMB and of the Planck satellite in the solar system. In particular, they include the Zodiacal light emission (Zodi for short) and also the scattering from the far-side lobes of the beams (FSL). More on this below.<br />
<br />
''' HFI processing '''<br />
<br />
The inputs to the mapmaking are TOIs of signal that have been cleaned (as far as possible) of instrumental effects and calibrated in absorbed watts. While the processing involved is described in detail in the [[TOI processing|TOI processing]] section, we give a very brief summary here for convenience. That pipeline performs the following operations:<br />
<br />
; demodulation: this is performed around a variable level which is determined from the valid input data (a validity flag from a previous version of the processing is used for this purpose), and the data are converted to engineering units (V) using known conversion coefficients.<br />
; despiking: using the demodulated data converted to V (by the transfer function) the glitches are identified and fitted with templates. A glitch flag is produced that identifies the strongest part of the glitches, and a timeline of glitch tails is produced from the template fits, and subtracted from the demodulated timeline from step 1. Finally, the flagged ranges are replaced with data from an average over the pointing period (TBC)<br />
; dark template removal: the two dark bolometers are demodulated and despiked as above; the resulting timelines are then smoothed and used as an indicator of the overall temperature variations of the bolometer plate. Where the variations are consistent with each other, they are combined and removed from the bolometer signal timelines using appropriate coupling coefficients. The few percent of the data where they are not consistent are flagged on the timelines.<br />
; conversion to absorbed power: the timeline is converted to watts of absorbed power using the bolometer function. This includes a non-linearity correction; removal of the 4K cooler lines: the electromagnetic interference of the 4K cooler with the bolometer readout wires induces some sharp lines in the signal power spectra at frequencies of the 4K cooler's fundamental and its multiples, folded by the signal modulations. Fourier coefficients of the relevant lines are determined on a per-ring basis, and then removed from the data. The quality of the removal depends on the bolometer.<br />
; deconvolution by the time transfer function: this is done to correct for the non-instantaneous time response of the bolometers. The function itself is modeled using 4 parameters which are adjusted primarily on the planet data and also from comparisons of the northward and southward scans of the Galactic Plane. It is then removed using Fourier techniques, which has the side-effect of increasing the noise at high frequencies.<br />
; jump correction: removes some (relatively rare: 0.3 jumps per bolometer per pointing period, on average) jumps in the signal baseline. The jumps are detected characterized on smoothed TOIs, and corrected by adding a constant to part of the signal timeline. The origin of the jumps is not known.<br />
<br />
The results of this processing are a timeline of signal (in absorbed watts) and a ''valid data'' flag timeline for each of the 50 valid bolometers processed; these timelines contain the full sky signal, i.e., including the solar and orbital dipoles, the Zodiacal light, and contributions from the Far-Side lobes. The dipoles are necessary for the flux calibration and are removed at the mapmaking stage. The remaining two bolometers (143-8 and 535-3) show semi-random jumps in the signal level, typically jumping over 2-5 different ''pseudo-baseline'' levels, a behavior known as ''Random Telegraphic Signal'', so that these are commonly called the RTS bolometers. Finally, ring-level statistics of different types (mean, median, rms, kurtosis, etc.) are determined on a per-ring basis for all timelines, and a selection based on these statistics is used to discard anomalous rings, which are recorded in a ring-level flag for each valid bolometer timeline (see the [[TOI_processing#Discarded_rings| Discarded rings]] section). <br />
<br />
Throughout this processing, bright planets (Mars, Jupiter, Saturn, Uranus) and bright asteroids are masked in the timeline in order to avoid ringing effects in the processing. Since they move on the sky, the portion of the sky masked during one survey is observed during one, and no hole is left in the final map. In parallel, the planet data are processed in a similar way, but with different parameters for the despiking step, and without the final jump correction step. These results are processed separately to determine the beam shapes and the focal plane geometry.<br />
<br />
The pointing is determined starting from the AHF produced by MOC, which gives the direction and orientation of the LOS of a fiducial position in the focal plane at frequencies of 8Hz during stable pointing and 4 Hz during maneuvers (TBC for details, reference). This is interpolated to the times of data observation (ref to method), corrected for the wobble and other time-dependent offsets determined from the observed positions of a large number of sources around the sky, and finally converted to the LOS of each detector using the quaternions in the IMO (which are determined from observations of bright planets - see the [[Detector_pointing]] section). <br />
<br />
The mapmaking and calibration process is described in detail in the [[Map-making_LFI | Map-making]] section, where detailed references are found. In brief it consists of:<br />
<br />
; binning the TOI data onto ''rings'' : Healpix rings (HPRs) are used here, each ring containing the combined data of one pointing period. <br />
; flux calibration : at 100-353 GHz, the flux calibration factors are determined for each pointing period (or ring) from the solar-motion dipole, using the WMAP dipole as the reference, and after removal of the dipole signal induced by the motion of the Planck satellite in the solar system. This gain by ring is smoothed with a window of width 50 rings, which reveals an apparent variation of ~1-2% on a scale of 100s to 1000s of rings for the 100-217 GHz channels, and is applied. At 353GHz, where the solar motion dipole is weaker compared to the signal, no gain variation is detected (within the uncertainties), and a single fixed gain is applied to all rings. At 545 and 857 GHz the gain is determined from the observation of Uranus and Neptune (but not Jupiter which is too bright) and comparison to recent models made explicitly for this mission. A single gain is applied to all rings at these frequencies.<br />
; destriping : in order to remove low-frequency noise, an offset per ring is determined by minimizing the differences between HPRs at their crossings, and removed.<br />
; projection onto the map : the offset-corrected and flux-calibrated HPRs are projected onto Healpix maps, with the data of each bolometer weighted by a factor of 1/NET of that bolometer, and accounting for the slight different band transmission profiles of the bolometers in each band. <br />
<br />
These maps provide the main mission products. A second, reduced, set of maps, cleaned of the Zodiacal emission of the FSL leakage is also produced for the nominal mission and the two single surveys, but not for the half-rings (since the contribution would be the same for the two halves of each ring). For this purpose, the the Zodiacal emission and the FSL contamination, which are not fixed on the sky, are modeled separately at HPR-level, and subtracted from the signal HPR before projecting them onto the maps. <br />
<br />
Together with signal maps, hit count and variance maps are also produced. The hit maps give the (integer) number of valid TOI-level samples that contribute to the signal of each pixel. All valid samples are counted in the same way, i.e., there is no weighting factor applied. The variance maps project the white noise estimate, provided by the NETs, in the sky domain.<br />
<br />
''' LFI processing '''<br />
<br />
LFI maps were constructed with the Madam map-making code, version 3.7.4. The code is based on generalized destriping technique, where the correlated noise component is modeled as a sequence of constant offset, called baselines. A noise filter was used to constrain the baseline solution allowing the use of 1 second baselines.<br />
<br />
Radiometers were combined according to the horn-uniform weighting scheme to minimize systematics. The used weights are listed in [[Map-making LFI#Map-making|Map-making]]. The flagged samples were excluded from the analysis by setting their weights to $C_{w}^{-1}$ = 0. The galaxy region was masked out in the destriping phase, to reduce error arising from strong signal gradients. The polarization component was included in the analysis, although only the temperature maps are released. <br />
<br />
A detailed description of the map-making procedure is given in {{PlanckPapers|planck2013-p02}} and in section [[Map-making LFI#Map-making|Map-making]].<br />
<br />
'''Inputs'''<br />
<br />
<br />
''' HFI inputs '''<br />
<br />
* The cleaned TOIs of signal of each detector, together with their flags, produced by the [[TOI processing|TOI processing]] pipeline<br />
* The TOIs of pointing (quaternions), described in [[Detector_pointing]]<br />
* Bolometer-level characterization data, from the DPC's internal IMO (not distributed)<br />
* Planck orbit data used to compute and remove the earth dipole<br />
* WMAP solar dipole information used to calibrate the CMB channels<br />
* Planet models used to calibrate the Galactic channels.<br />
<br />
''' LFI inputs '''<br />
<br />
The Madam map-maker takes as an input:<br />
<br />
* The calibrated timelines (for details see [[TOI processing LFI|TOI Processing]])<br />
* The detector pointings (for details see [[Detector pointing|Detector pointing]])<br />
* The noise information in the form of three-parameter (white noise level ($\sigma$), slope, and knee frequency ($f_\mathrm{knee}$)) noise model (for details see [[The RIMO|RIMO]])<br />
<br />
'''Related products'''<br />
<br />
<br />
''' Masks '''<br />
<br />
Masks are provided of<br />
<br />
; the point sources<br />
: 15 masks are provided, three for the LFI (one mask for each frequency masking at the 4<math>\sigma</math> level) and 12 for the HFI (two masks for each frequency at the 5 and 10<math>\sigma</math> levels. For the HFI the masks can be used as they are, for the LFI they need to be downgraded to Nside=1024 except for the 70 GHz channel at Nside=2048 which does not need to be downgraded.<br />
<br />
; the Galactic Plane<br />
: 8 masks are provided giving 20, 40, 60, 70, 80, 90, 97, and 99% sky coverage in two different files, at Nside=2048. For the HFI they can be used as they are, for the LFI they need to be downgraded at Nside=1024 (note that if using the 70 GHZ at Nside=2048 no downgraded is needed)<br />
<br />
<br />
The masks are binary, in GALACTIC coordinates, and NESTED ordering. The table below give the filenames. <br />
<br />
<br />
{| class="wikitable" align="center" style="text-align:center" border="1" cellpadding="5" cellspacing="0" <br />
|+ '''FITS filenames for masks'''<br />
|-bgcolor="ffdead"<br />
! Frequency || LFI Point Source masks<br />
|-<br />
| '''30GHz''' || {{PLASingleFile|fileType=map|name=LFI_MASK_030-ps_2048_R1.00.fits|link=LFI_MASK_030-ps_2048_R1.00.fits}}<br />
|-<br />
| '''44GHz''' || {{PLASingleFile|fileType=map|name=LFI_MASK_044-ps_2048_R1.00.fits|link=LFI_MASK_044-ps_2048_R1.00.fits}}<br />
|-<br />
| '''70GHz''' || {{PLASingleFile|fileType=map|name=LFI_MASK_070-ps_2048_R1.00.fits|link=LFI_MASK_070-ps_2048_R1.00.fits}}<br />
|- bgcolor="ffdead"<br />
! colspan="2" | HFI Point Source masks<br />
|-<br />
| colspan="2" | {{PLASingleFile|fileType=map|name=HFI_Mask_PointSrc_2048_R1.10.fits|link=HFI_Mask_PointSrc_2048_R1.10.fits}}<br />
|- bgcolor="ffdead"<br />
! colspan="2" | Galactic Plane masks<br />
|-<br />
| colspan="2" | {{PLASingleFile|fileType=map|name=HFI_Mask_GalPlane_2048_R1.10.fits|link=HFI_Mask_GalPlane_2048_R1.10.fits}} <br />
|}<br />
<br />
<br />
The masks are shows below in a single figure. While this is quite clear for the Galactic Plane masks, it is less so for the point source masks, but it does give a clear perspective on how the latter are distributed over the sky.<br />
<br />
<center><br />
<gallery perrow=2 widths=300px heights=185px ><br />
File: HFI_GalPlaneMask.png | '''Galactic Plane masks'''<br />
File: HFI_PointSrcMask.png | '''PointSource masks'''<br />
</gallery><br />
</center><br />
<br />
''' File names '''<br />
<br />
<br />
The FITS filenames are of the form ''{H|L}FI_SkyMap_fff_nnnn_R1.nn_{coverage}_{type}.fits'', where ''fff'' are three digits to indicate the Planck frequency band, and ''nnnn'' is the Healpix Nside of the map, ''coverage'' indicates which part of the mission is covered, and the optional ''type'' indicates the subset of input data used. A full list of products, with links to them in the Archive, is given in the tables below.<br />
<br />
For the benefit of users who are only looking for the frequency maps with no additional information, we also provide a file combining the 9 frequency maps as separate columns in a single extension. The 9 columns in this file contain the intensity maps ONLY and no other information (hit maps and variance maps) is provided.<br />
<br />
{| class="wikitable" align="center" style="text-align:center" border="1" cellpadding="5" cellspacing="0" width=500px<br />
|+ '''FITS filenames'''<br />
|- bgcolor="ffdead"<br />
! Frequency || Full channel maps<br />
|-<br />
| '''30GHz''' || {{PLASingleFile|fileType=map|name=LFI_SkyMap_030_1024_R1.10_nominal.fits|link=LFI_SkyMap_030_1024_R1.10_nominal.fits}}<br />
|-<br />
| '''44GHz''' || {{PLASingleFile|fileType=map|name=LFI_SkyMap_044_1024_R1.10_nominal.fits|link=LFI_SkyMap_044_1024_R1.10_nominal.fits}}<br />
|-<br />
| '''70GHz''' || {{PLASingleFile|fileType=map|name=LFI_SkyMap_070_1024_R1.10_nominal.fits|link=LFI_SkyMap_070_1024_R1.10_nominal.fits}}<br />
|-<br />
| '''70GHz''' || {{PLASingleFile|fileType=map|name=LFI_SkyMap_070_2048_R1.10_nominal.fits|link=LFI_SkyMap_070_2048_R1.10_nominal.fits}}<br />
|-<br />
| '''100GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_100_2048_R1.10_nominal.fits|link=HFI_SkyMap_100_2048_R1.10_nominal.fits}}<br />
|-<br />
| '''143GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_143_2048_R1.10_nominal.fits|link=HFI_SkyMap_143_2048_R1.10_nominal.fits}}<br />
|-<br />
| '''217GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_217_2048_R1.10_nominal.fits|link=HFI_SkyMap_217_2048_R1.10_nominal.fits}}<br />
|-<br />
| '''353GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_353_2048_R1.10_nominal.fits|link=HFI_SkyMap_353_2048_R1.10_nominal.fits}}<br />
|-<br />
| '''545GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_545_2048_R1.10_nominal.fits|link=HFI_SkyMap_545_2048_R1.10_nominal.fits}}<br />
|-<br />
| '''857GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_857_2048_R1.10_nominal.fits|link=HFI_SkyMap_857_2048_R1.10_nominal.fits}}<br />
|- bgcolor="ffdead"<br />
! Frequency || Full channel, Zodi-corrected maps<br />
|-<br />
| '''100GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_100_2048_R1.10_nominal_ZodiCorrected.fits|link=HFI_SkyMap_100_2048_R1.10_nominal_ZodiCorrected.fits}} <br />
|-<br />
| '''143GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_143_2048_R1.10_nominal_ZodiCorrected.fits|link=HFI_SkyMap_143_2048_R1.10_nominal_ZodiCorrected.fits}}<br />
|-<br />
| '''217GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_217_2048_R1.10_nominal_ZodiCorrected.fits|link=HFI_SkyMap_217_2048_R1.10_nominal_ZodiCorrected.fits}}<br />
|-<br />
| '''353GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_353_2048_R1.10_nominal_ZodiCorrected.fits|link=HFI_SkyMap_353_2048_R1.10_nominal_ZodiCorrected.fits}}<br />
|-<br />
| '''545GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_545_2048_R1.10_nominal_ZodiCorrected.fits|link=HFI_SkyMap_545_2048_R1.10_nominal_ZodiCorrected.fits}}<br />
|-<br />
| '''857GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_857_2048_R1.10_nominal_ZodiCorrected.fits|link=HFI_SkyMap_857_2048_R1.10_nominal_ZodiCorrected.fits}}<br />
|- bgcolor="ffdead"<br />
! Frequency || Combined frequency maps<br />
|-<br />
| '''All''' || {{PLASingleFile|fileType=file|name=COM_MapSet_I-allFreqs_R1.10_nominal.fits|link=COM_MapSet_I-allFreqs_R1.10_nominal.fits}} <br />
|}<br />
<br />
<br />
{| class="wikitable" align="center" style="text-align:center" border="1" cellpadding="5" cellspacing="0" width=850px<br />
|+ '''FITS filenames'''<br />
|- bgcolor="ffdead"<br />
! Frequency || Survey 1 maps || Survey 2 maps<br />
|-<br />
| '''30GHz''' || {{PLASingleFile|fileType=map|name=LFI_SkyMap_030_1024_R1.10_survey_1.fits|link=LFI_SkyMap_030_1024_R1.10_survey_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=LFI_SkyMap_030_1024_R1.10_survey_2.fits|link=LFI_SkyMap_030_1024_R1.10_survey_2.fits}}<br />
|-<br />
| '''44GHz''' || {{PLASingleFile|fileType=map|name=LFI_SkyMap_044_1024_R1.10_survey_1.fits|link=LFI_SkyMap_044_1024_R1.10_survey_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=LFI_SkyMap_044_1024_R1.10_survey_2.fits|link=LFI_SkyMap_044_1024_R1.10_survey_2.fits}}<br />
|-<br />
| '''70GHz''' || {{PLASingleFile|fileType=map|name=LFI_SkyMap_070_1024_R1.10_survey_1.fits|link=LFI_SkyMap_070_1024_R1.10_survey_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=LFI_SkyMap_070_1024_R1.10_survey_2.fits|link=LFI_SkyMap_070_1024_R1.10_survey_2.fits}}<br />
|-<br />
| '''70GHz''' || {{PLASingleFile|fileType=map|name=LFI_SkyMap_070_2048_R1.10_survey_1.fits|link=LFI_SkyMap_070_2048_R1.10_survey_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=LFI_SkyMap_070_2048_R1.10_survey_2.fits|link=LFI_SkyMap_070_2048_R1.10_survey_2.fits}}<br />
|-<br />
| '''100GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_100_2048_R1.10_survey_1.fits|link=HFI_SkyMap_100_2048_R1.10_survey_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_100_2048_R1.10_survey_2.fits|link=HFI_SkyMap_100_2048_R1.10_survey_2.fits}}<br />
|-<br />
| '''143GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_143_2048_R1.10_survey_1.fits|link=HFI_SkyMap_143_2048_R1.10_survey_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_143_2048_R1.10_survey_2.fits|link=HFI_SkyMap_143_2048_R1.10_survey_2.fits}}<br />
|-<br />
| '''217GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_217_2048_R1.10_survey_1.fits|link=HFI_SkyMap_217_2048_R1.10_survey_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_217_2048_R1.10_survey_2.fits|link=HFI_SkyMap_217_2048_R1.10_survey_2.fits}}<br />
|-<br />
| '''353GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_353_2048_R1.10_survey_1.fits|link=HFI_SkyMap_353_2048_R1.10_survey_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_353_2048_R1.10_survey_2.fits|link=HFI_SkyMap_353_2048_R1.10_survey_2.fits}}<br />
|-<br />
| '''545GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_545_2048_R1.10_survey_1.fits|link=HFI_SkyMap_545_2048_R1.10_survey_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_545_2048_R1.10_survey_2.fits|link=HFI_SkyMap_545_2048_R1.10_survey_2.fits}}<br />
|-<br />
| '''857GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_857_2048_R1.10_survey_1.fits|link=HFI_SkyMap_857_2048_R1.10_survey_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_857_2048_R1.10_survey_2.fits|link=HFI_SkyMap_857_2048_R1.10_survey_2.fits}}<br />
|- bgcolor="ffdead"<br />
! Frequency || Survey 1 Zodi-corrected maps || Survey 2 Zodi-corrected maps<br />
|-<br />
| '''100GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_100_2048_R1.10_survey_1_ZodiCorrected.fits|link=HFI_SkyMap_100_2048_R1.10_survey_1_ZodiCorrected.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_100_2048_R1.10_survey_2_ZodiCorrected.fits|link=HFI_SkyMap_100_2048_R1.10_survey_2_ZodiCorrected.fits}}<br />
|-<br />
| '''143GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_143_2048_R1.10_survey_1_ZodiCorrected.fits|link=HFI_SkyMap_143_2048_R1.10_survey_1_ZodiCorrected.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_143_2048_R1.10_survey_2_ZodiCorrected.fits|link=HFI_SkyMap_143_2048_R1.10_survey_2_ZodiCorrected.fits}}<br />
|-<br />
| '''217GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_217_2048_R1.10_survey_1_ZodiCorrected.fits|link=HFI_SkyMap_217_2048_R1.10_survey_1_ZodiCorrected.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_217_2048_R1.10_survey_2_ZodiCorrected.fits|link=HFI_SkyMap_217_2048_R1.10_survey_2_ZodiCorrected.fits}}<br />
|-<br />
| '''353GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_353_2048_R1.10_survey_1_ZodiCorrected.fits|link=HFI_SkyMap_353_2048_R1.10_survey_1_ZodiCorrected.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_353_2048_R1.10_survey_2_ZodiCorrected.fits|link=HFI_SkyMap_353_2048_R1.10_survey_2_ZodiCorrected.fits}}<br />
|-<br />
| '''545GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_545_2048_R1.10_survey_1_ZodiCorrected.fits|link=HFI_SkyMap_545_2048_R1.10_survey_1_ZodiCorrected.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_545_2048_R1.10_survey_2_ZodiCorrected.fits|link=HFI_SkyMap_545_2048_R1.10_survey_2_ZodiCorrected.fits}}<br />
|-<br />
| '''857GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_857_2048_R1.10_survey_1_ZodiCorrected.fits|link=HFI_SkyMap_857_2048_R1.10_survey_1_ZodiCorrected.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_857_2048_R1.10_survey_2_ZodiCorrected.fits|link=HFI_SkyMap_857_2048_R1.10_survey_2_ZodiCorrected.fits}}<br />
|- bgcolor="ffdead"<br />
! Frequency || Half-ring 1 maps ||Half-ring 2 maps<br />
|-<br />
| '''30GHz''' || {{PLASingleFile|fileType=map|name=LFI_SkyMap_030_1024_R1.10_nominal_ringhalf_1.fits|link=LFI_SkyMap_030_1024_R1.10_nominal_ringhalf_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=LFI_SkyMap_030_1024_R1.10_nominal_ringhalf_2.fits|link=LFI_SkyMap_030_1024_R1.10_nominal_ringhalf_2.fits}}<br />
|-<br />
| '''44GHz''' || {{PLASingleFile|fileType=map|name=LFI_SkyMap_044_1024_R1.10_nominal_ringhalf_1.fits|link=LFI_SkyMap_044_1024_R1.10_nominal_ringhalf_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=LFI_SkyMap_044_1024_R1.10_nominal_ringhalf_2.fits|link=LFI_SkyMap_044_1024_R1.10_nominal_ringhalf_2.fits}}<br />
|-<br />
| '''70GHz''' || {{PLASingleFile|fileType=map|name=LFI_SkyMap_070_1024_R1.10_nominal_ringhalf_1.fits|link=LFI_SkyMap_070_1024_R1.10_nominal_ringhalf_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=LFI_SkyMap_070_1024_R1.10_nominal_ringhalf_2.fits|link=LFI_SkyMap_070_1024_R1.10_nominal_ringhalf_2.fits}}<br />
|-<br />
| '''70GHz''' || {{PLASingleFile|fileType=map|name=LFI_SkyMap_070_2048_R1.10_nominal_ringhalf_1.fits|link=LFI_SkyMap_070_2048_R1.10_nominal_ringhalf_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=LFI_SkyMap_070_2048_R1.10_nominal_ringhalf_2.fits|link=LFI_SkyMap_070_2048_R1.10_nominal_ringhalf_2.fits}}<br />
|-<br />
| '''100GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_100_2048_R1.10_nominal_ringhalf_1.fits|link=HFI_SkyMap_100_2048_R1.10_nominal_ringhalf_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_100_2048_R1.10_nominal_ringhalf_2.fits|link=HFI_SkyMap_100_2048_R1.10_nominal_ringhalf_2.fits}}<br />
|-<br />
| '''143GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_143_2048_R1.10_nominal_ringhalf_1.fits|link=HFI_SkyMap_143_2048_R1.10_nominal_ringhalf_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_143_2048_R1.10_nominal_ringhalf_2.fits|link=HFI_SkyMap_143_2048_R1.10_nominal_ringhalf_2.fits}}<br />
|-<br />
| '''217GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_217_2048_R1.10_nominal_ringhalf_1.fits|link=HFI_SkyMap_217_2048_R1.10_nominal_ringhalf_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_217_2048_R1.10_nominal_ringhalf_2.fits|link=HFI_SkyMap_217_2048_R1.10_nominal_ringhalf_2.fits}}<br />
|-<br />
| '''353GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_353_2048_R1.10_nominal_ringhalf_1.fits|link=HFI_SkyMap_353_2048_R1.10_nominal_ringhalf_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_353_2048_R1.10_nominal_ringhalf_2.fits|link=HFI_SkyMap_353_2048_R1.10_nominal_ringhalf_2.fits}}<br />
|-<br />
| '''545GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_545_2048_R1.10_nominal_ringhalf_1.fits|link=HFI_SkyMap_545_2048_R1.10_nominal_ringhalf_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_545_2048_R1.10_nominal_ringhalf_2.fits|link=HFI_SkyMap_545_2048_R1.10_nominal_ringhalf_2.fits}}<br />
|-<br />
| '''857GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_857_2048_R1.10_nominal_ringhalf_1.fits|link=HFI_SkyMap_857_2048_R1.10_nominal_ringhalf_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_857_2048_R1.10_nominal_ringhalf_2.fits|link=HFI_SkyMap_857_2048_R1.10_nominal_ringhalf_2.fits}}<br />
|}<br />
<br />
''' FITS file structure '''<br />
<br />
<br />
[[File:FITS_FreqMap.png | 500px | right | thumb | '''FITS file structure''']]<br />
<br />
The FITS files for the sky maps contain a minimal primary header with no data, and a ''BINTABLE'' extension (EXTENSION 1, EXTNAME = ''FREQ-MAP'') containing the data. The structure is shows schematically in the figure at right. <br />
<br />
The ''FREQ-MAP'' extension contains is a 3-column table that contain the signal, hit-count and variance maps, all in Healpix format, in columns 1, 2, and 3, respectively. The number of rows is 50331648 for HFI and LFI 70 GHz at Nside=2048 and 12582912 for LFI maps at Nside=1024 (N.B: Npix = 12 Nside^2). The three columns are ''I_STOKES'' for the intensity (or temperature) signal, ''HIT'' for the hit-count and ''II_COV'' for the variance. The exact order of the columns in the figure is indicative only, and the details can be found in the keywords. <br />
<br />
Keywords indicate the coordinate system (GALACTIC), the Healpix ordering scheme (NESTED), the units (K_cmb or MJy/sr) of each column, and of course the frequency channel (FREQ). The COMMENT fields give a one-line summary of the product, and some other information useful for traceability within the DPCs. The original filename is also given in the ''FILENAME'' keyword as are the datasum and the md5 checksum for the extension. The ''BAD_DATA'' keyword gives the value used by Healpix to indicate pixels for which no signal is present (these will also have a hit-count value of 0). The COMMENT fields give further information including some traceability data for the DPC's. The main parameters are summarised below:<br />
<br />
<br />
{| border="1" cellpadding="3" cellspacing="0" align="center" style="text-align:left" width=800px<br />
|+ '''Sky map file data structure'''<br />
|- bgcolor="ffdead" <br />
!colspan="4" | 1. EXTNAME = 'FREQ-MAP' : Data columns<br />
|- bgcolor="ffdead" <br />
! Column Name || Data Type || Units || Description<br />
|-<br />
|I_STOKES || Real*4 || K_cmb or MJy/sr || The signal map<br />
|-<br />
|HITS || Int*4 || none || The hit-count map<br />
|-<br />
|II_COV || Real*4 || K_cmb<sup>2</sup> or (MJy/sr)<sup>2</sup> || The variance map<br />
|- bgcolor="ffdead" <br />
! Keyword || Data Type || Value || Description<br />
|-<br />
|PIXTYPE || string || HEALPIX ||<br />
|-<br />
|COORDSYS || string || GALACTIC ||Coordinate system <br />
|-<br />
|ORDERING || string || NESTED || Healpix ordering<br />
|-<br />
|NSIDE || Int || 1024 or 2048 || Healpix Nside <br />
|-<br />
|FIRSTPIX || Int*4 || 0 || First pixel number<br />
|-<br />
|LASTPIX || Int*4 || 12582911 or 50331647 || Last pixel number<br />
|-<br />
|FREQ || string || nnn || The frequency channel <br />
|}<br />
<br />
<br />
The same structure applies to all ''SkyMap'' products, independent of whether they are full channel, survey of half-ring. The distinction between the types of maps is present in the FITS filename (and in the traceability comment fields).<br />
<br />
''' References'''<br />
<br />
<References /><br />
<br />
<br />
</div><br />
</div><br />
<br />
<br />
<br />
[[Category:Mission products|002]]</div>Azaccheihttps://wiki.cosmos.esa.int/planck-legacy-archive/index.php?title=Frequency_maps&diff=14096Frequency maps2018-07-06T12:50:24Z<p>Azacchei: /* General description */</p>
<hr />
<div>{{DISPLAYTITLE:Frequency maps in Temperature and Polarization}}<br />
==General description==<br />
<br />
Sky maps give the best estimate of the intensity and polarization (Stokes <i>Q</i> and <i>U</i> components), if available, of the signal from the sky after removal, as far as possible, of known systematic effects (mostly instrumental, but including also the solar and Earth-motion dipoles, Galactic stray light, and the zodiacal light). The Planck Collaboration has made three releases of maps, in 2013, 2015 and 2018. This section describes the 2018 release. For descriptions of the other two releases, please go to 2013, and 2015.<br />
<br />
In the 2013, 2015 and 2018 releases, sky maps are provided for the full Planck mission using all valid detectors in each frequency channel, and also for various subsets obtained by splitting the mission into various time ranges or into subsets of the detectors in a given channel, or by considering only odd or even pointing periods. These products are especially interesting for characterization purposes (see also the [[HFI-Validation | data validation]] section), though some are also useful for the study of source variability. The details of the start and end of the time ranges are given in the table below. <br />
<br />
For this (2018) release, HFI is providing a more limited subset of maps that include the full channel maps, the half-mission and the odd-even ring splits. Also, note that for the 353 GHz band, both full channel and PSBs only maps are provided, and that by default it is the PBS-only maps that are served.<br />
<br />
<br />
{| border="1" cellpadding="3" cellspacing="0" align="center" style="text-align:left" width=800px<br />
|+ '''Ranges for mission and surveys'''<br />
|- bgcolor="ffdead" <br />
! Range || ODs || HFI rings || pointing-IDs || Comment<br />
|-<br />
|Nominal mission || 91 - 563 || 240 - 14723 || 00004200 - 03180200 ||<br />
|-<br />
|Full mission || 91 - 974 || 240 - 27005 || 00004200 - 05322620 || For HFI<br />
|-<br />
|Full mission || 91 - 1543 || n/a || 00004200 - 06511160 || For LFI<br />
|-<br />
|Survey 1 || 91 - 270 || 240 - 5720 || 00004200 - 01059820 ||<br />
|-<br />
|Survey 2 || 270 - 456 || 5721 - 11194 || 01059830 - 02114520 ||<br />
|-<br />
|Survey 3 || 456 - 636 || 11195 - 16691 || 02114530 - 03193660 ||<br />
|-<br />
|Survey 4 || 636 - 807 || 16692 - 21720 || 03193670 - 04243900 ||<br />
|-<br />
|Survey 5 || 807 - 974 || 21721 - 26050 || 05267180 - 05322590 || End of mission for HFI<br />
|-<br />
|Survey 5 || 807 - 993 || n/a || 05267180 - 06344800 || End of survey for LFI<br />
|-<br />
|Survey 6 || 993 - 1177 || n/a || 06344810 - 06398120 || LFI only <br />
|-<br />
|Survey 7 || 1177 - 1358 || n/a || 06398130 - 06456410 || LFI only <br />
|-<br />
|Survey 8 || 1358 - 1543 || n/a || 06456420 - 06511160 || LFI only <br />
|-<br />
|HFI mission-half-1 || 91 - 531 || 240 - 13471 || 00004200 - 03155580 ||<br />
|-<br />
|HFI mission-half-2 || 531 - 974 || 13472 - 27005 || 03155590 - 05322590 ||<br />
|-<br />
|LFI Year 1 || 91 - 456 || n/a || 00004200 - 02114520 ||<br />
|-<br />
|LFI Year 2 || 456 - 807 || n/a || 02114530 - 04243900 ||<br />
|-<br />
|LFI Year 3 || 807 - 1177 || n/a || 05267180 - 06398120 ||<br />
|-<br />
|LFI Year 4 || 1177 - 1543 || n/a || 06398130 - 06511160 ||<br />
|-<br />
|}<br />
<br />
To help in further processing, there are also masks of the Galactic plane and of point sources, each provided for several different depths. <br />
<br />
All sky maps are in HEALPix format, with <i>N</i><sub>side</sub>=1024 (for LFI 30, 44, and 70GHz) and 2048 (for LFI 70GHz and HFI), in Galactic coordinates, and with nested ordering. <br />
<br />
'''WARNING''': The HEALPix convention for polarization is <b>not</b> the same as the IAU convention ([[#Polarization convention used in the Planck project|Section 8 on this page]]).<br />
<br />
The signal is given in units of K<sub>CMB</sub> for 30 to 353 GHz, and of MJy.sr<sup>-1</sup> (for a constant &nu;<i>I</i><sub>&nu;</sub> energy distribution) for 545 and 857 GHz. For each frequency channel, the intensity and polarization maps are packaged into a "BINTABLE" extension of a FITS file together with a hit-counts map (or "hits map", for short, giving the number of observation samples that are accumulated in a pixel, all detectors combined) and with the variance and covariance maps. Additional information is given in the FITS file header. The structure of the FITS file is given in the [[#FITS_file_structure | FITS file structure]] section below.<br />
<br />
==Production process==<br />
<br />
Sky maps are produced by appropriately combining the data from all working detectors in a frequency channel over some period of the mission. They give the best estimate of the signal from the sky (unpolarized) after removal, as far as possible, of known systematic effects and of the dipole signals induced by the motion of the solar system in the CMB and of the Planck satellite in the solar system. In particular, they include the zodiacal light emission ("zodi" for short) and also the scattering from the far sidelobes of the beams (FSL). More on this below.<br />
<br />
=== HFI processing ===<br />
<br />
The mapmaking and calibration process is described in detail in the [[Map-making_LFI | mapmaking]] section and in the {{PlanckPapers|planck2016-XLVI}} paper, where detailed references can be found. In brief, the timelines are cleaned and calibrated and converted into HealPix rings (HPRs), then ''SRoll'' is applied to destripe them in polarised space (removal of very low frequency noise by minimising differences at ring crossing points), to remove knows systematic effects (including the flux calibration), and to project them onto a HealPix map.<br />
<br />
The processing yields maps of the signal, hit counts and auto- and cross-variance maps for the 6 full channel and for a pseudo-channel built from the 353 PSBs only. For each channel HFI provides <br />
* a map for the full mission<br />
* two maps for each half-mission<br />
* two maps for built from odd or even rings only<br />
<br />
for a total of 35 maps. <br />
<br />
==== PR3 HFI products ====<br />
<br />
===== Healpix Pixel Rings (HPRs) =====<br />
''SRoll'' main products are the HFI frequency maps. Nevertheless, we also make available the Healpix Pixel Rings (HPRs) of those maps, ie. the data before projection. See [[Healpix_Rings_HFI| description of those files]].<br />
<br />
===== Frequency maps =====<br />
<br />
The 35 HFI frequency maps of the PR3 Legacy Release are the followings:<br />
<br />
{| border="1" cellpadding="3" cellspacing="0" align="center" style="text-align:left" width=800px<br />
|+ '''PR3 HFI frequency maps'''<br />
|- bgcolor="ffdead"<br />
!<br />
!100 GHz<br />
!143 GHz<br />
!217 GHz<br />
!353 GHz<br />
!353_PSB GHz<br />
!545 GHz<br />
!857 GHz<br />
|-<br />
| Full mission<br />
| I, Q, U<br />
| I, Q, U<br />
| I, Q, U<br />
| I, Q, U<br />
| I, Q, U<br />
| I<br />
| I<br />
|-<br />
| Half mission 1<br />
| I, Q, U<br />
| I, Q, U<br />
| I, Q, U<br />
| I, Q, U<br />
| I, Q, U<br />
| I<br />
| I<br />
|-<br />
| Half mission 2<br />
| I, Q, U<br />
| I, Q, U<br />
| I, Q, U<br />
| I, Q, U<br />
| I, Q, U<br />
| I<br />
| I<br />
|-<br />
| Odd rings<br />
| I, Q, U<br />
| I, Q, U<br />
| I, Q, U<br />
| I, Q, U<br />
| I, Q, U<br />
| I<br />
| I<br />
|-<br />
| Even rings<br />
| I, Q, U<br />
| I, Q, U<br />
| I, Q, U<br />
| I, Q, U<br />
| I, Q, U<br />
| I<br />
| I<br />
|}<br />
<br />
See [[Frequency_maps|description of those files]]. These maps are available on the [[https://www.cosmos.esa.int/web/planck/pla| Planck Legacy Archive]].<br />
<br />
<br />
=== LFI processing ===<br />
LFI maps were constructed with the MADAM mapmaking code, version 3.7.4. The code is based on a generalized destriping technique, where the correlated noise component is modelled as a sequence of constant offsets, called "baselines". A noise filter was used to constrain the baseline solution, allowing the use of 0.25-s and 1-s baselines for the 30 and 44GHz, and 70 GHz channels, respectively.<br />
<br />
Radiometers were combined according to the horn-uniform weighting scheme to minimize systematics. The weights used are listed in [[Map-making LFI#Map-making|Mapmaking]]. The flagged samples were excluded from the analysis by setting their weights to <i>C</i><sub>w</sub><sup>-1</sup> = 0. The Galaxy region was masked out in the destriping phase, to reduce errors arising from strong signal gradients. The polarization component was included in the analysis. <br />
<br />
; Dipole and Far Side Lobe correction: Input timelines are cleaned by the 4&pi;-convolved dipole and Galactic stray light, obtained as a convolution of the 4&pi; in-band far sidelobes and Galactic simulations, as explained in section 7.4 of {{PlanckPapers|planck2014-a03}}. <br />
<br />
Beam effects on the LFI maps are described in section 7.1 of {{PlanckPapers|planck2014-a03}}. Scaling of the maps due to beam effects is taken into account in the LFI's beam functions (as provided in [[The_RIMO|the RIMO]]) which should be used for analysis of diffuse components. To compute the flux densities of compact sources, correction must be made for beam effects (see table 8 of {{PlanckPapers|planck2014-a03}}).<br />
<br />
; Bandpass leakage correction : Unlike for the HFI, the LFI high-resolution maps have not been corrected for bandpass leakage. Only low resolution (<i>N</i><sub>side</sub>=256) maps are provided with the bandpass correction. The correction maps (LFI_CorrMap_0??-BPassCorr_*.fits) can be found in the Planck Legacy Archive. Further details about the procedure used to generate the bandpass correction maps can be found in section 11 of {{PlanckPapers|planck2014-a03}}.<br />
<br />
; Map zero-level : The 30, 44 and 70 GHz, maps are corrected for a zero-level monopole by applying an offset correction (see the LFI Calibration paper, {{PlanckPapers|planck2014-a06}}). Note that the offset applied is indicated in the header as a comment keyword.<br />
<br />
A detailed description of the mapmaking procedure is given in {{PlanckPapers|planck2013-p02}}, {{PlanckPapers|planck2014-a03}}, {{PlanckPapers|planck2014-a07}} and in the [[Map-making LFI#Map-making|Mapmaking]] section here.<br />
<br />
==Types of map ==<br />
<br />
=== Full-mission, full-channel maps (7 HFI, 4 LFI)===<br />
<br />
Full channel maps are built using all the valid detectors of a frequency channel and cover either the full or the nominal mission. For HFI, the 143-8 and 545-3 bolometers are rejected entirely, since they are seriously affected by RTS noise. HFI provides the Q and U components for the 100, 143, 217 and 353 GHz channels only. LFI provides the <i>I</i>, <i>Q</i>, and <i>U</i> maps for all the channels. Note that the HFI <i>Q</i> and <i>U</i> maps are corrected for bandpass leakage, but the LFI <i>Q</i> and <i>U</i> maps are not. The <i>I</i>, <i>Q</i>, and <i>U</i> maps are displayed in the figures below. The colour range here is set using a histogram equalization scheme (from HEALPix) that is useful for these non-Gaussian data fields. For visualization purposes, the <i>Q</i> and <i>U</i> maps shown here have been smoothed with a 1&deg; Gaussian kernel, otherwise they look like noise to the naked eye. The 70 GHz full map is also available at <i>N</i><sub>side</sub>=2048.<br />
<br />
The high dynamic range colour scheme of the Planck maps is described [https://wiki.cosmos.esa.int/planck-legacy-archive/index.php/Planck_high_dynamic_range_colour_palette here].<br />
<br />
<center><br />
<gallery style="padding:0 0 0 0;" perrow=3 widths=260px heights=160px> <br />
File: SkyMap30e.png| '''Full mission <i>I</i>, 30 GHz.'''<br />
File: SkyMap44e.png| '''Full mission <i>I</i>, 44 GHz.'''<br />
File: SkyMap70e.png| '''Full mission <i>I</i>, 70 GHz.'''<br />
File: SkyMap100e.png| '''Full mission <i>I</i>, 100 GHz.'''<br />
File: SkyMap143e.png| '''Full mission <i>I</i>, 143 GHz.'''<br />
File: SkyMap217e.png| '''Full mission <i>I</i>, 217 GHz.'''<br />
File: SkyMap353e.png| '''Full mission <i>I</i>, 353 GHz.'''<br />
File: SkyMap545e.png| '''Full mission <i>I</i>, 545 GHz.'''<br />
File: SkyMap857e.png| '''Full mission <i>I</i>, 857 GHz.'''<br />
</gallery><br />
</center><br />
<br><br />
<center><br />
<gallery style="padding:0 0 0 0;" perrow=3 widths=260px heights=160px> <br />
File: LFI_SkyMap_030_1024_R2.01_full_Qb_sm1deg.png| '''Full mission <i>Q</i>, 30 GHz.'''<br />
File: LFI_SkyMap_044_1024_R2.01_full_Qb_sm1deg.png | '''Full mission <i>Q</i>, 44 GHz.'''<br />
File: LFI_SkyMap_070_1024_R2.01_full_Qb_sm1deg.png | '''Full mission <i>Q</i>, 70 GHz.'''<br />
File: HFI_Skymap_100_full_bplcorrected_sm1deg_Qb.png | '''Full mission <i>Q</i>, 100 GHz.'''<br />
File: HFI_Skymap_143_full_bplcorrected_sm1deg_Qb.png | '''Full mission <i>Q</i>, 143 GHz.'''<br />
File: HFI_Skymap_217_full_bplcorrected_sm1deg_Qb.png | '''Full mission <i>Q</i>, 217 GHz.'''<br />
File: HFI_Skymap_353_full_bplcorrected_sm1deg_Qb.png | '''Full mission <i>Q</i>, 353 GHz.'''<br />
</gallery><br />
</center><br />
<br><br />
<center><br />
<gallery style="padding:0 0 0 0;" perrow=3 widths=260px heights=160px> <br />
File: LFI_SkyMap_030_1024_R2.01_full_Ub_sm1deg.png| '''Full mission <i>U</i>, 30 GHz.'''<br />
File: LFI_SkyMap_044_1024_R2.01_full_Ub_sm1deg.png | '''Full mission <i>U</i>, 44 GHz.'''<br />
File: LFI_SkyMap_070_1024_R2.01_full_Ub_sm1deg.png | '''Full mission <i>U</i>, 70 GHz.'''<br />
File: HFI_Skymap_100_full_bplcorrected_sm1deg_Ub.png | '''Full mission <i>U</i>, 100 GHz.'''<br />
File: HFI_Skymap_143_full_bplcorrected_sm1deg_Ub.png | '''Full mission <i>U</i>, 143 GHz.'''<br />
File: HFI_Skymap_217_full_bplcorrected_sm1deg_Ub.png | '''Full mission <i>U</i>, 217 GHz.'''<br />
File: HFI_Skymap_353_full_bplcorrected_sm1deg_Ub.png | '''Full mission <i>U</i>, 353 GHz.'''<br />
</gallery><br />
<br />
</center><br />
<br />
=== Full mission light maps, full channel maps (7 HFI, 7 LFI)===<br />
<br />
These maps are based on the Full mission maps but contain fewer columns, IQU from 30 to 353 GHz, and I only at 545 and 857 GHz. These maps have been produced to reduce the transfer time of the most downloaded frequency full mission maps.<br />
<br />
=== Single-survey, full-channel maps (35 LFI)===<br />
<br />
Single-survey maps are built using all valid detectors of a frequency channel; they separately cover the different sky surveys. The surveys are defined as the times over which the satellite spin axis rotates by 180&deg;, which, due to the position of the detectors in the focal plane does not cover the full sky, but a fraction between about 80% and 90%, depending on detector position. During adjacent surveys the sky is scanned in opposite directions (more precisely it is the ecliptic equator that is scanned in opposite directions). While these are useful to investigate variable sources, they are also used to study the systematics of the time-response of the detectors as they scan bright sources, like the Galactic Plane, in different directions during different survey. Note that the HFI and LFI missions cover five and eight surveys, respectively, and in the case of HFI the last survey in incomplete.<br />
The 70 GHz survey maps are available also at <i>N</i><sub>side</sub>=2048. Note that LFI provides a special survey-map combination used in the low-&#8467; analysis; this maps, available at the three LFI frequencies, 30, 44, and 70 GHz, was built using the combination of Surveys 1, 3, 5, 6, 7, and 8.<br />
<br />
=== Year maps, full-channel maps (16 LFI)===<br />
<br />
These maps are built using the data of Surveys 1+2, Surveys 3+4, and so forth. They are used to study long-term systematic effects. The 70 GHz years maps are available also at <i>N</i><sub>side</sub>=2048.<br />
<br />
===Half-mission maps, full-channel maps (14 HFI, 12 LFI)===<br />
<br />
For HFI, the half mission is defined after eliminating those rings that are discarded for all bolometers, many of which occurred during the 5th survey when the "End-of-Life" tests were performed. The remaining rings are divided in half to define the two halves of the mission. This exercise is done for the full mission only.<br />
<br />
For LFI, instead of the half-mission maps, the following year combinations have been created: Year 1+2, Year 1+3, Year 2+4, Year 3+4,<br />
<br />
===Full mission, single-detector maps (22 LFI)===<br />
<br />
For LFI, all the 22 Radiometers maps are available, and (obviously) only in Stokes <i>I</i>.<br />
<br />
===Full-mission, detector-set or detector-pairs maps (8 LFI)===<br />
<br />
The objective here is to build independent temperature (<i>I</i>) and polarization (<i>Q</i> and <i>U</i>) maps using the two pairs of polarization-sensitive detectors of each channel where they are available, i.e., for the 44-353 GHz channels. The table below indicates which detectors were used to build each detector set (detset).<br />
<br />
{| border="1" cellpadding="3" cellspacing="0" align="center" style="text-align:left" width=600px<br />
|+ '''Definition of LFI detector pairs'''<br />
|- bgcolor="ffdead" <br />
!Frequency || Horn pair || Comment <br />
|-<br />
|44 GHz || 24 || This map is only in temperature<br />
|-<br />
|44 GHz || 25 and 26 || <br />
|-<br />
|70 GHz || 18 and 23 || Available also at <i>N</i><sub>side</sub>=2048<br />
|-<br />
|70 GHz || 19 and 22 || Available also at <i>N</i><sub>side</sub>=2048<br />
|-<br />
|70 GHz || 20 and 21 || Available also at <i>N</i><sub>side</sub>=2048<br />
|}<br />
<br />
===Half-ring maps (62 LFI)===<br />
<br />
These maps are similar to the ones described above, but are built using only the first or the second halves of each ring (or pointing period). The HFI provides half-ring maps for the full mission only, as well as for the full channel, the detsets, and the single bolometers. The LFI provides half-ring maps for the full mission in each channel (70 GHz also at <i>N</i><sub>side</sub>=2048), for the full-mission radiometers, and for the full-mission horn pairs.<br />
<br />
=== Odd and even rings maps (14 HFI)<br />
<br />
As the name indicates, these are generated by using only the odd or only the even rings.<br />
<br />
=== Caveats and known issues ===<br />
<br />
'''TBC'''<br />
<br />
==== Caveats when using the HFI frequency maps ====<br />
Some imperfections have shown up in the tests of the HFI PR3 maps that were previously hidden by higher-level systematics in the previous PR2 data. These lead to guidelines for the proper use of the HFI PR3 data.<br />
<br />
===== Monopoles =====<br />
Monopoles, which cannot be extracted from Planck data alone, are adjusted at each frequency (as was done in the previous PR2 release). For component separation, this provides maps that can be used directly in combination with other tracers.<br />
This monopole includes a CIB model, a diffuse ISM signal adjusted on the HI tracer, and a zodiacal emission signal adjusted to the proper absolute intensity.<br />
<br />
=====Use of the 353 GHz SWBs ===== <br />
We deliver two data sets: the recommended one not using the 353 GHz SWBs data, and the other one including the 353 GHz SWBs for specific use like, for example, increasing the signal to noise level at high multipoles.<br />
<br />
===== Color correction and component separation=====<br />
Different responses between bolometers to different foregrounds cannot be used with the PR3 release to extract component maps. Single bolometer maps computed by Sroll in a frequency band, are all adjusted by construction to the band average response.<br />
<br />
===== Sub-pixel effect in very bright regions===== <br />
The bandpass corrections have been optimized for high latitude regions which implied to reduce the noise of the CO and dust bandpass templates to avoid the introduction of significant correlated noise. The effect is negligible for dust but not for CO in very bright regions. See [[subpixel_HFI|detailled description]].<br />
<br />
===== Solar dipole residual===== <br />
The ''Planck'' 2015 Solar dipole is removed from the PR3 HFI maps to be consistent with LFI maps and to facilitate comparison with the previous PR2 ones. The best Solar dipole determination from HFI PR3 data shows a small shift in direction of about 1', but a 1.8 &mu;K lower amplitude. Removal of the ''Planck'' 2015 Solar dipole thus leaves a small but non-negligible dipole residual in the HFI PR3 maps. To correct for this, and adjust maps at the best photometric calibration, users of the HFI PR3 maps should:<br />
# put back into the maps the ''Planck'' 2015 Solar dipole (d,l,b)= (3364.5 &plusmn; 2.0 &mu;K, 264.00 &plusmn; 0.03&deg;, 48.24 &plusmn; 0.02&deg;),<br />
# include the [[#Calibration accuracy|absolute calibration frequency bias]], i.e., multiply by 1 minus the calibration bias,<br />
# lastly, remove the [[#HFI 2018 Solar dipole|HFI 2018 Solar dipole]].<br />
<br />
<br />
<br />
==Inputs==<br />
=== HFI inputs ===<br />
<br />
The HFI mapmaking takes as input:<br />
* the cleaned TOIs of the signal from each detector, together with their flags, produced by the [[TOI processing|TOI processing]] pipeline;<br />
* the TOIs of pointing (quaternions), described in [[Detector_pointing|Detector pointing]];<br />
* bolometer-level characterization data, from the DPC's internal IMO (not distributed);<br />
* Planck orbit data, used to compute and remove the Earth's dipole;<br />
* Planck solar dipole information, used to calibrate the CMB channels;<br />
* planet models used to calibrate the Galactic channels.<br />
<br />
=== LFI inputs ===<br />
<br />
The MADAM mapmaker takes as input:<br />
* the calibrated timelines (for details see [[TOI processing LFI|TOI Processing]]);<br />
* the detector pointings (for details see [[Detector_pointing|Detector pointing]]);<br />
* the noise information in the form of 3-parameter (white noise level &sigma;, slope, and knee frequency <i>f</i><sub>knee</sub>) noise model (for details see [[The RIMO|RIMO]]).<br />
<br />
==Related products==<br />
=== Masks ===<br />
This section presents the "general purpose" masks. Other masks specific to certain products are packaged with those products.<br />
<br />
Note that for this release, HFI has not produced any new masks. <br />
<br />
==== Gatactic Centre masks ====<br />
<br />
'''TBW'''<br />
<br />
<br />
====Point source masks [TO BE REMOVED ??]====<br />
<br />
For HFI and LFI two sets of point-source masks are provided. <br />
* Intensity masks, which remove sources detected with S/N > 5. <br />
* Polarisation masks, which remove sources that have polarization detection significance levels of 99.97 % or greater at the position of a source detected in intensity. They were derived from the polarization maps with dust foreground bandpass mismatch leakage corrections applied. The area excised around each source has a radius of 3σ (width) of the beam, i.e., 1.27 FWHM (for LFI the cut around each source has a radius of 32 arcmin at 30GHz, 27 arcmin at 44 GHz, and 13 arcmin at 70 GHz).<br />
<br />
Both sets of masks are found in the files ''HFI_Mask_PointSrc_2048_R2.00.fits'' and ''LFI_Mask_PointSrc_2048_R2.00.fits'', in which the first extension contains the intensity masks, and the second contains the polarization masks.<br />
<br />
====Galactic plane masks [TO BE REMOVED ??]====<br />
<br />
Eight Galactic emission masks are provided, giving 20, 40, 60, 70, 80, 90, 97, and 99% sky coverage, derived from the 353 GHz map after CMB subtraction. These are independent of frequency channel. Three versions are given: not apodized; and apodized by 2&deg; and 5&deg;. The filenames are ''HFI_Mask_GalPlane-apoN_2048_R2.00.fits'', where <i>N</i> = 0, 2, and 5.<br />
<br />
The masks are shown below. The eight "GalPlane" masks are combined (added together) and shown in a single figure for each of the three apodizations. While the result is quite clear for the case of no apodization, it is less so for the apodized case. The "PointSrc" masks are shown separately for the intensity case.<br />
<br />
<center><br />
<gallery perrow=3 widths=260px heights=160px ><br />
File: GalPlaneMask_apo0.png | '''Galactic plane masks, no apodization.'''<br />
File: GalPlaneMask_apo2.png | '''Galactic plane masks, apodized to 2&deg;.'''<br />
File: GalPlaneMask_apo5.png | '''Galactic plane masks, apodized to 5&deg;.'''<br />
File: PointSrcMask_100.png | '''Point source mask, 100 GHz.'''<br />
File: PointSrcMask_143.png | '''Point source mask, 143 GHz.'''<br />
File: PointSrcMask_217.png | '''Point source mask, 217 GHz.'''<br />
File: PointSrcMask_353.png | '''Point source mask, 343 GHz.'''<br />
File: PointSrcMask_545.png | '''Point source mask, 545 GHz.'''<br />
File: PointSrcMask_857.png | '''Point source mask, 857 GHz.'''<br />
</gallery><br />
</center><br />
<br />
== File names ==<br />
The FITS filenames are of the form ''{H|L}FI_SkyMap_fff{-tag}_Nside_R2.nn_{coverage}-{type}.fits'', where "fff" are three digits to indicate the Planck frequency band, "tag" indicates the single detector or the detset (no "tag" indicates full channel), "Nside" is the HEALPix <i>N</i><sub>side</sub> value of the map, "coverage" indicates which part of the mission is covered (full, half mission, survey, year, etc.), and the optional "type" indicates the subset of input data used. The table below lists the products by type, with the appropriate unix wildcards that form the full filename.<br />
<br />
{| class="wikitable" align="center" style="text-align"left" border="1" cellpadding="15" cellspacing="20" width=880px<br />
|+ '''HFI FITS filenames'''<br />
|- bgcolor="ffdead"<br />
! Coverage || Filename <br />
|-<br />
| Full channel, full mission ||HFI_SkyMap_fff{-tag}_2048_R3.??_full.fits<br />
|-<br />
| Full channel, half mission || HFI_SkyMap_fff{-tag}_2048_R3.??_halfmission-{1/2}.fits<br />
|-<br />
| Full channel, full mission, odd/even ring || HFI_SkyMap_fff{-tag}_2048_R3.??_{odd/even}ring.fits <br />
|}<br />
<br />
{| class="wikitable" align="center" style="text-align"left" border="1" cellpadding="15" cellspacing="20" width=1000px<br />
|+ '''LFI FITS filenames'''<br />
|- bgcolor="ffdead"<br />
! Coverage || Filename || Half-ring filename || Comment<br />
|-<br />
| Full channel, full mission ||LFI_SkyMap_???_1024_R2.??_full.fits ||LFI_SkyMap_???_1024_R2.??_full-ringhalf-?.fits || Available also at Nside = 2048<br />
|-<br />
| Full channel, single survey || LFI_SkyMap_???_1024_R2.??_survey-?.fits || n/a || Available also at <i>N</i><sub>side</sub>=2048<br />
|-<br />
| Full channel, survey combination || LFI_SkyMap_???_1024_R2.??_survey-1-3-5-6-7-8.fits || n/a || n/a<br />
|-<br />
| Full channel, single year || LFI_SkyMap_???_1024_R2.??_year-?.fits || n/a || Available also at <i>N</i><sub>side</sub>=2048<br />
|-<br />
| Full channel, year combination || LFI_SkyMap_???_1024_R2.??_year?-?.fits || n/a || n/a<br />
|-<br />
| Horn pair, full mission || LFI_SkyMap_???-??-??_1024_R2.??_full.fits || LFI_SkyMap_???_??-??_1024_R2.??_full-ringhalf-?.fits || Available also at <i>N</i><sub>side</sub>2048<br />
|-<br />
| Single radiometer, full mission || LFI_SkyMap_???-???_1024_R2.??_full.fits || LFI_SkyMap_???-???_1024_R2.??_full-ringhalf-?.fits || n/a<br />
|}<br />
<br />
For the benefit of users who are only looking for the frequency maps with no additional information, we also provide a file combining the nine frequency maps as separate columns in a single extension. The nine columns in this file contain the intensity maps <i>only</i> and no other information (hits maps or variance maps) is provided.<br />
<br />
== FITS file structure ==<br />
<br />
The FITS files for the sky maps contain a minimal primary header with no data, and a ''BINTABLE'' extension (EXTENSION 1, EXTNAME = ''FREQ-MAP'') containing the data. The structure is shown schematically in the figure below. The ''FREQ-MAP'' extension contains a 3- or 10-column table that contain the signal, hit-count, and variance maps, all in HEALPix format. The 3-column case is for intensity only maps, while the 10-column case is for polarization. The number of rows is the number of map pixels, which is <i>N</i><sub>pix</sub> = 12 <i>N</i><sub>side</sub><sup>2</sup> for HEALPix maps, where <i>N</i><sub>side</sub> = 1024 or 2048 for most the maps presented in this section.<br />
<br />
[[File:FITS_FreqMap.png | 550px | center | thumb | '''FITS file structure.''']]<br />
<br />
Note that file sizes are approximately 0.6 GB for <i>I</i>-only maps and 1.9 GB for <i>IQU</i> maps at <i>N</i><sub>side</sub>=2048, but about 0.14 GB for <i>I</i>-only maps and 0.45 GB for <i>IQU</i> maps at <i>N</i><sub>pix</sub>=1024 .<br />
<br />
Keywords indicate the coordinate system ("GALACTIC"), the HEALPix ordering scheme ("NESTED"), the units (K<sub>CMB</sub> or MJy.sr<sup>-1</sup>) of each column, and of course the frequency channel ("FREQ"). Where polarization <i>Q</i> and <i>U</i> maps are provided, the "COSMO" polarization convention (used in HEALPix) is adopted, and it is specified in the "POLCCONV" keyword (see [[Sky_temperature_maps#Polarization_convention_used_in_the_Planck_project|this section]]). The "COMMENT" fields give a one-line summary of the product, and some other information useful for traceability within the DPCs. The original filename is also given in the "FILENAME" keyword. The "BAD_DATA" keyword gives the value used by HEALPix to indicate pixels for which no signal is present (these will also have a hit-count value of 0). The main parameters are summarized in the table below.<br />
<br />
{| border="1" cellpadding="3" cellspacing="0" align="center" style="text-align:left" width=800px<br />
|+ '''Sky map file data structure'''<br />
|- bgcolor="ffdead" <br />
!colspan="4" | 1. EXTNAME = 'FREQ-MAP' : Data columns<br />
|- bgcolor="ffdead" <br />
! Column name || Data type || Units || Description<br />
|-<br />
|I_STOKES || Real*4 || K<sub>CMB</sub> or MJy.sr<sup>-1</sup> || Stokes <i>I</i> map<br />
|-<br />
|Q_STOKES || Real*4 || K<sub>CMB</sub> or MJy.sr<sup>-1</sup> || Stokes <i>Q</i> map (optional)<br />
|-<br />
|U_STOKES || Real*4 || K<sub>CMB</sub> or MJy.sr<sup>-1</sup> || Stokes <i>U</i> map (optional)<br />
|-<br />
|HITS || Int*4 || none || The hit-count map<br />
|-<br />
|II_COV || Real*4 || K<sub>CMB</sub><sup>2</sup> or (MJy.sr<sup>-1</sup>)<sup>2</sup> || <i>II</i> variance map<br />
|-<br />
|IQ_COV || Real*4 || K<sub>CMB</sub><sup>2</sup> or (MJy.sr<sup>-1</sup>)<sup>2</sup> || <i>IQ</i> variance map (optional)<br />
|-<br />
|IU_COV || Real*4 || K<sub>CMB</sub><sup>2</sup> or (MJy.sr<sup>-1</sup>)<sup>2</sup> || <i>IQ</i> variance map (optional)<br />
|-<br />
|QQ_COV || Real*4 || K<sub>CMB</sub><sup>2</sup> or (MJy.sr<sup>-1</sup>)<sup>2</sup> || <i>QQ</i> variance map (optional)<br />
|-<br />
|QU_COV || Real*4 || K<sub>CMB</sub><sup>2</sup> or (MJy.sr<sup>-1</sup>)<sup>2</sup> || <i>QU</i> variance map (optional)<br />
|-<br />
|UU_COV || Real*4 || K<sub>CMB</sub><sup>2</sup> or (MJy.sr<sup>-1</sup>)<sup>2</sup> || <i>UU</i> variance map (optional)<br />
|-<br />
|- bgcolor="ffdead" <br />
! Keyword || Data type || Value || Description<br />
|-<br />
|PIXTYPE || String || HEALPIX ||<br />
|-<br />
|COORDSYS || String || GALACTIC ||Coordinate system <br />
|-<br />
|ORDERING || String || NESTED || Healpix ordering<br />
|-<br />
|POLCCONV || String || COSMO || Polarization convention<br />
|-<br />
|NSIDE || Int || 1024 or 2048 || HEALPix <i>N</i><sub>side</sub> <br />
|-<br />
|FIRSTPIX || Int*4 || 0 || First pixel number<br />
|-<br />
|LASTPIX || Int*4 || 12 <i>N</i><sub>side</sub><sup>2</sup> – 1 || Last pixel number<br />
|-<br />
|FREQ || String || nnn || Frequency channel <br />
|}<br />
<br />
<br />
The same structure applies to all "SkyMap" products, independent of whether they are full channel, survey of half-ring. The distinction between the types of maps is present in the FITS filename (and in the traceability comment fields).<br />
<br />
==Polarization convention used in the Planck project==<br />
<br />
The FITS keyword "POLCCONV" defines the polarization convention of the data within the file.<br />
The Planck collaboration used the COSMO convention for the polarization angle (as usually adopted in space-based and other CMB missions), whereas other subfields of astronomy usually adopt the IAU convention. The basic difference comes down to whether one thinks of the light rays being emitted from the origin (the usual mathematics/physics convention) or converging on the observer from the sky (the usual astronomy convention), and hence the "obvious" choice is different for a physicists and for an astronomer. Given that CMB results are of interest to a wide range of both physicists and astronomers, there is no single choice of convention that everyone would regard as self-evident. Hence one simply has to be aware of the convention being adopted. Because of this the Planck Collaboration has taken pains to point out which convention is being used in publications and in data releases. In the following we describe the difference between these two conventions, and the consequence if it is <i>not</i> taken into account correctly in the analysis.<br />
<br />
[[File:conventions.png|thumb|center|400px|'''Figure 1. Polarization conventions, showing the COSMO convention (left) and IAU convention (right). The vector <math>\hat{z}</math> points in the outward direction in COSMO, and inwards in IAU. The bottom panel refers to the plane tangent to the sphere.''']]<br />
<br />
Changing the orientation convention is equivalent to a transformation &psi;'=&pi;-&psi; of the polarization angle (Figure 1). The consequence of this transformation is the inversion of the Stokes parameter <i>U</i>.<br />
The components of the polarization tensor in the helicity basis <math>\epsilon^{\pm}=(\hat{x}\pm i\hat{y})/\sqrt{2}</math> are<br />
<br />
<math><br />
(Q+iU)(\hat{n}) = \sum _{\ell m}a_{2,lm}{}_{2}Y_{\ell }^{m}(\hat{n}),<br />
\\(Q-iU)(\hat{n}) = \sum _{\ell m}a_{-2,lm}{}_{2}Y_{\ell }^{m}(\hat{n}),<br />
</math><br />
<br />
where <math>{}_{2}Y_{\ell }^{m}(\hat{n})</math> are the spin-weighted spherical harmonic functions.<br />
The <i>E</i> and <i>B</i> modes can be defined as<br />
<br />
<math><br />
E(\hat{n}) = \sum_{\ell m}a_{E,\ell m}Y_{\ell }^{m}(\hat{n}),<br />
\\B(\hat{n}) = \sum_{\ell m}a_{B,\ell m}Y_{\ell }^{m}(\hat{n}),<br />
</math><br />
<br />
where the coefficients <i>a<sub>E,&#8467;m</sub></i> and <i>a<sub>B,&#8467;m</sub></i> are derived from linear combinations of the <i>a<sub>2,&#8467;m</sub></i>, <i>a<sub>-2,&#8467;m</sub></i>, defined implicitly in the first equation (<i>Q</i>&plusmn; i<i>U</i>).<br />
<br />
[[File:test_gradient.jpg|thumb|center|400px|]]<br />
[[File:test_curl.jpg|thumb|center|400px|'''Figure 2. Error on Planck-LFI 70 GHz <i>EE</i> (top) and <i>BB</i> (bottom) power spectra, in the case of an incorrect choice being made for the polarization coordinate system convention (IAU instead of COSMO).''']]<br />
<br />
The effect of the sign inversion of <i>U</i> on the polarization spectra is a non-trivial mixing of <i>E</i> and <i>B</i> modes. <br />
An example of the typical error on <i>EE</i> and <i>BB</i> auto-spectra in the case of the wrong choice for the polarization basis is shown in Figure 2.<br />
<br />
<i>One should be careful</i> to be aware of the polarization convention that is being adopted. If the IAU convention is used in computing the power spectra, then the sign of the <i>U</i> component of the Planck maps must be inverted before computing the <i>E</i> and <i>B</i> modes.<br />
<br />
In astronomical applications it is common to define a pseudo-vector <i>P</i> to show the amplitude and orientation of<br />
polarization on a map. When plotting these line segments to show the orientation of the plane of polarization (or the orthogonal direction, often considered to be the projection of the magnetic field), the results are the same for both the COSMO and IAU conventions. This because the appearance of <i>P</i> is a property of the radiation and hence not affected by the sign of <i>U</i>.<br />
<br />
=== Note on the convention used in the Planck Catalogue of Compact Sources (PCCS) ===<br />
Planck non-cosmology papers sometimes follow the IAU convention for internal analysis, for ease of comparison with other studies (e.g., comparison of Planck-derived thermal dust emission polarization with the optical polarization of starlight). Nevertheless, Planck data products, such as component-separated maps, still use the COSMO convention. The one exception is for the compact source catalogue. Because catalogues of astronomical objects found by Planck need to be compared directly with other source catalogues, the polarized sources described in the Planck Catalogue of Compact Sources follow the IAU convention, and the polarization angles are defined on an interval of [-90&deg;,90&deg;]. To switch to the COSMO convention, the polarization angles listed in the catalogue should be shifted by 90&deg; and multiplied by -1.<br />
<br />
== References ==<br />
<References /><br />
<br />
<br />
<span style="background:green"><br />
<br />
<span style="background:green"><br />
== Previous releases ==<br />
<br />
<div class="toccolours mw-collapsible mw-collapsed" style="background-color: #FFDAB9;width:80%" ><br />
'''2015 Sky temperature and polarization maps'''<br />
<br />
<div class="mw-collapsible-content"><br />
<br />
<br />
'''General description'''<br />
<br />
Sky maps give the best estimate of the intensity and polarization (Stokes Q and U components), if available, of the signal from the sky after removal, as far as possible, of known systematic effects (mostly instrumental, but including also the solar and earth-motion dipole, Galactic strylight and the Zodiacal light). Sky maps are provided for the full Planck mission using all valid detectors in each frequency channel, and also for various subsets by splitting the mission in various time ranges or in subsets of the detectors in a given channel. These products are useful for the study of source variability, but they are especially interesting for characterisation purposes (see also the [[HFI-Validation | data validation]] section). The details of the start and end of the time ranges are given in the table below.<br />
<br />
To help in further processing, there are also masks of the Galactic Plane and of point sources, each provided for several different depths.<br />
<br />
All sky maps are in Healpix format, with Nside of 1024 (LFI 30, 44 and 70) and 2048 (LFI 70 and HFI), in Galactic coordinates, and Nested ordering. <br />
<br />
;WARNING: the Healpix convention for polarization is NOT the same as the IAU convention - see Section 8 in this page.<br />
<br />
The signal is given in units of K<sub>cmb</sub> for 30-353 GHz, and of MJy/sr (for a constant <math>\nu F_\nu</math> energy distribution ) for 545 and 857 GHz. For each frequency channel, the intensity and polarization maps are packaged into a ''BINTABLE'' extension of a FITS file together with a hit-count map (or hit map, for short, giving the number of observation samples that are cumulated in a pixel, all detectors combined) and with the variance and covariance maps. Additional information is given in the FITS file header. The structure of the FITS file is given in the [[#FITS_file_structure | FITS file structure]] section below. <br />
<br />
; R2.00 : this first release (Jan 2015) contains polarisation data for the 353 GHz channel only.<br />
; R2.01 : this second release (May 2015) adds polarisation data to the 100-217 GHz channels.<br />
; R2.02 : a full re-release to correct the Healpix bad pixel value in the maps which was altered during the preparation of the maps and not reset to the correct value (the valid pixels are unchanged). It also fixes some FITS keywords, and includes a full re-release of the Zodi correction maps, with the 100-217 GHz one now including the polarisation correction)<br />
<br />
{| border="1" cellpadding="3" cellspacing="0" align="center" style="text-align:left" width=800px<br />
|+ '''Ranges for mission and surveys'''<br />
|- bgcolor="ffdead" <br />
! Range || ODs || HFI rings || pointing-IDs || Comment<br />
|-<br />
|nominal mission || 91 - 563 || 240 - 14723 || 00004200 - 03180200 ||<br />
|-<br />
|full mission || 91 - 974 || 240 - 27005 || 00004200 - 05322620 || for HFI<br />
|-<br />
|full mission || 91 - 1543 || n/a || 00004200 - 06511160 || for LFI<br />
|-<br />
|Survey 1 || 91 - 270 || 240 - 5720 || 00004200 - 01059820 ||<br />
|-<br />
|Survey 2 || 270 - 456 || 5721 - 11194 || 01059830 - 02114520 ||<br />
|-<br />
|Survey 3 || 456 - 636 || 11195 - 16691 || 02114530 - 03193660 ||<br />
|-<br />
|Survey 4 || 636 - 807 || 16692 - 21720 || 03193670 - 04243900 ||<br />
|-<br />
|Survey 5 || 807 - 974 || 21721 - 27005 || 05267180 - 05322590 || end of mission for HFI<br />
|-<br />
|Survey 5 || 807 - 993 || n/a || 05267180 - 06344800 || end of survey for LFI<br />
|-<br />
|Survey 6 || 993 - 1177 || n/a || 06344810 - 06398120 || LFI only <br />
|-<br />
|Survey 7 || 1177 - 1358 || n/a || 06398130 - 06456410 || LFI only <br />
|-<br />
|Survey 8 || 1358 - 1543 || n/a || 06456420 - 06511160 || LFI only <br />
|-<br />
|Survey 9 || 1543 - 1604 || n/a || 06511170 - 06533320 || LFI only Not in this delivery<br />
|-<br />
|HFI mission-half-1 || 91 - 531 || 240 - 13471 || 00004200 - 03155580 ||<br />
|-<br />
|HFI mission-half-2 || 531 - 974 || 13472 - 27005 || 03155590 - 05322590 ||<br />
|-<br />
|LFI Year 1 || 91 - 456 || n/a || 00004200 - 02114520 ||<br />
|-<br />
|LFI Year 2 || 456 - 807 || n/a || 02114530 - 04243900 ||<br />
|-<br />
|LFI Year 3 || 807 - 1177 || n/a || 05267180 - 06398120 ||<br />
|-<br />
|LFI Year 4 || 1177 - 1543 || n/a || 06398130 - 06511160 ||<br />
|-<br />
|}<br />
<br />
'''Production process'''<br />
<br />
Sky maps are produced by combining appropriately the data of all working detectors in a frequency channel over some period of the mission. They give the best estimate of the signal from the sky (unpolarised) after removal, as far as possible, of known systematic effects and of the dipole signals induced by the motion of the solar system in the CMB and of the Planck satellite in the solar system. In particular, they include the Zodiacal light emission (Zodi for short) and also the scattering from the far-side lobes of the beams (FSL). More on this below.<br />
<br />
''' HFI processing '''<br />
<br />
The mapmaking and calibration process is described in detail in the [[Map-making_LFI | Map-making]] section and in the {{PlanckPapers|planck2014-a09}} paper, where detailed references are found. In brief it consists of:<br />
<br />
; binning the TOI data onto ''rings'' : Healpix rings (HPRs) are used here, each ring containing the combined data of one pointing period. <br />
; flux calibration : at 100-353 GHz, the flux calibration factors are determined by correlating the signal with the orbital dipole, which is determined very accurately from the Planck satellite orbital parameters provided by Flight Dynamics. This provides a single gain factor per bolometer. At 545 and 857 GHz the gain is determined from the observation of Uranus and Neptune (but not Jupiter which is too bright) and comparison to recent models made explicitly for this mission. A single gain is applied to all rings at these frequencies.<br />
; destriping : in order to remove low-frequency noise, an offset per ring is determined by minimizing the differences between HPRs at their crossings, and removed.<br />
; Zodiacal light correction : a Zodiacal light model is used to build HPRs of the the Zodi emission, which is subtracted from the calibrated HPRs.<br />
; projection onto the map : the offset-corrected, flux-calibrated, and Zodi-cleaned HPRs are projected onto Healpix maps, with the data of each bolometer weighted by a factor of 1/NET of that bolometer.<br />
<br />
These steps are followed by some post-processing which is designed to prepare the maps for the component separation work. This post processing consists of: <br />
<br />
; Dust bandpass leakage correction : the Q and U maps are corrected for the intensity-to-polarisation leakage caused by the foregrounds having a non-CMB spectrum, and as a consequence of the non-identical bandpasses on the different detectors (bandpass mismatch, or BPM). This correction is determined using the ''ground'' method as described in Section 7.3 of {{PlanckPapers|planck2014-a09}}. These correction maps can be found in the Planck Legacy Archive as ''HFI_CorrMap_???-dustleak-ground_2048_R2.0?_{coverage}.fits''. The correction is applied by subtracting the correction map from the corresponding input map. This correction is not applied to the nominal mission maps in order to maintain compatibility with the PR1 products. ''In fact this correction was computed and applied only to the products used in component separation'', so they were not applied to the single survey maps and to the half-ring maps, which are considered characterisation products.<br />
; Far Side Lobe calibration correction : the 100-217 maps are multiplied by factors of 1.00087, 1.00046, and 1.00043, respectively, to compensate for the non-removal of the far-side lobes, and similarly the corresponding covariance maps have also been corrected by multiplication by the square of the factor.<br />
; Fill missing pixels : missing pixels are filled in with a value that is the mean of valid pixels within a given radius. A radius of 1 deg is used for the full channel maps, and 1.5 deg is used for the detset maps. This step is not applied to the single survey maps since they have large swaths of the sky that are not covered.<br />
<br />
; Map zero-level : for the 100 to 857 GHz maps, the zero levels are set to their optimal levels for Galactic and CIB studies. A procedure for adjusting them to astrophysical values is given in the HFI Mapmaking and Calibration paper {{PlanckPapers|planck2014-a09}}.<br />
<br />
These maps provide the main mission products. Together with signal maps, hit count, variance, and variance maps are also produced. The hit maps give the (integer) number of valid TOI-level samples that contribute to the signal of each pixel. All valid samples are counted in the same way, i.e., there is no weighting factor applied. The variance maps project the white noise estimate, provided by the NETs, in the sky domain.<br />
<br />
Note that the nominal mission maps have not had the post-processing applied, which makes them more easily comparable to the PR1 products.<br />
<br />
''' LFI processing '''<br />
LFI maps were constructed with the Madam map-making code, version 3.7.4. The code is based on generalized destriping technique, where the correlated noise component is modeled as a sequence of constant offset, called baselines. A noise filter was used to constrain the baseline solution allowing the use of 0.25 s and 1 second baselines for the 30 and 44, 70 GHz respectively.<br />
<br />
Radiometers were combined according to the horn-uniform weighting scheme to minimize systematics. The used weights are listed in [[Map-making LFI#Map-making|Map-making]]. The flagged samples were excluded from the analysis by setting their weights to <math>C_{w}^{-1}</math> = 0. The galaxy region was masked out in the destriping phase, to reduce error arising from strong signal gradients. The polarization component was included in the analysis... <br />
<br />
; Dipole and Far Side Lobe correction : input timelines are cleaned by 4pi convolved dipole and Galactic Straylight obtained as convolution of the 4pi in band far sidelobes and Galactic Simulation as explained in Section 7.4 of {{PlanckPapers|planck2014-a03}}. <br />
<br />
Beam effects on the LFI maps are described in Section 7.1 of {{PlanckPapers|planck2014-a03}}. Scaling of the maps due to beam effects is taken into account in the LFI's beam functions (as provided in the RIMO, give reference) which should be used for analysis of diffuse components. To compute the flux densities of compact sources, correction must be made for beam effects (see Table 8 of {{PlanckPapers|planck2014-a03}})."<br />
<br />
; Bandpass leakage correction : '''as opposed to the HFI, the LFI high resolution maps have not been corrected for bandpass leakage. Only low resolution (nside 256) maps are provided with the bandpass correction'''. The correction maps (LFI_CorrMap_0??-BPassCorr_*.fits) can be found in the Planck Legacy Archive. Further details about the procedure used to generate the bandpass correction maps can be found in Section 11 of {{PlanckPapers|planck2014-a03}}.<br />
<br />
; Map zero-level : for the 30, 44 and 70 GHz, maps are corrected for zero level monopole by applying an offset correction, see LFI Calibration paper {{PlanckPapers|planck2014-a06}}. Note that the offset applied is indicated in the header as a comment keyword.<br />
<br />
A detailed description of the map-making procedure is given in {{PlanckPapers|planck2013-p02}}, {{PlanckPapers|planck2014-a03}}, {{PlanckPapers|planck2014-a07}} and in section [[Map-making LFI#Map-making|Map-making]].<br />
<br />
'''Types of maps '''<br />
<br />
''' Full mission, full channel maps (6 HFI, 4 LFI)'''<br />
<br />
Full channel maps are built using all the valid detectors of a frequency channel and cover the either the full or the nominal mission. For HFI, the 143-8 and 545-3 bolometers are rejected entirely as they are seriously affected by RTS noise. HFI provides the Q and U components for the 100, 143, 217 and 353 GHz channels only. LFI provides the I, Q and U maps for all the channels. Reminder: HFI Q and U maps are corrected for bandpass leakage but LFI Q and U maps are not. The I, Q and U maps are displayed in the figures below. The color range is set using a histogram equalisation scheme (from HEALPIX) that is useful for these non-Gaussian data fields. For visualization purposes, the Q and U maps shown here have been smoothed with a 1 degree Gaussian kernel, otherwise they look like noise to the naked eye.<br />
The 70 GHz full map is available also at <math>N_{side}</math> 2048.<br />
<br />
<center><br />
<gallery style="padding:0 0 0 0;" perrow=3 widths=260px heights=160px> <br />
File: SkyMap30e.png| '''Full mission I, 30 GHz'''<br />
File: SkyMap44e.png | '''Full mission I, 44 GHz'''<br />
File: SkyMap70e.png | '''Full mission I, 70 GHz'''<br />
File: SkyMap100e.png | '''Full mission I, 100 GHz'''<br />
File: SkyMap143e.png | '''Full mission I, 143 GHz'''<br />
File: SkyMap217e.png | '''Full mission I, 217 GHz'''<br />
File: SkyMap353e.png | '''Full mission I, 353 GHz'''<br />
File: SkyMap545e.png | '''Full mission I, 545 GHz'''<br />
File: SkyMap857e.png | '''Full mission I, 857 GHz'''<br />
</gallery><br />
</center><br />
<br><br />
<center><br />
<gallery style="padding:0 0 0 0;" perrow=3 widths=260px heights=160px> <br />
File: LFI_SkyMap_030_1024_R2.01_full_Qb_sm1deg.png| '''Full mission Q, 30 GHz'''<br />
File: LFI_SkyMap_044_1024_R2.01_full_Qb_sm1deg.png | '''Full mission Q, 44 GHz'''<br />
File: LFI_SkyMap_070_1024_R2.01_full_Qb_sm1deg.png | '''Full mission Q, 70 GHz'''<br />
File: HFI_Skymap_100_full_bplcorrected_sm1deg_Qb.png | '''Full mission Q, 100 GHz'''<br />
File: HFI_Skymap_143_full_bplcorrected_sm1deg_Qb.png | '''Full mission Q, 143 GHz'''<br />
File: HFI_Skymap_217_full_bplcorrected_sm1deg_Qb.png | '''Full mission Q, 217 GHz'''<br />
File: HFI_Skymap_353_full_bplcorrected_sm1deg_Qb.png | '''Full mission Q, 353 GHz'''<br />
</gallery><br />
</center><br />
<br><br />
<center><br />
<gallery style="padding:0 0 0 0;" perrow=3 widths=260px heights=160px> <br />
File: LFI_SkyMap_030_1024_R2.01_full_Ub_sm1deg.png| '''Full mission U, 30 GHz'''<br />
File: LFI_SkyMap_044_1024_R2.01_full_Ub_sm1deg.png | '''Full mission U, 44 GHz'''<br />
File: LFI_SkyMap_070_1024_R2.01_full_Ub_sm1deg.png | '''Full mission U, 70 GHz'''<br />
File: HFI_Skymap_100_full_bplcorrected_sm1deg_Ub.png | '''Full mission U, 100 GHz'''<br />
File: HFI_Skymap_143_full_bplcorrected_sm1deg_Ub.png | '''Full mission U, 143 GHz'''<br />
File: HFI_Skymap_217_full_bplcorrected_sm1deg_Ub.png | '''Full mission U, 217 GHz'''<br />
File: HFI_Skymap_353_full_bplcorrected_sm1deg_Ub.png | '''Full mission U, 353 GHz'''<br />
</gallery><br />
<br />
</center><br />
<br />
''' Full mission light maps, full channel maps (6 HFI, 7 LFI) '''<br />
<br />
These maps are based on the Full mission maps but contain fewer columns, IQU from 30 to 353 GHz, and I only at 545 and 857 GHz. These maps have been produced to reduce the transfer time of the most downloaded frequency full mission maps.<br />
<br />
''' Nominal mission, full channel maps (6 HFI) '''<br />
<br />
These maps are similar to the ones above, but cover the nominal mission only. They are meant primarily to be compared to the PR1 products in order to see the level of improvements in the processing. Because of this, they are produced in Temperature only, and have not had the post-processing applied.<br />
<br />
''' Single survey, full channel maps (30 HFI, 35 LFI)'''<br />
<br />
Single survey maps are built using all valid detectors of a frequency channel; they cover separately the different sky surveys. The surveys are defined as the times over which the satellite spin axis rotates but 180 degrees, which, due to the position of the detectors in the focal plane does not cover the full sky, but a fraction between ~80 and 90% depending on detector position. During adjacent surveys the sky is scanned in opposite directions. More precisely it is the ecliptic equator that is scanned in opposite directions. While these are useful to investigate variable sources, they are also used to study the systematics of the time-response of the detectors as they scan bright sources, like the Galactic Plane, in different directions during different survey. Note that the HFI and LFI missions cover 5 and 8 surveys, respectively, and in case of HFI the last survey in incomplete.<br />
The 70 GHz surveys maps are available also at <math>N_{side}</math> 2048.<br />
Note LFI provide a special surveys maps combination used in the low l analysis. This maps, available at the three LFI frequency 30, 44 and 70 GHz, was built using the combination of survey 1, 3, 5, 6, 7 and 8. <br />
<br />
''' Year maps, full channel maps (12 HFI, 16 LFI)'''<br />
<br />
These maps are built using the data of surveys 1+2, surveys 3+4, and so forth. They are used to study long-term systematic effects.<br />
The 70 GHz years maps are available also at <math>N_{side}</math> 2048.<br />
<br />
'''Half-mission maps, full channel maps (12 HFI, 12 LFI)'''<br />
<br />
For HFI, the half mission is defined after eliminating those rings discarded for all bolometers. There are 347 such rings, may of which are during the 5th survey when the ''End-of-Life'' tests were performed. The remaining 26419 rings are divided in half (up to the odd ring) to define the two halves of the mission. This exercise is done for the full mission only.<br />
<br />
For LFI instead of the half-mission the following year combination has been created: Year 1+2, Year 1+3, Year 2+4, Year 3+4, <br />
<br />
'''Full mission, single detector maps (18 HFI, 22 LFI)'''<br />
<br />
IN case of HFI these maps are built only for the SWBs (non polarized) and contain only temperature data, of course. They are not built for the polarisation sensitive detectors because they are not fixed on the sky as the polarisation component depends on the position angle at the time of observation. Instead, we provide maps built by ''quads'' of polarisation-sensitive detectors (see next section), which have different polarisation angles and that can be used to built I, Q, and U maps<br />
<br />
{| border="1" cellpadding="3" cellspacing="0" align="center" style="text-align:left" width=600px<br />
|+ '''HFI Temperature sensitive bolometers'''<br />
|- bgcolor="ffdead" <br />
!Frequency || Detector names<br />
|-<br />
|143 GHz || 143-5, 6, 7<br />
|-<br />
|217 GHz || 217-1, 2, 3, 4<br />
|-<br />
|353 GHz || 353-1, 2, 7, 8<br />
|-<br />
|545 GHz || 545-1, 2, 4<br />
|-<br />
|857 GHz || 857-1, 2 , 3, 4<br />
|}<br />
<br />
The 143-8 and 353-3 bolometer data are affected by strong RTS (random telegraphic signal) noise. They have not been used in the data processing, and are not delivered. For a figure showing the focal plane layout, see [[Detector_pointing#Introduction_and_Summary | this Introduction]] of the Detector Pointing chapter.<br />
<br />
In case of LFI, all the 22 Radiometers maps are available, those, obviously, are only in temperature.<br />
<br />
'''Full mission, detector set or detector pairs maps (8 HFI, 8 LFI)'''<br />
<br />
The objective here is to build independent temperature (I) and polarisation (Q and U) maps with the two pairs of polarisation sensitive detectors of each channel where they are available, i.e. in the 44-353 GHz channels. The table below indicates which detectors were used to built each detector set (detset).<br />
<br />
<br />
{| border="1" cellpadding="3" cellspacing="0" align="center" style="text-align:left" width=600px<br />
|+ '''Definition of HFI Detector Sets'''<br />
|- bgcolor="ffdead" <br />
!Frequency || DetSet1 || DetSet2 <br />
|-<br />
|100 GHz || 100-1a/b & 100-4a/b || 100-2a/b & 100-3a/b<br />
|-<br />
|143 GHz || 143-1a/b 1 & 43-3a/b || 143-2a/b & 143-4a/b<br />
|-<br />
|217 GHz || 217-5a/b & 217-7a/b || 217-6a/b & 217-8a/b<br />
|-<br />
|353 GHz || 353-3a/b & 353-5a/b || 353-4a/b & 353-6a/b<br />
|}<br />
<br />
{| border="1" cellpadding="3" cellspacing="0" align="center" style="text-align:left" width=600px<br />
|+ '''Definition of LFI Detector Pairs'''<br />
|- bgcolor="ffdead" <br />
!Frequency || Horn Pair || Comment <br />
|-<br />
|44 GHz || 24 || This maps is only in temperature<br />
|-<br />
|44 GHz || 25 & 26 || <br />
|-<br />
|70 GHz || 18 & 23 || Available also at <math>N_{side}</math> = 2048<br />
|-<br />
|70 GHz || 19 & 22 || Available also at <math>N_{side}</math> = 2048<br />
|-<br />
|70 GHz || 20 & 21 || Available also at <math>N_{side}</math> = 2048<br />
|}<br />
<br />
<br />
'''Half-ring maps (64 HFI, 62 LFI)'''<br />
<br />
These maps are similar to the ones above, but are built using only the first or the second half of each ring (or pointing period). The HFI provides half-ring maps for the full mission only, and for the full channel, the detsets, and the single bolometers. The LFI provides half-rings maps for the channel full mission (70 GHz also at <math>N_{side}</math> 2048), for the radiometer full mission and the horn pairs full mission.<br />
<!----<br />
'''Masks'''<br />
<br />
Masks are provided of the Galactic Plane and of the point sources. For the Galactic Plane, eight masks are given covering different fractions of the sky, and for the points sources two masks are given, at the 5 and 10 sigma level, for each Planck HFI and LFI frequency channel. These are generic masks, specific masks applicable to other products are delivered with the products themselves.<br />
---><br />
<br />
''' The Zodiacal light correction maps '''<br />
<br />
The Zodiacal light signal depends on the location of the observer relative to the Zodiacal light bands, and thus it is not a fixed pattern on the sky but depends on the period of observation. The maps presented here are the difference between the uncorrected (and not delivered) and the corrected maps. <br />
<br />
Note that while the Zodiacal light model that is subtracted at ring level (see [[Map-making#Zodiacal_light_correction | here]]) is not polarised, the corrections are not null and Q and U. This is suspected to come from some combination of leakage due to bandpass differences and beam mismatch, and maybe other effects. These leakages are typically of order a few %, at max, of the maximum zodi intensity at I for each channel. They range from ~150 nK at 100 GHz to ~5 uK at 353 GHz.<br />
<br />
''' Caveats and known issues '''<br />
<br />
; HFI polarization 100-217 GHz : at low multipoles, despite the progress that has been made to control the systematic effects present in the maps, polarization data between 100-217 GHz are still contaminated by systematic residuals. Figure 10 of {{PlanckPapers|planck2014-a09}} shows the EE power spectra from the half-difference maps at 100, 143, and 217 GHz and compared to the noise power spectrum from FFP8 simulations. he half-ring differences are compatible with noise while, at multipoles typically lower than 50, detector-set and half-mission differences are dominated by excess power which is larger than the EE CMB signal. The Planck Collaboration has used the range ell>30 to carry out component separation ({{PlanckPapers|planck2014-a11}}), as data at ell<30 is not considered usable for cosmological analyses. The origin of the excess power will be explored in a forthcoming publication.<br />
<br />
<br />
'''Inputs'''<br />
''' HFI inputs '''<br />
<br />
The HFI mapmaking takes as input:<br />
* the cleaned TOIs of signal of each detector, together with their flags, produced by the [[TOI processing|TOI processing]] pipeline;<br />
* the TOIs of pointing (quaternions), described in [[Detector_pointing|Detector pointing]];<br />
* bolometer-level characterization data, from the DPC's internal IMO (not distributed);<br />
* Planck orbit data, used to compute and remove the Earth's dipole;<br />
* Planck solar dipole information, used to calibrate the CMB channels;<br />
* Planet models used to calibrate the Galactic channels.<br />
<br />
''' LFI inputs '''<br />
<br />
The Madam mapmaker takes as input:<br />
<br />
* the calibrated timelines (for details see [[TOI processing LFI|TOI Processing]]);<br />
* the detector pointings (for details see [[Detector_pointing|Detector pointing]]);<br />
* the noise information in the form of 3-parameter (white noise level, &sigma;, slope, and knee frequency, <i>f</i><sub>knee</sub>) noise model (for details see [[The RIMO|RIMO]])<br />
<br />
'''Related products'''<br />
''' Masks '''<br />
<br />
This section presents the masks of the point sources and of the Galactic plane. These are ''general purpose'' masks. Other masks specific to certain products are packaged with the products.<br />
<br />
'''Point source masks'''<br />
<br />
For HFI and LFI two sets of masks are provided: <br />
* Intensity masks, which removes sources detected with SNR > 5. <br />
* Polarisation masks, which remove sources which have polarisation detection significance of 99.97 % or greater at the position of a source detected in intensity. They were derived from the polarisation maps with dust ground bandpass mismatch leakage correction applied. The cut around each source has a radius of 3σ (width) of the beam ~ 1.27 FWHM (for LFI the cut around each source has a radius of 32 arcmin at 30GHz, 27 arcmin at 44 GHz and 13 arcmin at 70 GHz).<br />
<br />
Both sets are found in the files ''HFI_Mask_PointSrc_2048_R2.00.fits'' and ''LFI_Mask_PointSrc_2048_R2.00.fits'' in which the first extension contains the Intensity masks, and the second contains the Polarisation masks.<br />
<br />
'''Galactic plane masks'''<br />
<br />
Eight masks are provided giving 20, 40, 60, 70, 80, 90, 97, and 99% sky coverage derived from the 353 GHz map, after CMB subtraction. They are independent of frequency channel. Three versions of these are given: not apodized, and apodized by 2 and 5 deg. The filenames are ''HFI_Mask_GalPlane-apoN_2048_R2.00.fits'', where N = 0, 2, 5.<br />
<br />
The masks are shows below. The 8 GalPlane masks are combined (added together) and shown in a single figure for each of the three apodization. While the result is quite clear for the case of no apodization, it is less so for the apodized case. The point source masks are shown separately for the Intensity case.<br />
<br />
<center><br />
<gallery perrow=3 widths=260px heights=160px ><br />
File: GalPlaneMask_apo0.png | '''Galactic Plane masks, no apod'''<br />
File: GalPlaneMask_apo2.png | '''Galactic Plane masks, apod 2 deg'''<br />
File: GalPlaneMask_apo5.png | '''Galactic Plane masks, apod 5 deg'''<br />
File: PointSrcMask_100.png | '''PointSource mask 100 GHz'''<br />
File: PointSrcMask_143.png | '''PointSource mask 143 GHz'''<br />
File: PointSrcMask_217.png | '''PointSource mask 217 GHz'''<br />
File: PointSrcMask_353.png | '''PointSource mask 343 GHz'''<br />
File: PointSrcMask_545.png | '''PointSource mask 545 GHz'''<br />
File: PointSrcMask_857.png | '''PointSource mask 857 GHz'''<br />
</gallery><br />
</center><br />
<br />
''' File names '''<br />
The FITS filenames are of the form ''{H|L}FI_SkyMap_fff{-tag}_Nside_R2.nn_{coverage}-{type}.fits'', where ''fff'' are three digits to indicate the Planck frequency band, ''tag'' indicates the single detector or the detset, ''Nside'' is the Healpix Nside of the map, ''coverage'' indicates which part of the mission is covered (full, half mission, survey, year, ...) , and the optional ''type'' indicates the subset of input data used. The table below lists the products by type, with the appropriate unix wildcards that form the full filename.<br />
<br />
{| class="wikitable" align="center" style="text-align"left" border="1" cellpadding="15" cellspacing="20" width=880px<br />
|+ '''HFI FITS filenames'''<br />
|- bgcolor="ffdead"<br />
! Coverage || filename || half-ring filename <br />
|-<br />
| Full chan, full mission ||HFI_SkyMap_???_2048_R2.??_full.fits ||HFI_SkyMap_???_2048_R2.??_full-ringhalf-?.fits<br />
|-<br />
| Full channel, nominal mission ||HFI_SkyMap_???_2048_R2.??_nominal.fits || n/a<br />
|-<br />
| Full channel, single survey || HFI_SkyMap_???_2048_R2.??_survey-?.fits || n/a<br />
|-<br />
| Full channel, single year || HFI_SkyMap_???_2048_R2.??_year-?.fits || n/a<br />
|-<br />
| Full channel, half mission || HFI_SkyMap_???_2048_R2.??_halfmission*-?.fits || n/a<br />
|-<br />
| Det-set, full mission || HFI_SkyMap_???-ds?_2048_R2.??_full.fits || HFI_SkyMap_???-ds?_2048_R2.??_full-ringhalf-?.fits<br />
|-<br />
|Single SWB, full mission || HFI_SkyMap_???-?_2048_R2.??_full.fits || HFI_SkyMap_???-?_2048_R2.??_full-ringhalf-?.fits<br />
|}<br />
<br />
{| class="wikitable" align="center" style="text-align"left" border="1" cellpadding="15" cellspacing="20" width=1000px<br />
|+ '''LFI FITS filenames'''<br />
|- bgcolor="ffdead"<br />
! Coverage || filename || half-ring filename || Comment<br />
|-<br />
| Full channel, full mission ||LFI_SkyMap_???_1024_R2.??_full.fits ||LFI_SkyMap_???_1024_R2.??_full-ringhalf-?.fits || Available also at Nside = 2048<br />
|-<br />
| Full channel, single survey || LFI_SkyMap_???_1024_R2.??_survey-?.fits || n/a || Available also at Nside = 2048<br />
|-<br />
| Full channel, survey combination || LFI_SkyMap_???_1024_R2.??_survey-1-3-5-6-7-8.fits || n/a || n/a<br />
|-<br />
| Full channel, single year || LFI_SkyMap_???_1024_R2.??_year-?.fits || n/a || Available also at Nside = 2048<br />
|-<br />
| Full channel, year combination || LFI_SkyMap_???_1024_R2.??_year?-?.fits || n/a || n/a<br />
|-<br />
| Horn pair, full mission || LFI_SkyMap_???-??-??_1024_R2.??_full.fits || LFI_SkyMap_???_??-??_1024_R2.??_full-ringhalf-?.fits || Available also at Nside = 2048<br />
|-<br />
| Single radiometer, full mission || LFI_SkyMap_???-???_1024_R2.??_full.fits || LFI_SkyMap_???-???_1024_R2.??_full-ringhalf-?.fits || n/a<br />
|}<br />
<br />
<br />
<br />
For the benefit of users who are only looking for the frequency maps with no additional information, we also provide a file combining the 9 frequency maps as separate columns in a single extension. The 9 columns in this file contain the intensity maps ONLY and no other information (hit maps and variance maps) is provided.<br />
<br />
<!---<br />
{| class="wikitable" align="center" style="text-align:center" border="1" cellpadding="3" cellspacing="0" width=500px<br />
|+ '''FITS filenames'''<br />
|- bgcolor="ffdead"<br />
! Frequency || Full channel maps<br />
|-<br />
| '''30GHz''' || {{PLASingleFile|fileType=map|name=LFI_SkyMap_030_1024_R1.10_nominal.fits|link=LFI_SkyMap_030_1024_R1.10_nominal.fits}}<br />
|-<br />
| '''44GHz''' || {{PLASingleFile|fileType=map|name=LFI_SkyMap_044_1024_R1.10_nominal.fits|link=LFI_SkyMap_044_1024_R1.10_nominal.fits}}<br />
|-<br />
| '''70GHz''' || {{PLASingleFile|fileType=map|name=LFI_SkyMap_070_1024_R1.10_nominal.fits|link=LFI_SkyMap_070_1024_R1.10_nominal.fits}}<br />
|-<br />
| '''70GHz''' || {{PLASingleFile|fileType=map|name=LFI_SkyMap_070_2048_R1.10_nominal.fits|link=LFI_SkyMap_070_2048_R1.10_nominal.fits}}<br />
|-<br />
| '''100GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_100_2048_R1.10_nominal.fits|link=HFI_SkyMap_100_2048_R1.10_nominal.fits}}<br />
|-<br />
| '''143GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_143_2048_R1.10_nominal.fits|link=HFI_SkyMap_143_2048_R1.10_nominal.fits}}<br />
|-<br />
| '''217GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_217_2048_R1.10_nominal.fits|link=HFI_SkyMap_217_2048_R1.10_nominal.fits}}<br />
|-<br />
| '''353GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_353_2048_R1.10_nominal.fits|link=HFI_SkyMap_353_2048_R1.10_nominal.fits}}<br />
|-<br />
| '''545GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_545_2048_R1.10_nominal.fits|link=HFI_SkyMap_545_2048_R1.10_nominal.fits}}<br />
|-<br />
| '''857GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_857_2048_R1.10_nominal.fits|link=HFI_SkyMap_857_2048_R1.10_nominal.fits}}<br />
|- bgcolor="ffdead"<br />
! Frequency || Full channel, Zodi-corrected maps<br />
|-<br />
| '''100GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_100_2048_R1.10_nominal_ZodiCorrected.fits|link=HFI_SkyMap_100_2048_R1.10_nominal_ZodiCorrected.fits}} <br />
|-<br />
| '''143GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_143_2048_R1.10_nominal_ZodiCorrected.fits|link=HFI_SkyMap_143_2048_R1.10_nominal_ZodiCorrected.fits}}<br />
|-<br />
| '''217GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_217_2048_R1.10_nominal_ZodiCorrected.fits|link=HFI_SkyMap_217_2048_R1.10_nominal_ZodiCorrected.fits}}<br />
|-<br />
| '''353GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_353_2048_R1.10_nominal_ZodiCorrected.fits|link=HFI_SkyMap_353_2048_R1.10_nominal_ZodiCorrected.fits}}<br />
|-<br />
| '''545GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_545_2048_R1.10_nominal_ZodiCorrected.fits|link=HFI_SkyMap_545_2048_R1.10_nominal_ZodiCorrected.fits}}<br />
|-<br />
| '''857GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_857_2048_R1.10_nominal_ZodiCorrected.fits|link=HFI_SkyMap_857_2048_R1.10_nominal_ZodiCorrected.fits}}<br />
|- bgcolor="ffdead"<br />
! Frequency || Combined frequency maps<br />
|-<br />
| '''All''' || {{PLASingleFile|fileType=file|name=COM_MapSet_I-allFreqs_R1.10_nominal.fits|link=COM_MapSet_I-allFreqs_R1.10_nominal.fits}} <br />
|}<br />
<br />
<br />
{| class="wikitable" align="center" style="text-align:center" border="1" cellpadding="3" cellspacing="0" width=850px<br />
|+ '''FITS filenames'''<br />
|- bgcolor="ffdead"<br />
! Frequency || Survey 1 maps || Survey 2 maps<br />
|-<br />
| '''30GHz''' || {{PLASingleFile|fileType=map|name=LFI_SkyMap_030_1024_R1.10_survey_1.fits|link=LFI_SkyMap_030_1024_R1.10_survey_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=LFI_SkyMap_030_1024_R1.10_survey_2.fits|link=LFI_SkyMap_030_1024_R1.10_survey_2.fits}}<br />
|-<br />
| '''44GHz''' || {{PLASingleFile|fileType=map|name=LFI_SkyMap_044_1024_R1.10_survey_1.fits|link=LFI_SkyMap_044_1024_R1.10_survey_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=LFI_SkyMap_044_1024_R1.10_survey_2.fits|link=LFI_SkyMap_044_1024_R1.10_survey_2.fits}}<br />
|-<br />
| '''70GHz''' || {{PLASingleFile|fileType=map|name=LFI_SkyMap_070_1024_R1.10_survey_1.fits|link=LFI_SkyMap_070_1024_R1.10_survey_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=LFI_SkyMap_070_1024_R1.10_survey_2.fits|link=LFI_SkyMap_070_1024_R1.10_survey_2.fits}}<br />
|-<br />
| '''70GHz''' || {{PLASingleFile|fileType=map|name=LFI_SkyMap_070_2048_R1.10_survey_1.fits|link=LFI_SkyMap_070_2048_R1.10_survey_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=LFI_SkyMap_070_2048_R1.10_survey_2.fits|link=LFI_SkyMap_070_2048_R1.10_survey_2.fits}}<br />
|-<br />
| '''100GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_100_2048_R1.10_survey_1.fits|link=HFI_SkyMap_100_2048_R1.10_survey_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_100_2048_R1.10_survey_2.fits|link=HFI_SkyMap_100_2048_R1.10_survey_2.fits}}<br />
|-<br />
| '''143GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_143_2048_R1.10_survey_1.fits|link=HFI_SkyMap_143_2048_R1.10_survey_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_143_2048_R1.10_survey_2.fits|link=HFI_SkyMap_143_2048_R1.10_survey_2.fits}}<br />
|-<br />
| '''217GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_217_2048_R1.10_survey_1.fits|link=HFI_SkyMap_217_2048_R1.10_survey_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_217_2048_R1.10_survey_2.fits|link=HFI_SkyMap_217_2048_R1.10_survey_2.fits}}<br />
|-<br />
| '''353GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_353_2048_R1.10_survey_1.fits|link=HFI_SkyMap_353_2048_R1.10_survey_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_353_2048_R1.10_survey_2.fits|link=HFI_SkyMap_353_2048_R1.10_survey_2.fits}}<br />
|-<br />
| '''545GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_545_2048_R1.10_survey_1.fits|link=HFI_SkyMap_545_2048_R1.10_survey_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_545_2048_R1.10_survey_2.fits|link=HFI_SkyMap_545_2048_R1.10_survey_2.fits}}<br />
|-<br />
| '''857GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_857_2048_R1.10_survey_1.fits|link=HFI_SkyMap_857_2048_R1.10_survey_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_857_2048_R1.10_survey_2.fits|link=HFI_SkyMap_857_2048_R1.10_survey_2.fits}}<br />
|- bgcolor="ffdead"<br />
! Frequency || Survey 1 Zodi-corrected maps || Survey 2 Zodi-corrected maps<br />
|-<br />
| '''100GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_100_2048_R1.10_survey_1_ZodiCorrected.fits|link=HFI_SkyMap_100_2048_R1.10_survey_1_ZodiCorrected.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_100_2048_R1.10_survey_2_ZodiCorrected.fits|link=HFI_SkyMap_100_2048_R1.10_survey_2_ZodiCorrected.fits}}<br />
|-<br />
| '''143GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_143_2048_R1.10_survey_1_ZodiCorrected.fits|link=HFI_SkyMap_143_2048_R1.10_survey_1_ZodiCorrected.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_143_2048_R1.10_survey_2_ZodiCorrected.fits|link=HFI_SkyMap_143_2048_R1.10_survey_2_ZodiCorrected.fits}}<br />
|-<br />
| '''217GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_217_2048_R1.10_survey_1_ZodiCorrected.fits|link=HFI_SkyMap_217_2048_R1.10_survey_1_ZodiCorrected.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_217_2048_R1.10_survey_2_ZodiCorrected.fits|link=HFI_SkyMap_217_2048_R1.10_survey_2_ZodiCorrected.fits}}<br />
|-<br />
| '''353GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_353_2048_R1.10_survey_1_ZodiCorrected.fits|link=HFI_SkyMap_353_2048_R1.10_survey_1_ZodiCorrected.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_353_2048_R1.10_survey_2_ZodiCorrected.fits|link=HFI_SkyMap_353_2048_R1.10_survey_2_ZodiCorrected.fits}}<br />
|-<br />
| '''545GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_545_2048_R1.10_survey_1_ZodiCorrected.fits|link=HFI_SkyMap_545_2048_R1.10_survey_1_ZodiCorrected.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_545_2048_R1.10_survey_2_ZodiCorrected.fits|link=HFI_SkyMap_545_2048_R1.10_survey_2_ZodiCorrected.fits}}<br />
|-<br />
| '''857GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_857_2048_R1.10_survey_1_ZodiCorrected.fits|link=HFI_SkyMap_857_2048_R1.10_survey_1_ZodiCorrected.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_857_2048_R1.10_survey_2_ZodiCorrected.fits|link=HFI_SkyMap_857_2048_R1.10_survey_2_ZodiCorrected.fits}}<br />
|- bgcolor="ffdead"<br />
! Frequency || Half-ring 1 maps ||Half-ring 2 maps<br />
|-<br />
| '''30GHz''' || {{PLASingleFile|fileType=map|name=LFI_SkyMap_030_1024_R1.10_nominal_ringhalf_1.fits|link=LFI_SkyMap_030_1024_R1.10_nominal_ringhalf_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=LFI_SkyMap_030_1024_R1.10_nominal_ringhalf_2.fits|link=LFI_SkyMap_030_1024_R1.10_nominal_ringhalf_2.fits}}<br />
|-<br />
| '''44GHz''' || {{PLASingleFile|fileType=map|name=LFI_SkyMap_044_1024_R1.10_nominal_ringhalf_1.fits|link=LFI_SkyMap_044_1024_R1.10_nominal_ringhalf_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=LFI_SkyMap_044_1024_R1.10_nominal_ringhalf_2.fits|link=LFI_SkyMap_044_1024_R1.10_nominal_ringhalf_2.fits}}<br />
|-<br />
| '''70GHz''' || {{PLASingleFile|fileType=map|name=LFI_SkyMap_070_1024_R1.10_nominal_ringhalf_1.fits|link=LFI_SkyMap_070_1024_R1.10_nominal_ringhalf_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=LFI_SkyMap_070_1024_R1.10_nominal_ringhalf_2.fits|link=LFI_SkyMap_070_1024_R1.10_nominal_ringhalf_2.fits}}<br />
|-<br />
| '''70GHz''' || {{PLASingleFile|fileType=map|name=LFI_SkyMap_070_2048_R1.10_nominal_ringhalf_1.fits|link=LFI_SkyMap_070_2048_R1.10_nominal_ringhalf_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=LFI_SkyMap_070_2048_R1.10_nominal_ringhalf_2.fits|link=LFI_SkyMap_070_2048_R1.10_nominal_ringhalf_2.fits}}<br />
|-<br />
| '''100GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_100_2048_R1.10_nominal_ringhalf_1.fits|link=HFI_SkyMap_100_2048_R1.10_nominal_ringhalf_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_100_2048_R1.10_nominal_ringhalf_2.fits|link=HFI_SkyMap_100_2048_R1.10_nominal_ringhalf_2.fits}}<br />
|-<br />
| '''143GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_143_2048_R1.10_nominal_ringhalf_1.fits|link=HFI_SkyMap_143_2048_R1.10_nominal_ringhalf_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_143_2048_R1.10_nominal_ringhalf_2.fits|link=HFI_SkyMap_143_2048_R1.10_nominal_ringhalf_2.fits}}<br />
|-<br />
| '''217GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_217_2048_R1.10_nominal_ringhalf_1.fits|link=HFI_SkyMap_217_2048_R1.10_nominal_ringhalf_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_217_2048_R1.10_nominal_ringhalf_2.fits|link=HFI_SkyMap_217_2048_R1.10_nominal_ringhalf_2.fits}}<br />
|-<br />
| '''353GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_353_2048_R1.10_nominal_ringhalf_1.fits|link=HFI_SkyMap_353_2048_R1.10_nominal_ringhalf_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_353_2048_R1.10_nominal_ringhalf_2.fits|link=HFI_SkyMap_353_2048_R1.10_nominal_ringhalf_2.fits}}<br />
|-<br />
| '''545GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_545_2048_R1.10_nominal_ringhalf_1.fits|link=HFI_SkyMap_545_2048_R1.10_nominal_ringhalf_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_545_2048_R1.10_nominal_ringhalf_2.fits|link=HFI_SkyMap_545_2048_R1.10_nominal_ringhalf_2.fits}}<br />
|-<br />
| '''857GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_857_2048_R1.10_nominal_ringhalf_1.fits|link=HFI_SkyMap_857_2048_R1.10_nominal_ringhalf_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_857_2048_R1.10_nominal_ringhalf_2.fits|link=HFI_SkyMap_857_2048_R1.10_nominal_ringhalf_2.fits}}<br />
|}<br />
---><br />
<br />
''' FITS file structure '''<br />
<br />
The FITS files for the sky maps contain a minimal primary header with no data, and a ''BINTABLE'' extension (EXTENSION 1, EXTNAME = ''FREQ-MAP'') containing the data. The structure is shows schematically in the figure below. The ''FREQ-MAP'' extension contains a 3- or a 10-column table that contain the signal, hit-count and variance maps, all in Healpix format. The 3-column case is for intensity only maps, the 10-column case is for polarisation. The number of rows is the number of map pixels, which is Npix = 12 <math>N_{side}</math><sup>2</sup> for Healpix maps, where <math>N_{side}</math> = 1024 or 2048 for most the maps presented in this chapter.<br />
<br />
[[File:FITS_FreqMap.png | 550px | center | thumb | '''FITS file structure''']]<br />
<br />
Note that file sizes are ~0.6 GB for I-only maps and ~1.9 GB for I,Q,U maps at <math>N_{side}</math> 2048 and ~0.14 GB for I-only maps and ~0.45 GB for I,Q,U maps at <math>N_{side}</math> 1024 .<br />
<br />
Keywords indicate the coordinate system (GALACTIC), the Healpix ordering scheme (NESTED), the units (K_cmb or MJy/sr) of each column, and of course the frequency channel (FREQ). Where polarisation Q and U maps are provided, the ''COSMO'' polarisation convention (used in HEALPIX) is adopted, and it is specified in the ''POLCCONV'' keyword (see [[Sky_temperature_maps#Polarization_convention_used_in_the_Planck_project|this section]]. The COMMENT fields give a one-line summary of the product, and some other information useful for traceability within the DPCs. The original filename is also given in the ''FILENAME'' keyword. The ''BAD_DATA'' keyword gives the value used by Healpix to indicate pixels for which no signal is present (these will also have a hit-count value of 0). The main parameters are summarised below:<br />
<br />
<br />
{| border="1" cellpadding="3" cellspacing="0" align="center" style="text-align:left" width=800px<br />
|+ '''Sky map file data structure'''<br />
|- bgcolor="ffdead" <br />
!colspan="4" | 1. EXTNAME = 'FREQ-MAP' : Data columns<br />
|- bgcolor="ffdead" <br />
! Column Name || Data Type || Units || Description<br />
|-<br />
|I_STOKES || Real*4 || K_cmb or MJy/sr || The Stokes I map<br />
|-<br />
|Q_STOKES || Real*4 || K_cmb or MJy/sr || The Stokes Q map (optional)<br />
|-<br />
|U_STOKES || Real*4 || K_cmb or MJy/sr || The Stokes U map (optional)<br />
|-<br />
|HITS || Int*4 || none || The hit-count map<br />
|-<br />
|II_COV || Real*4 || K_cmb<sup>2</sup> or (MJy/sr)<sup>2</sup> || The II variance map<br />
|-<br />
|IQ_COV || Real*4 || K_cmb<sup>2</sup> or (MJy/sr)<sup>2</sup> || The IQ variance map (optional)<br />
|-<br />
|IU_COV || Real*4 || K_cmb<sup>2</sup> or (MJy/sr)<sup>2</sup> || The IQ variance map (optional)<br />
|-<br />
|QQ_COV || Real*4 || K_cmb<sup>2</sup> or (MJy/sr)<sup>2</sup> || The QQ variance map (optional)<br />
|-<br />
|QU_COV || Real*4 || K_cmb<sup>2</sup> or (MJy/sr)<sup>2</sup> || The QU variance map (optional)<br />
|-<br />
|UU_COV || Real*4 || K_cmb<sup>2</sup> or (MJy/sr)<sup>2</sup> || The UU variance map (optional)<br />
|-<br />
|- bgcolor="ffdead" <br />
! Keyword || Data Type || Value || Description<br />
|-<br />
|PIXTYPE || string || HEALPIX ||<br />
|-<br />
|COORDSYS || string || GALACTIC ||Coordinate system <br />
|-<br />
|ORDERING || string || NESTED || Healpix ordering<br />
|-<br />
|POLCCONV || String || COSMO || Polarization convention<br />
|-<br />
|NSIDE || Int || 1024 or 2048 || Healpix <math>N_{side}</math> <br />
|-<br />
|FIRSTPIX || Int*4 || 0 || First pixel number<br />
|-<br />
|LASTPIX || Int*4 || 12 <math>N_{side}</math><sup>2</sup> – 1 || Last pixel number<br />
|-<br />
|FREQ || string || nnn || The frequency channel <br />
|}<br />
<br />
<br />
The same structure applies to all ''SkyMap'' products, independent of whether they are full channel, survey of half-ring. The distinction between the types of maps is present in the FITS filename (and in the traceability comment fields).<br />
<br />
'''Polarization convention used in the Planck project'''<br />
<br />
The Planck collaboration used the COSMO convention for the polarization angle (as usually used in space based CMB missions), whereas other astronomical fields usually use the IAU convention. In the following document we report the difference between these two conventions, and the consequence if it is NOT taken into account correctly in the analysis.<br />
<br />
[[File:conventions.png|thumb|center|400px|'''Figure 1. COSMO convention (left) and IAU convention (right). The versor <math>\hat{z}</math> points outwards the pointing direction in COSMO, and inwards in IAU. The bottom panel refers to the plane tangent to the sphere.''']]<br />
<br />
Changing the orientation convention is equivalent to a transformation <math>\psi'=\pi-\psi</math> of the polarization angle (Figure 1). The consequence of this transformation is the inversion of the Stokes parameter <math>U</math>.<br />
The components of the polarization tensor in the helicity basis <math>\epsilon^{\pm}=1/\sqrt{2}(\hat{x}\pm i\hat{y})</math> are:<br />
<br />
<math><br />
(Q+iU)(\hat{n}) = \sum _{\ell m}a_{2,lm}{}_{2}Y_{\ell }^{m}(\hat{n})<br />
\\(Q-iU)(\hat{n}) = \sum _{\ell m}a_{-2,lm}{}_{2}Y_{\ell }^{m}(\hat{n})<br />
</math><br />
<br />
where <math>{}_{2}Y_{\ell }^{m}(\hat{n})</math> are the spin weighted spherical harmonic functions.<br />
The <math>E</math> and <math>B</math> modes can be defined as:<br />
<math><br />
E(\hat{n}) = \sum_{\ell m}a_{E,\ell m}Y_{\ell }^{m}(\hat{n})<br />
\\B(\hat{n}) = \sum_{\ell m}a_{B,\ell m}Y_{\ell }^{m}(\hat{n})<br />
</math><br />
<br />
where the coefficients <math>a_{E,\ell m}</math> and <math>a_{B,\ell m}</math> are derived from linear combinations of the <math>a_{2,\ell m}</math> , <math>a_{-2,\ell m}</math> defined implicitly in the first equation (<math>Q\pm iU</math>).<br />
<br />
[[File:test_gradient.jpg|thumb|center|400px|]]<br />
[[File:test_curl.jpg|thumb|center|400px|'''Figure 2. Error on Planck-LFI 70 GHz <math>EE</math> (top) and <math>BB</math> (bottom) spectra, in case of wrong choice of the coordinate system convention (IAU instead of COSMO).''']]<br />
<br />
The effect of the sign inversion of <math>U</math> on the polarization spectra is a non trivial mixing of <math>E</math> and <math>B</math> modes. <br />
<br />
An example of the typical error on <math>EE</math> and <math>BB</math> auto-spectra in case of a wrong choice of the polarization basis is shown in Figure 2.<br />
<br />
BE CAREFUL about the polarization convention you are using. If the IAU convention is used in computing the power spectra, the sign of the <math>U</math> component of the Planck maps must be inverted before computing <math>E</math> and <math>B</math> modes.<br />
<br />
''' Note on the convention used by the Planck Catalogue of Compact Sources (PCCS) '''<br />
For continuity with other compact sources catolgues, the Catalogue of Compact Sources provided by Planck follows the IAU convention, and the polarization angles are defined on an interval of [-90&deg;,90&deg;]. To switch to the COSMO convention, the polarization angles listed in the catalogue have to be shifted by 90&deg; and multiplied by -1.<br />
<br />
== References ==<br />
<References /><br />
<br />
</div><br />
</div><br />
<br />
<div class="toccolours mw-collapsible mw-collapsed" style="background-color: #EEE8AA;width:80%" ><br />
'''2013 Sky temperature maps'''<br />
<br />
<div class="mw-collapsible-content"><br />
<br />
'''General description'''<br />
<br />
<br />
Sky maps give the best estimate of the intensity of the signal from the sky after removal, as far as possible, of known systematic effects and of the dipole signals induced by the motion of the solar system in the CMB and of the Planck satellite in the solar system. Sky maps are provided for the nominal Planck mission and also, separately, for the first two single surveys, the third one being covered only for a small part during the nominal mission.The details of the start and end times of each are given in [[HFIpreprocessingstatics | this table]]. As a secondary product, maps with estimates of the Zodiacal light and Far-Side-Lobes contribution removed are also provided. <br />
<br />
For characterization purposes, are also provided maps covering the nominal survey but each one using only half of the available data. These are the ''ringhalf_{1|2}'' maps, which are built using the first and second half of the stable pointing part in each pointing period. These maps are used extensively to investigate the (high frequency) noise properties the maps themselves and of other products described elsewhere (see e.g., the [[HFI-Validation | data validation]] section).<br />
<br />
To help in further processing, there are also masks of the Galactic Plane and of point sources, each provided for several different depths.<br />
<br />
All sky maps are in Healpix format, with Nside of 2048 for HFI and of 1024 for LFI (note that the LFI 70 GHz has been delivered also at Nside of 2048 to be directly comparable with HFI maps), in Galactic coordinates, and Nested ordering. The signal is given in units of K<sub>cmb</sub> for 30-353 GHz, and of MJy/sr (for a constant $\nu F_\nu$ energy distribution ) for 545 and 857 GHz. Each sky map is packaged into a ''BINTABLE'' extension of a FITS file together with a hit-count map (or hit map, for short, giving the number of observation samples that are cumulated in a pixel, all detectors combined) and a variance map (determined from the half-ring maps), and additional information is given in the FITS file header. The structure of the FITS file is given in the [[#Format | FITS file structure]] section below.<br />
<br />
<br />
'''Types of maps '''<br />
<br />
; Full channel maps<br />
: Full channel maps are built using all the valid detectors of a frequency channel and cover the nominal mission. For HFI, the 143-8 and 545-3 bolometers are rejected entirely as they are seriously affected by RTS noise. The maps are displayed in the figures below. The range is the same from 30 - 143 GHz in order to show the CMB at the same level. At higher frequencies the range is increased in order to keep the Galactic Plane from invading the whole sky.<br />
<br />
<center><br />
<gallery style="padding:0 0 0 0;" perrow=3 widths=260px heights=160px> <br />
File: SkyMap30.png| '''Nominal mission, 30 GHz'''<br />
File: SkyMap44.png | '''Nominal mission, 44 GHz'''<br />
File: SkyMap70.png | '''Nominal mission, 70 GHz'''<br />
File: SkyMap100.png | '''Nominal mission, 100 GHz'''<br />
File: SkyMap143.png | '''Nominal mission, 143 GHz'''<br />
File: SkyMap217.png | '''Nominal mission, 217 GHz'''<br />
File: SkyMap353.png | '''Nominal mission, 353 GHz'''<br />
File: SkyMap545.png | '''Nominal mission, 545 GHz'''<br />
File: SkyMap857.png | '''Nominal mission, 857 GHz'''<br />
</gallery><br />
</center><br />
<br />
; Single survey maps <br />
: Single survey maps are built using all valid detectors of a frequency channel; they cover separately the different sky surveys. The surveys are defined as the times over which the satellite spin axis rotates but 180 degrees, which, due to the position of the detectors in the focal plane does not cover the full sky, but a fraction between ~80 and 90% depending on detector position.<br />
<br />
; Detector set or detector pairs maps<br />
: These are maps built from a subset of the detectors in a frequency channel, typically our of two PSB pairs (i.e., four poloarisation-sensitive bolometers with different orientation on the sky), for HFI in order to extract a single temperature map. While none of these maps are part of the first Planck data release, the concept of ''detset'' is used, and thus it is worth mentioning it here. In particular, information by detector set is available at the [[Frequency_maps_angular_power_spectra | sky power spectrum]] level and in the [[The RIMO | RIMO]].<br />
<br />
; Half-ring maps<br />
: Half-ring maps are built using only the first or the second half of the stable pointing period data. There are thus two half-ring maps per frequency channel named ''ringhalf_1'' and ''ringhalf_2'' respectively. These maps are built for characterization purposes in order to perform null tests. In particular, the difference between the two half-ring maps at a given frequency give a good estimate of the high frequency noise in the data (albeit biased low by ~0.5% for the HFI channels due to specifics of the TOI processing).<br />
<br />
; Masks<br />
: Masks are provided of the Galactic Plane and of the point sources. For the Galactic Plane, eight masks are given covering different fractions of the sky, and for the points sources two masks are given, at the 5 and 10 sigma level, for each Planck HFI frequency channel. These are generic masks, specific masks applicable to other products are delivered with the products themselves.<br />
<br />
''' Caveats and known issues'''<br />
<br />
The primary limitation of the HFI maps are<br />
* the absence of correction of the ADC non-linearities,<br />
* the far-side lobe contribution is not accounted for in the processing and in the calibration,<br />
* the dipole removal is based on the non-relativistic approximation which leaves a weak quadrupole component in the map.<br />
And thus the overall calibration accuracy is at the 0.2% level in 100-217 GHz channels<br />
<br />
The LFI 70 GHz maps at Nside=2048 should be considered as additional product, the default are the LFI maps at Nside=1024. No effective beam at Nside=2048 is provided, only at Nside=1024, for this reason the use of the effective beam with maps at Nside 2048 is discouraged.<br />
<br />
''' Map zero-level '''<br />
<br />
For the 100 to 857 GHz maps, the zero levels are set to their optimal levels for Galactic and CIB studies. A procedure for adjusting them to astrophysical values is given in the HFI Calibration paper {{PlanckPapers|planck2013-p03b}}.<br />
<br />
For the 30, 44 and 70 GHz, maps are corrected for zero level monopole by applying an offset correction, see LFI Calibration paper {{PlanckPapers|planck2013-p02b}} section 3.4 "Setting the zero levels in the maps". Note that the offset applied is indicated in the header as a comment keyword.<br />
<br />
''' The Zodiacal light and the Far-Side Lobes '''<br />
<br />
The figures below show the modeled Zodiacal light and Far Side Lobes projected onto the maps; they are simply the difference between the ''main product'' and the ''ZodiCorrected'' maps for the nominal mission. The units are given in the figures. The ''heat'' color table has been used in place of the standard Planck for clarity reasons. <br />
<center><br />
<gallery perrow=3 widths=260px heights=170px><br />
File: ZodiRes100.png | '''zodi/FSL rediduals - 100 GHz'''<br />
File: ZodiRes143.png | '''zodi/FSL rediduals - 143 GHz''' <br />
File: ZodiRes217.png | '''zodi/FSL rediduals - 217 GHz'''<br />
File: ZodiRes353.png | '''zodi/FSL rediduals - 353 GHz'''<br />
File: ZodiRes545.png | '''zodi/FSL rediduals - 545 GHz'''<br />
File: ZodiRes857.png | '''zodi/FSL rediduals - 857 GHz'''<br />
</gallery><br />
</center><br />
The effects of the FSLs are seen most clearly at the highest frequencies, as structures roughly symmetric about the center of the image, which corresponds to the location of the Galactic Centre, which is in turn the source of most of the radiation that is scattered into the FSLs.<br />
<br />
''' Artifacts near caustics of the scanning strategy '''<br />
<br />
The [[Survey scanning and performance|scanning strategy]] is such that regions around the Ecliptic poles are surveyed very deeply and compared to the average, and the transition from the nominal depth to the high depth, as shows on hit-count maps is very rapid, namely a few pixels, for a contrast of ~30. These transitions, or caustics in the maps, occur at different positions on the sky for different detectors, as the positions depend on their location in the focal plane of the instrument. As a result, when data from different detectors are combined to build a full channel map, the the weights of different detectors in the mix changes rapidly across the caustic, and given the remaining errors in the relative calibration of the detectors, a visible effect can be introduced in the maps, especially when the SNR is very high, i.e. at the highest frequencies and near bright regions like the Galactic Plane. Some examples are shown below.<br />
<br />
<center><br />
<gallery perrow=3 heights=260px widths=260pix ><br />
File: causta857.png | '''857 GHz intensity map around (272.5, -27)'''<br />
File: caustb857.png | '''857 GHz intensity map around (264.5, -37.5)'''<br />
File: caustc857.png | '''857 GHz intensity map around (98.5, 43)'''<br />
File: hita857.png | '''857 GHz hit count map around (272.5, -27)'''<br />
File: hitb857.png | '''857 GHz hit count map around (264.5, -37.5)'''<br />
File: hitc857.png | '''857 GHz hit count map around (98.5, 43)'''<br />
</gallery><br />
</center><br />
<br />
'''Production process'''<br />
<br />
<br />
Sky maps are produced by combining appropriately the data of all working detectors in a frequency channel over some period of the mission. They give the best estimate of the signal from the sky (unpolarised) after removal, as far as possible, of known systematic effects and of the dipole signals induced by the motion of the solar system in the CMB and of the Planck satellite in the solar system. In particular, they include the Zodiacal light emission (Zodi for short) and also the scattering from the far-side lobes of the beams (FSL). More on this below.<br />
<br />
''' HFI processing '''<br />
<br />
The inputs to the mapmaking are TOIs of signal that have been cleaned (as far as possible) of instrumental effects and calibrated in absorbed watts. While the processing involved is described in detail in the [[TOI processing|TOI processing]] section, we give a very brief summary here for convenience. That pipeline performs the following operations:<br />
<br />
; demodulation: this is performed around a variable level which is determined from the valid input data (a validity flag from a previous version of the processing is used for this purpose), and the data are converted to engineering units (V) using known conversion coefficients.<br />
; despiking: using the demodulated data converted to V (by the transfer function) the glitches are identified and fitted with templates. A glitch flag is produced that identifies the strongest part of the glitches, and a timeline of glitch tails is produced from the template fits, and subtracted from the demodulated timeline from step 1. Finally, the flagged ranges are replaced with data from an average over the pointing period (TBC)<br />
; dark template removal: the two dark bolometers are demodulated and despiked as above; the resulting timelines are then smoothed and used as an indicator of the overall temperature variations of the bolometer plate. Where the variations are consistent with each other, they are combined and removed from the bolometer signal timelines using appropriate coupling coefficients. The few percent of the data where they are not consistent are flagged on the timelines.<br />
; conversion to absorbed power: the timeline is converted to watts of absorbed power using the bolometer function. This includes a non-linearity correction; removal of the 4K cooler lines: the electromagnetic interference of the 4K cooler with the bolometer readout wires induces some sharp lines in the signal power spectra at frequencies of the 4K cooler's fundamental and its multiples, folded by the signal modulations. Fourier coefficients of the relevant lines are determined on a per-ring basis, and then removed from the data. The quality of the removal depends on the bolometer.<br />
; deconvolution by the time transfer function: this is done to correct for the non-instantaneous time response of the bolometers. The function itself is modeled using 4 parameters which are adjusted primarily on the planet data and also from comparisons of the northward and southward scans of the Galactic Plane. It is then removed using Fourier techniques, which has the side-effect of increasing the noise at high frequencies.<br />
; jump correction: removes some (relatively rare: 0.3 jumps per bolometer per pointing period, on average) jumps in the signal baseline. The jumps are detected characterized on smoothed TOIs, and corrected by adding a constant to part of the signal timeline. The origin of the jumps is not known.<br />
<br />
The results of this processing are a timeline of signal (in absorbed watts) and a ''valid data'' flag timeline for each of the 50 valid bolometers processed; these timelines contain the full sky signal, i.e., including the solar and orbital dipoles, the Zodiacal light, and contributions from the Far-Side lobes. The dipoles are necessary for the flux calibration and are removed at the mapmaking stage. The remaining two bolometers (143-8 and 535-3) show semi-random jumps in the signal level, typically jumping over 2-5 different ''pseudo-baseline'' levels, a behavior known as ''Random Telegraphic Signal'', so that these are commonly called the RTS bolometers. Finally, ring-level statistics of different types (mean, median, rms, kurtosis, etc.) are determined on a per-ring basis for all timelines, and a selection based on these statistics is used to discard anomalous rings, which are recorded in a ring-level flag for each valid bolometer timeline (see the [[TOI_processing#Discarded_rings| Discarded rings]] section). <br />
<br />
Throughout this processing, bright planets (Mars, Jupiter, Saturn, Uranus) and bright asteroids are masked in the timeline in order to avoid ringing effects in the processing. Since they move on the sky, the portion of the sky masked during one survey is observed during one, and no hole is left in the final map. In parallel, the planet data are processed in a similar way, but with different parameters for the despiking step, and without the final jump correction step. These results are processed separately to determine the beam shapes and the focal plane geometry.<br />
<br />
The pointing is determined starting from the AHF produced by MOC, which gives the direction and orientation of the LOS of a fiducial position in the focal plane at frequencies of 8Hz during stable pointing and 4 Hz during maneuvers (TBC for details, reference). This is interpolated to the times of data observation (ref to method), corrected for the wobble and other time-dependent offsets determined from the observed positions of a large number of sources around the sky, and finally converted to the LOS of each detector using the quaternions in the IMO (which are determined from observations of bright planets - see the [[Detector_pointing]] section). <br />
<br />
The mapmaking and calibration process is described in detail in the [[Map-making_LFI | Map-making]] section, where detailed references are found. In brief it consists of:<br />
<br />
; binning the TOI data onto ''rings'' : Healpix rings (HPRs) are used here, each ring containing the combined data of one pointing period. <br />
; flux calibration : at 100-353 GHz, the flux calibration factors are determined for each pointing period (or ring) from the solar-motion dipole, using the WMAP dipole as the reference, and after removal of the dipole signal induced by the motion of the Planck satellite in the solar system. This gain by ring is smoothed with a window of width 50 rings, which reveals an apparent variation of ~1-2% on a scale of 100s to 1000s of rings for the 100-217 GHz channels, and is applied. At 353GHz, where the solar motion dipole is weaker compared to the signal, no gain variation is detected (within the uncertainties), and a single fixed gain is applied to all rings. At 545 and 857 GHz the gain is determined from the observation of Uranus and Neptune (but not Jupiter which is too bright) and comparison to recent models made explicitly for this mission. A single gain is applied to all rings at these frequencies.<br />
; destriping : in order to remove low-frequency noise, an offset per ring is determined by minimizing the differences between HPRs at their crossings, and removed.<br />
; projection onto the map : the offset-corrected and flux-calibrated HPRs are projected onto Healpix maps, with the data of each bolometer weighted by a factor of 1/NET of that bolometer, and accounting for the slight different band transmission profiles of the bolometers in each band. <br />
<br />
These maps provide the main mission products. A second, reduced, set of maps, cleaned of the Zodiacal emission of the FSL leakage is also produced for the nominal mission and the two single surveys, but not for the half-rings (since the contribution would be the same for the two halves of each ring). For this purpose, the the Zodiacal emission and the FSL contamination, which are not fixed on the sky, are modeled separately at HPR-level, and subtracted from the signal HPR before projecting them onto the maps. <br />
<br />
Together with signal maps, hit count and variance maps are also produced. The hit maps give the (integer) number of valid TOI-level samples that contribute to the signal of each pixel. All valid samples are counted in the same way, i.e., there is no weighting factor applied. The variance maps project the white noise estimate, provided by the NETs, in the sky domain.<br />
<br />
''' LFI processing '''<br />
<br />
LFI maps were constructed with the Madam map-making code, version 3.7.4. The code is based on generalized destriping technique, where the correlated noise component is modeled as a sequence of constant offset, called baselines. A noise filter was used to constrain the baseline solution allowing the use of 1 second baselines.<br />
<br />
Radiometers were combined according to the horn-uniform weighting scheme to minimize systematics. The used weights are listed in [[Map-making LFI#Map-making|Map-making]]. The flagged samples were excluded from the analysis by setting their weights to $C_{w}^{-1}$ = 0. The galaxy region was masked out in the destriping phase, to reduce error arising from strong signal gradients. The polarization component was included in the analysis, although only the temperature maps are released. <br />
<br />
A detailed description of the map-making procedure is given in {{PlanckPapers|planck2013-p02}} and in section [[Map-making LFI#Map-making|Map-making]].<br />
<br />
'''Inputs'''<br />
<br />
<br />
''' HFI inputs '''<br />
<br />
* The cleaned TOIs of signal of each detector, together with their flags, produced by the [[TOI processing|TOI processing]] pipeline<br />
* The TOIs of pointing (quaternions), described in [[Detector_pointing]]<br />
* Bolometer-level characterization data, from the DPC's internal IMO (not distributed)<br />
* Planck orbit data used to compute and remove the earth dipole<br />
* WMAP solar dipole information used to calibrate the CMB channels<br />
* Planet models used to calibrate the Galactic channels.<br />
<br />
''' LFI inputs '''<br />
<br />
The Madam map-maker takes as an input:<br />
<br />
* The calibrated timelines (for details see [[TOI processing LFI|TOI Processing]])<br />
* The detector pointings (for details see [[Detector pointing|Detector pointing]])<br />
* The noise information in the form of three-parameter (white noise level ($\sigma$), slope, and knee frequency ($f_\mathrm{knee}$)) noise model (for details see [[The RIMO|RIMO]])<br />
<br />
'''Related products'''<br />
<br />
<br />
''' Masks '''<br />
<br />
Masks are provided of<br />
<br />
; the point sources<br />
: 15 masks are provided, three for the LFI (one mask for each frequency masking at the 4<math>\sigma</math> level) and 12 for the HFI (two masks for each frequency at the 5 and 10<math>\sigma</math> levels. For the HFI the masks can be used as they are, for the LFI they need to be downgraded to Nside=1024 except for the 70 GHz channel at Nside=2048 which does not need to be downgraded.<br />
<br />
; the Galactic Plane<br />
: 8 masks are provided giving 20, 40, 60, 70, 80, 90, 97, and 99% sky coverage in two different files, at Nside=2048. For the HFI they can be used as they are, for the LFI they need to be downgraded at Nside=1024 (note that if using the 70 GHZ at Nside=2048 no downgraded is needed)<br />
<br />
<br />
The masks are binary, in GALACTIC coordinates, and NESTED ordering. The table below give the filenames. <br />
<br />
<br />
{| class="wikitable" align="center" style="text-align:center" border="1" cellpadding="5" cellspacing="0" <br />
|+ '''FITS filenames for masks'''<br />
|-bgcolor="ffdead"<br />
! Frequency || LFI Point Source masks<br />
|-<br />
| '''30GHz''' || {{PLASingleFile|fileType=map|name=LFI_MASK_030-ps_2048_R1.00.fits|link=LFI_MASK_030-ps_2048_R1.00.fits}}<br />
|-<br />
| '''44GHz''' || {{PLASingleFile|fileType=map|name=LFI_MASK_044-ps_2048_R1.00.fits|link=LFI_MASK_044-ps_2048_R1.00.fits}}<br />
|-<br />
| '''70GHz''' || {{PLASingleFile|fileType=map|name=LFI_MASK_070-ps_2048_R1.00.fits|link=LFI_MASK_070-ps_2048_R1.00.fits}}<br />
|- bgcolor="ffdead"<br />
! colspan="2" | HFI Point Source masks<br />
|-<br />
| colspan="2" | {{PLASingleFile|fileType=map|name=HFI_Mask_PointSrc_2048_R1.10.fits|link=HFI_Mask_PointSrc_2048_R1.10.fits}}<br />
|- bgcolor="ffdead"<br />
! colspan="2" | Galactic Plane masks<br />
|-<br />
| colspan="2" | {{PLASingleFile|fileType=map|name=HFI_Mask_GalPlane_2048_R1.10.fits|link=HFI_Mask_GalPlane_2048_R1.10.fits}} <br />
|}<br />
<br />
<br />
The masks are shows below in a single figure. While this is quite clear for the Galactic Plane masks, it is less so for the point source masks, but it does give a clear perspective on how the latter are distributed over the sky.<br />
<br />
<center><br />
<gallery perrow=2 widths=300px heights=185px ><br />
File: HFI_GalPlaneMask.png | '''Galactic Plane masks'''<br />
File: HFI_PointSrcMask.png | '''PointSource masks'''<br />
</gallery><br />
</center><br />
<br />
''' File names '''<br />
<br />
<br />
The FITS filenames are of the form ''{H|L}FI_SkyMap_fff_nnnn_R1.nn_{coverage}_{type}.fits'', where ''fff'' are three digits to indicate the Planck frequency band, and ''nnnn'' is the Healpix Nside of the map, ''coverage'' indicates which part of the mission is covered, and the optional ''type'' indicates the subset of input data used. A full list of products, with links to them in the Archive, is given in the tables below.<br />
<br />
For the benefit of users who are only looking for the frequency maps with no additional information, we also provide a file combining the 9 frequency maps as separate columns in a single extension. The 9 columns in this file contain the intensity maps ONLY and no other information (hit maps and variance maps) is provided.<br />
<br />
{| class="wikitable" align="center" style="text-align:center" border="1" cellpadding="5" cellspacing="0" width=500px<br />
|+ '''FITS filenames'''<br />
|- bgcolor="ffdead"<br />
! Frequency || Full channel maps<br />
|-<br />
| '''30GHz''' || {{PLASingleFile|fileType=map|name=LFI_SkyMap_030_1024_R1.10_nominal.fits|link=LFI_SkyMap_030_1024_R1.10_nominal.fits}}<br />
|-<br />
| '''44GHz''' || {{PLASingleFile|fileType=map|name=LFI_SkyMap_044_1024_R1.10_nominal.fits|link=LFI_SkyMap_044_1024_R1.10_nominal.fits}}<br />
|-<br />
| '''70GHz''' || {{PLASingleFile|fileType=map|name=LFI_SkyMap_070_1024_R1.10_nominal.fits|link=LFI_SkyMap_070_1024_R1.10_nominal.fits}}<br />
|-<br />
| '''70GHz''' || {{PLASingleFile|fileType=map|name=LFI_SkyMap_070_2048_R1.10_nominal.fits|link=LFI_SkyMap_070_2048_R1.10_nominal.fits}}<br />
|-<br />
| '''100GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_100_2048_R1.10_nominal.fits|link=HFI_SkyMap_100_2048_R1.10_nominal.fits}}<br />
|-<br />
| '''143GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_143_2048_R1.10_nominal.fits|link=HFI_SkyMap_143_2048_R1.10_nominal.fits}}<br />
|-<br />
| '''217GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_217_2048_R1.10_nominal.fits|link=HFI_SkyMap_217_2048_R1.10_nominal.fits}}<br />
|-<br />
| '''353GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_353_2048_R1.10_nominal.fits|link=HFI_SkyMap_353_2048_R1.10_nominal.fits}}<br />
|-<br />
| '''545GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_545_2048_R1.10_nominal.fits|link=HFI_SkyMap_545_2048_R1.10_nominal.fits}}<br />
|-<br />
| '''857GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_857_2048_R1.10_nominal.fits|link=HFI_SkyMap_857_2048_R1.10_nominal.fits}}<br />
|- bgcolor="ffdead"<br />
! Frequency || Full channel, Zodi-corrected maps<br />
|-<br />
| '''100GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_100_2048_R1.10_nominal_ZodiCorrected.fits|link=HFI_SkyMap_100_2048_R1.10_nominal_ZodiCorrected.fits}} <br />
|-<br />
| '''143GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_143_2048_R1.10_nominal_ZodiCorrected.fits|link=HFI_SkyMap_143_2048_R1.10_nominal_ZodiCorrected.fits}}<br />
|-<br />
| '''217GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_217_2048_R1.10_nominal_ZodiCorrected.fits|link=HFI_SkyMap_217_2048_R1.10_nominal_ZodiCorrected.fits}}<br />
|-<br />
| '''353GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_353_2048_R1.10_nominal_ZodiCorrected.fits|link=HFI_SkyMap_353_2048_R1.10_nominal_ZodiCorrected.fits}}<br />
|-<br />
| '''545GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_545_2048_R1.10_nominal_ZodiCorrected.fits|link=HFI_SkyMap_545_2048_R1.10_nominal_ZodiCorrected.fits}}<br />
|-<br />
| '''857GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_857_2048_R1.10_nominal_ZodiCorrected.fits|link=HFI_SkyMap_857_2048_R1.10_nominal_ZodiCorrected.fits}}<br />
|- bgcolor="ffdead"<br />
! Frequency || Combined frequency maps<br />
|-<br />
| '''All''' || {{PLASingleFile|fileType=file|name=COM_MapSet_I-allFreqs_R1.10_nominal.fits|link=COM_MapSet_I-allFreqs_R1.10_nominal.fits}} <br />
|}<br />
<br />
<br />
{| class="wikitable" align="center" style="text-align:center" border="1" cellpadding="5" cellspacing="0" width=850px<br />
|+ '''FITS filenames'''<br />
|- bgcolor="ffdead"<br />
! Frequency || Survey 1 maps || Survey 2 maps<br />
|-<br />
| '''30GHz''' || {{PLASingleFile|fileType=map|name=LFI_SkyMap_030_1024_R1.10_survey_1.fits|link=LFI_SkyMap_030_1024_R1.10_survey_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=LFI_SkyMap_030_1024_R1.10_survey_2.fits|link=LFI_SkyMap_030_1024_R1.10_survey_2.fits}}<br />
|-<br />
| '''44GHz''' || {{PLASingleFile|fileType=map|name=LFI_SkyMap_044_1024_R1.10_survey_1.fits|link=LFI_SkyMap_044_1024_R1.10_survey_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=LFI_SkyMap_044_1024_R1.10_survey_2.fits|link=LFI_SkyMap_044_1024_R1.10_survey_2.fits}}<br />
|-<br />
| '''70GHz''' || {{PLASingleFile|fileType=map|name=LFI_SkyMap_070_1024_R1.10_survey_1.fits|link=LFI_SkyMap_070_1024_R1.10_survey_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=LFI_SkyMap_070_1024_R1.10_survey_2.fits|link=LFI_SkyMap_070_1024_R1.10_survey_2.fits}}<br />
|-<br />
| '''70GHz''' || {{PLASingleFile|fileType=map|name=LFI_SkyMap_070_2048_R1.10_survey_1.fits|link=LFI_SkyMap_070_2048_R1.10_survey_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=LFI_SkyMap_070_2048_R1.10_survey_2.fits|link=LFI_SkyMap_070_2048_R1.10_survey_2.fits}}<br />
|-<br />
| '''100GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_100_2048_R1.10_survey_1.fits|link=HFI_SkyMap_100_2048_R1.10_survey_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_100_2048_R1.10_survey_2.fits|link=HFI_SkyMap_100_2048_R1.10_survey_2.fits}}<br />
|-<br />
| '''143GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_143_2048_R1.10_survey_1.fits|link=HFI_SkyMap_143_2048_R1.10_survey_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_143_2048_R1.10_survey_2.fits|link=HFI_SkyMap_143_2048_R1.10_survey_2.fits}}<br />
|-<br />
| '''217GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_217_2048_R1.10_survey_1.fits|link=HFI_SkyMap_217_2048_R1.10_survey_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_217_2048_R1.10_survey_2.fits|link=HFI_SkyMap_217_2048_R1.10_survey_2.fits}}<br />
|-<br />
| '''353GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_353_2048_R1.10_survey_1.fits|link=HFI_SkyMap_353_2048_R1.10_survey_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_353_2048_R1.10_survey_2.fits|link=HFI_SkyMap_353_2048_R1.10_survey_2.fits}}<br />
|-<br />
| '''545GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_545_2048_R1.10_survey_1.fits|link=HFI_SkyMap_545_2048_R1.10_survey_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_545_2048_R1.10_survey_2.fits|link=HFI_SkyMap_545_2048_R1.10_survey_2.fits}}<br />
|-<br />
| '''857GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_857_2048_R1.10_survey_1.fits|link=HFI_SkyMap_857_2048_R1.10_survey_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_857_2048_R1.10_survey_2.fits|link=HFI_SkyMap_857_2048_R1.10_survey_2.fits}}<br />
|- bgcolor="ffdead"<br />
! Frequency || Survey 1 Zodi-corrected maps || Survey 2 Zodi-corrected maps<br />
|-<br />
| '''100GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_100_2048_R1.10_survey_1_ZodiCorrected.fits|link=HFI_SkyMap_100_2048_R1.10_survey_1_ZodiCorrected.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_100_2048_R1.10_survey_2_ZodiCorrected.fits|link=HFI_SkyMap_100_2048_R1.10_survey_2_ZodiCorrected.fits}}<br />
|-<br />
| '''143GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_143_2048_R1.10_survey_1_ZodiCorrected.fits|link=HFI_SkyMap_143_2048_R1.10_survey_1_ZodiCorrected.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_143_2048_R1.10_survey_2_ZodiCorrected.fits|link=HFI_SkyMap_143_2048_R1.10_survey_2_ZodiCorrected.fits}}<br />
|-<br />
| '''217GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_217_2048_R1.10_survey_1_ZodiCorrected.fits|link=HFI_SkyMap_217_2048_R1.10_survey_1_ZodiCorrected.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_217_2048_R1.10_survey_2_ZodiCorrected.fits|link=HFI_SkyMap_217_2048_R1.10_survey_2_ZodiCorrected.fits}}<br />
|-<br />
| '''353GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_353_2048_R1.10_survey_1_ZodiCorrected.fits|link=HFI_SkyMap_353_2048_R1.10_survey_1_ZodiCorrected.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_353_2048_R1.10_survey_2_ZodiCorrected.fits|link=HFI_SkyMap_353_2048_R1.10_survey_2_ZodiCorrected.fits}}<br />
|-<br />
| '''545GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_545_2048_R1.10_survey_1_ZodiCorrected.fits|link=HFI_SkyMap_545_2048_R1.10_survey_1_ZodiCorrected.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_545_2048_R1.10_survey_2_ZodiCorrected.fits|link=HFI_SkyMap_545_2048_R1.10_survey_2_ZodiCorrected.fits}}<br />
|-<br />
| '''857GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_857_2048_R1.10_survey_1_ZodiCorrected.fits|link=HFI_SkyMap_857_2048_R1.10_survey_1_ZodiCorrected.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_857_2048_R1.10_survey_2_ZodiCorrected.fits|link=HFI_SkyMap_857_2048_R1.10_survey_2_ZodiCorrected.fits}}<br />
|- bgcolor="ffdead"<br />
! Frequency || Half-ring 1 maps ||Half-ring 2 maps<br />
|-<br />
| '''30GHz''' || {{PLASingleFile|fileType=map|name=LFI_SkyMap_030_1024_R1.10_nominal_ringhalf_1.fits|link=LFI_SkyMap_030_1024_R1.10_nominal_ringhalf_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=LFI_SkyMap_030_1024_R1.10_nominal_ringhalf_2.fits|link=LFI_SkyMap_030_1024_R1.10_nominal_ringhalf_2.fits}}<br />
|-<br />
| '''44GHz''' || {{PLASingleFile|fileType=map|name=LFI_SkyMap_044_1024_R1.10_nominal_ringhalf_1.fits|link=LFI_SkyMap_044_1024_R1.10_nominal_ringhalf_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=LFI_SkyMap_044_1024_R1.10_nominal_ringhalf_2.fits|link=LFI_SkyMap_044_1024_R1.10_nominal_ringhalf_2.fits}}<br />
|-<br />
| '''70GHz''' || {{PLASingleFile|fileType=map|name=LFI_SkyMap_070_1024_R1.10_nominal_ringhalf_1.fits|link=LFI_SkyMap_070_1024_R1.10_nominal_ringhalf_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=LFI_SkyMap_070_1024_R1.10_nominal_ringhalf_2.fits|link=LFI_SkyMap_070_1024_R1.10_nominal_ringhalf_2.fits}}<br />
|-<br />
| '''70GHz''' || {{PLASingleFile|fileType=map|name=LFI_SkyMap_070_2048_R1.10_nominal_ringhalf_1.fits|link=LFI_SkyMap_070_2048_R1.10_nominal_ringhalf_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=LFI_SkyMap_070_2048_R1.10_nominal_ringhalf_2.fits|link=LFI_SkyMap_070_2048_R1.10_nominal_ringhalf_2.fits}}<br />
|-<br />
| '''100GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_100_2048_R1.10_nominal_ringhalf_1.fits|link=HFI_SkyMap_100_2048_R1.10_nominal_ringhalf_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_100_2048_R1.10_nominal_ringhalf_2.fits|link=HFI_SkyMap_100_2048_R1.10_nominal_ringhalf_2.fits}}<br />
|-<br />
| '''143GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_143_2048_R1.10_nominal_ringhalf_1.fits|link=HFI_SkyMap_143_2048_R1.10_nominal_ringhalf_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_143_2048_R1.10_nominal_ringhalf_2.fits|link=HFI_SkyMap_143_2048_R1.10_nominal_ringhalf_2.fits}}<br />
|-<br />
| '''217GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_217_2048_R1.10_nominal_ringhalf_1.fits|link=HFI_SkyMap_217_2048_R1.10_nominal_ringhalf_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_217_2048_R1.10_nominal_ringhalf_2.fits|link=HFI_SkyMap_217_2048_R1.10_nominal_ringhalf_2.fits}}<br />
|-<br />
| '''353GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_353_2048_R1.10_nominal_ringhalf_1.fits|link=HFI_SkyMap_353_2048_R1.10_nominal_ringhalf_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_353_2048_R1.10_nominal_ringhalf_2.fits|link=HFI_SkyMap_353_2048_R1.10_nominal_ringhalf_2.fits}}<br />
|-<br />
| '''545GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_545_2048_R1.10_nominal_ringhalf_1.fits|link=HFI_SkyMap_545_2048_R1.10_nominal_ringhalf_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_545_2048_R1.10_nominal_ringhalf_2.fits|link=HFI_SkyMap_545_2048_R1.10_nominal_ringhalf_2.fits}}<br />
|-<br />
| '''857GHz''' || {{PLASingleFile|fileType=map|name=HFI_SkyMap_857_2048_R1.10_nominal_ringhalf_1.fits|link=HFI_SkyMap_857_2048_R1.10_nominal_ringhalf_1.fits}} ||<br />
{{PLASingleFile|fileType=map|name=HFI_SkyMap_857_2048_R1.10_nominal_ringhalf_2.fits|link=HFI_SkyMap_857_2048_R1.10_nominal_ringhalf_2.fits}}<br />
|}<br />
<br />
''' FITS file structure '''<br />
<br />
<br />
[[File:FITS_FreqMap.png | 500px | right | thumb | '''FITS file structure''']]<br />
<br />
The FITS files for the sky maps contain a minimal primary header with no data, and a ''BINTABLE'' extension (EXTENSION 1, EXTNAME = ''FREQ-MAP'') containing the data. The structure is shows schematically in the figure at right. <br />
<br />
The ''FREQ-MAP'' extension contains is a 3-column table that contain the signal, hit-count and variance maps, all in Healpix format, in columns 1, 2, and 3, respectively. The number of rows is 50331648 for HFI and LFI 70 GHz at Nside=2048 and 12582912 for LFI maps at Nside=1024 (N.B: Npix = 12 Nside^2). The three columns are ''I_STOKES'' for the intensity (or temperature) signal, ''HIT'' for the hit-count and ''II_COV'' for the variance. The exact order of the columns in the figure is indicative only, and the details can be found in the keywords. <br />
<br />
Keywords indicate the coordinate system (GALACTIC), the Healpix ordering scheme (NESTED), the units (K_cmb or MJy/sr) of each column, and of course the frequency channel (FREQ). The COMMENT fields give a one-line summary of the product, and some other information useful for traceability within the DPCs. The original filename is also given in the ''FILENAME'' keyword as are the datasum and the md5 checksum for the extension. The ''BAD_DATA'' keyword gives the value used by Healpix to indicate pixels for which no signal is present (these will also have a hit-count value of 0). The COMMENT fields give further information including some traceability data for the DPC's. The main parameters are summarised below:<br />
<br />
<br />
{| border="1" cellpadding="3" cellspacing="0" align="center" style="text-align:left" width=800px<br />
|+ '''Sky map file data structure'''<br />
|- bgcolor="ffdead" <br />
!colspan="4" | 1. EXTNAME = 'FREQ-MAP' : Data columns<br />
|- bgcolor="ffdead" <br />
! Column Name || Data Type || Units || Description<br />
|-<br />
|I_STOKES || Real*4 || K_cmb or MJy/sr || The signal map<br />
|-<br />
|HITS || Int*4 || none || The hit-count map<br />
|-<br />
|II_COV || Real*4 || K_cmb<sup>2</sup> or (MJy/sr)<sup>2</sup> || The variance map<br />
|- bgcolor="ffdead" <br />
! Keyword || Data Type || Value || Description<br />
|-<br />
|PIXTYPE || string || HEALPIX ||<br />
|-<br />
|COORDSYS || string || GALACTIC ||Coordinate system <br />
|-<br />
|ORDERING || string || NESTED || Healpix ordering<br />
|-<br />
|NSIDE || Int || 1024 or 2048 || Healpix Nside <br />
|-<br />
|FIRSTPIX || Int*4 || 0 || First pixel number<br />
|-<br />
|LASTPIX || Int*4 || 12582911 or 50331647 || Last pixel number<br />
|-<br />
|FREQ || string || nnn || The frequency channel <br />
|}<br />
<br />
<br />
The same structure applies to all ''SkyMap'' products, independent of whether they are full channel, survey of half-ring. The distinction between the types of maps is present in the FITS filename (and in the traceability comment fields).<br />
<br />
''' References'''<br />
<br />
<References /><br />
<br />
<br />
</div><br />
</div><br />
<br />
<br />
<br />
[[Category:Mission products|002]]</div>Azaccheihttps://wiki.cosmos.esa.int/planck-legacy-archive/index.php?title=Timelines&diff=14095Timelines2018-07-06T12:45:52Z<p>Azacchei: /* LFI processing */</p>
<hr />
<div>{{DISPLAYTITLE: Timelines}}<br />
==General description==<br />
<br />
The timelines, or TOIs for "time-ordered information," are vectors of signal or of pointing or of some other quantity, giving the value of that quantity as a function of time during the mission. For LFI, refer to {{PlanckPapers|planck2014-a03}}, and for HFI, to {{PlanckPapers|planck2014-a08}}.<br />
<br />
The TOIs described here are sampled regularly at the (instrument-dependent) detector sampling frequency and span the full science mission. They thus consist of a large amount of data. This section is concerned with the signal TOIs and their associated pointing TOIs. For selected detectors the DPCs provide a single timeline of cleaned and calibrated signal and three timelines of coordinates, corresponding to the two angular coordinates and one orientation angle. <br />
<br />
Obviously these vectors are very long (about 1.38&times;10<sup>10</sup> samples for HFI, from 2.5&times;10<sup>6</sup> to 5.5&times;10<sup>6</sup> for LFI) and thus need to be split into multiple files for export. Here the data are split by operational day (OD) as follows:<br />
* HFI has 12 files per OD, one for pointing and one for signal for each channel, covering ODs 91 to 974, all sampled at <i>F</i><sub>samp</sub> = 180.3737 Hz;<br />
* LFI has six files per OD, three each for signal and pointing, since the sampling frequency is channel dependent, and covering ODs 91 to 1543, sampled at <i>F</i><sub>samp</sub> = 32.5079, <i>F</i><sub>samp</sub> = 46.5455, and <i>F</i><sub>samp</sub> = 78.7692 Hz.<br />
<br />
The signal timelines are encoded as single-precision real values, but the pointing vectors had to be encoded as double-precision reals to maintain the required accuracy. The result is that the total volume of the full dataset is approximately 30 TB. All files also contain the OBT.<br />
<br />
The signal timelines have been cleaned of all known instrumental systematic effects, they have been calibrated in flux, and the solar and Earth motion dipole signals have been removed. But they have not been cleaned of the low-frequency, "1/<i>f</i>" noise that needs to be removed via a destriping tool. The methods consists of removing offsets or "baselines" determined by minimizing the differences in the signals at points on the sky where they intersect. For HFI an offset per ring is determined; for LFI the the baseline is computed every 0.246, 0.988, and 1.000 seconds for the 30, 44, and 70 GHz channels, respectively and maintain the same structure of the signal timelines.<br />
<br />
In the case of HFI these offsets are determined using the full mission and all the valid detectors per channel, and they are then used for all the maps produced, i.e., for those maps using any fraction of the mission (year, survey) or any subset of the detectors (single detector, detector set), and it has been shown that using offsets determined from a limited part of the mission and/or a subset of the detectors yields maps that are less consistent than otherwise. <br />
<br />
In the case of LFI these offsets are determined using the full mission and all the valid detectors per channel; those values have been used for the production of the full mission period maps. Note that baseline used for shorter period maps are determined on those data periods to avoid noise cross-correlation effects and those are not delivered.<br />
<br />
The offsets are delivered separately, as described below.<br />
<br />
Furthermore, for HFI and LFI, there are three sets of offsets produced: the primary set using the full rings; and the secondary ones using the first and second half rings, only. The differences between the primary and secondary sets are fairly minor, but they are necessary to include to reconstruct the maps as they were built by the HFI-DPC and LFI-DPC. In particular the offsets are useful for users wishing to build a map of a small area of the sky.<br />
<br />
The HFI delivers its offsets in a ROI, or "ring-ordered Information" file. That file contains a table of <i>N</i><sub>rings</sub> = 26766 rows by <i>N</i><sub>bolometers</sub> in which each cell contains a 3-element vector containing the full-ring, first half-ring, and second half-ring offsets. The indices of the signal TOI delimiting the rings are given in a second ROI file with the same <i>N</i><sub>rings</sub> rows containing global parameters.<br />
<br />
The LFI delivers its offsets in a TOI format, the structure is <i>exactly</i> the same as that used by the science timelines. The user can simply subtract one-by-one the offset timelines from the science timelines and then generate a map using the result.<br />
In the case of the half-ring baselines, a vector has been added in the OBT extension; this vector contains "1" or "2," depending which half ring it should be applied to.<br />
<br />
===HFI indexing===<br />
<br />
Each FITS file contains keywords giving the first and last index of the section of the full TOI contained in the file. These indices are those of the internal DPC representation; they begin at 0, corresponding to the switch-on of the instrument, and run to some very large number (about 25 billion for HFI) representing the full mission. Only the <i>science</i> part of the mission is exported, which is about 60% of the total for HFI. Left out are the early mission phase (cool-down and validation phases) and the warm phase of HFI, during which LFI continued to collect data. The HFI keywords also indicate which rings are included in each OD, but note that normally an OD does not begin at the same time (with the same index) as a ring. <br />
<br />
Note that for historical reasons, the OD definitions of the two DPCs differ; for LFI they occur at the transition between pointing periods, whereas for HFI they do not. However, this has no significance for the user, since this splitting is somewhat arbitrary anyway, and what counts is the full vector once it is rebuilt in the user's own work space.<br />
<br />
HFI timelines at the DPC are indexed from 0 to 25&times;10<sup>9</sup>, which correspond to instrument switch-on and switch-off, respectively. Of these the indices 1.4&times;10<sup>9</sup> to 151.5&times;10<sup>9</sup> correspond to the science mission and are exported and delivered. Each file contains a keyword giving the first and last index of the data in that file, and EndIndex(OD)+1 = BeginIndex (OD+1). The ROI "Global" file gives the Begin/End Indices of each Ring, or Pointing Period, and can be used to destripe the signal TOIs with the offsets provided in the "Destriping-Offsets" ROI file.<br />
<br />
==Production process==<br />
<br />
=== HFI processing ===<br />
<br />
The input TOIs are in ADUs, representing the voltage signal at the end of the electronics (see [[HFI_detection_chain | Detection chain]] for details). The processing applied to remove instrumental effects and to calibrate them is described in detail in the [[TOI processing | HFI TOI processing]] section, and in {{PlanckPapers|planck2014-a08}} we give a very brief summary here for convenience. This pipeline performs the following operations.<br />
<br />
; ADC correction: This corrects for the uneven size of the ADC bins (see [[ADC correction]]).<br />
; Demodulation: This is performed around a variable level, which is determined from the valid input data (using a validity flag from a previous version of the processing), and the data are converted to engineering units (V) using known conversion coefficients.<br />
; Despiking: The redundancy within a ring is used to determine where glitches occur. Once identified, the glitches are fitted with templates. A glitch flag is produced that identifies the strongest part of the glitches, and a timeline of glitch tails. produced from the template fits, is subtracted from the demodulated timeline. Finally, the flagged regions are replaced with data from an average over the pointing period in order to not leave holes in the timeline that would perturb the usage of Fourier methods on them<br />
; Dark template removal: The two dark bolometers are demodulated and despiked as above; the resulting timelines are then smoothed and used as an indicator of the overall temperature variations of the bolometer plate. Where the variations are consistent with each other, they are combined and removed from the bolometer signal timelines using appropriate coupling coefficients. The few percent of the data where they are not consistent are flagged as not valid on the timelines.<br />
; Conversion to absorbed power: The timeline is converted to watts of absorbed power using the bolometer function. This includes a nonlinearity correction and removal of the 4-K cooler lines (i.e., the electromagnetic interference of the 4-K cooler with the bolometer readout wires, which induces some sharp lines in the signal power spectra at frequencies of the 4-K cooler's fundamental and its multiples, folded by the signal modulations). Fourier coefficients of the relevant lines are determined on a per-ring basis, and then removed from the data. The quality of the removal depends on the bolometer.<br />
; Deconvolution by the time transfer function: This is done to correct for the non-instantaneous time response of the bolometers. The function itself is modeled using up to eight time constants, which are adjusted primarily on planet data and also from comparisons of the northward and southward scans of the Galactic Plane. It is then removed using Fourier techniques.<br />
; Jump correction: This corrects some rare jumps in the signal baseline (there are on average around 0.3 jumps per bolometer per pointing period). The jumps are detected and characterized on smoothed TOIs, and corrected by adding a constant to part of the signal timeline. The origin of the jumps is not known.<br />
<br />
The results of this set of processing steps are a timeline of signal (in absorbed watts) and a "valid data" flag timeline for each of the 50 valid bolometers that are processed, out of the 52 HFI bolometers; these timelines contain the full-sky signal, i.e., including the solar and orbital dipoles, the Zodiacal light, and contributions from the far sidelobes. The dipoles are necessary for the flux calibration and are removed at the mapmaking stage. The remaining two bolometers (143-8 and 545-3) show semi-random jumps in the signal level, typically jumping over 2 to 5 different "pseudo-baseline" levels, a behaviour known as "random telegraphic signal" (RTS), so that these are commonly called the RTS bolometers. Finally, ring-level statistics of different types (mean, median, rms, kurtosis, etc.) are determined on a per-ring basis for all timelines, and a selection based on these statistics is used to discard anomalous rings, which are recorded in a ring-level flag for each valid bolometer timeline (see the [[TOI_processing#Discarded_rings | Discarded rings]] section). <br />
<br />
Throughout this processing, some planet signals are masked in the timeline in order to avoid ringing effects in the processing. This concerns only Jupiter at 100 and 143 GHz, Jupiter and Saturn at 217 GHz, and Jupiter, Saturn, and Mars at 353, 545, and 857 GHz (thanks to various improvements in the despiking and in the transfer functions it is no longer necessary to flag these three planets in the CMB channels, as was done in the 2013 release). Since they move on the sky, the portion of the sky masked during one survey is observed during another one, and no hole is left in the final map. In parallel, the planet data are processed in a similar way, but with different parameters for the despiking step. These results are processed separately to determine the beam shapes and the focal plane geometry.<br />
<br />
Next, the TOIs are calibrated in astrophysical units using the results of the calibration pipeline (see the [[Map-making | Map-making and calibration]] section) and the best estimates of the zero-point offsets (a constant level for each bolometer). These values are given in the RIMO. Also, the solar and Earth-motion dipole signals are computed and removed. <br />
<br />
These TOIs are accompanied by several flags that are described below. The most important one is the "Total" flag, which identifies all the samples that were discarded by the DPC mapmaking, as described in [[TOI processing | HFI TOI processing]]. This flag includes the portion beyond 72 min for the rings that are longer; this is not used for science analysis because of the slight drift of the satellite pointing direction (spin axis) during these long acquisition periods.<br />
<br />
At this point the TOIs still contain the low frequency (1/<i>f</i>) noise, which should be removed before projection onto a map. That cleaning step is called "destriping" or "baseline removal". The HFI-DPC does its destriping at ring-level, meaning that a constant is added to the signal of each ring in order to minimize the difference at the ring crossings, where the signal should be the same for all detectors (with the necessary precautions as described in [[Map-making | Map-making and calibration]] section); should the user want to use the DPC's offsets, they are provided separately (see [[Timelines#ROI_files | ROI files]] below). Maps produced from these TOIs, and after subtraction of the DPC's destriping offsets, are not identical to the maps that are delivered. This is discussed in Section A.2 of {{PlanckPapers|planck2014-a09}}.<br />
<br />
As indicated above, the brightest planets are masked in the TOI in order to avoid ringing problems. For users specifically wanting to study these planets, we provide separate timelines covering just the planet transits. These timelines also include transits of Uranus and Neptune, which are not masked in the regular TOIs. They are produced with less agressive deglitching options in order to work on the rapidly changing baselines. These are the data used the reconstruction of the focal plane geometry and also for the determination of the scanning beams.<br />
<br />
The table below lists the 16 transits, giving for each the begin/end ring number and the begin/end OD in which that ring is found. Note that transit 15 is split into two parts because some tests were done during the transit. The last row is a region processed in the same manner but without a planet transit, which is included for comparison. <br />
<br />
{| border="1" cellpadding="3" cellspacing="0" align="center" style="text-align:left" width=700px<br />
|+ '''Planet transits'''<br />
|- bgcolor="ffdead" <br />
! Number || Beg Ring || End Ring || Beg OD || End OD || Comment<br />
|-<br />
| 1 || 2700 || 3211 || 160 || 176 || Jupiter, Mars, Neptune<br />
|-<br />
| 2 || 3892 || 4099 || 203 || 212 || Uranus<br />
|-<br />
| 3 || 4575 || 4775 || 233 || 240 || Saturn<br />
|-<br />
| 4 || 7900 || 8150 || 330 || 337 || Mars<br />
|-<br />
| 5 || 8979 || 9188 || 367 || 376 || Neptune<br />
|-<br />
| 6 || 9550 || 9750 || 392 || 402 || Saturn<br />
|-<br />
| 7 || 9940 || 10300 || 411 || 425 || Jupiter, Uranus<br />
|-<br />
| 8 || 14018 || 14227 || 537 || 544 || Neptune<br />
|-<br />
| 9 || 14820 || 15190 || 567 || 583 || Jupiter, Uranus<br />
|-<br />
| 10 || 15925 || 16275 || 612 || 624 || Saturn<br />
|-<br />
| 11 || 20016 || 20225 || 734 || 743 || Neptune<br />
|-<br />
| 12 || 20900 || 21650 || 775 || 804 || Saturn, Uranus<br />
|-<br />
| 13 || 21780 || 22150 || 808 || 818 || Jupiter<br />
|-<br />
| 14 || 24992 || 25202 || 916 || 921 || Neptune<br />
|-<br />
| 15a || 25830 || 25849 || 937 || 938 || Mars, Uranus<br />
|-<br />
| 15b || 25864 || 26225 || 947 || 957 || Mars, Uranus<br />
|-<br />
| 16 || 26650 || 27005 || 968 || 974 || Jupiter<br />
|-<br />
| 17 || 12000 || 12150 || 479 || 483 || background<br />
|}<br />
<br />
<br />
The pointing (see common [[Detector_pointing | Detector Pointing]] section for details) is determined from the AHF produced by the MOC, which gives the direction and orientation of the LOS of a fiducial position in the focal plane at frequencies of 8Hz during stable pointing and 4Hz during manoeuvres. This is interpolated to the timestamps of data samples, corrected for the wobble and other time-dependent offsets determined from the observed positions of a large number of sources around the sky, and finally converted to the LOS of each detector using the quaternions in the IMO. These pointing data are valid for both the regular and the planet TOIs.<br />
<br />
=== LFI processing ===<br />
The input TOIs are in ADUs, representing the voltage signal at the output of the electronics (see [[LFI design, qualification, and performance#Radiometer Chain Assembly, RCA, | Radiometer Chain Assembly (RCA)]] for details). The processing applied to remove instrumental effects and to calibrate them is described in detail in the [[TOI processing | LFI TOI processing]] section, in {{PlanckPapers|planck2014-a03||Planck-2015-A03}} and in {{PlanckPapers|planck2016-l02}}; here we give a very brief summary for convenience. That pipeline performs the following operations.<br />
; ADC correction: Due to ADC nonlinearity under certain condition, this instrumental effect is removed by applying well know templates directly to the diode signal.<br />
; Electronics spikes: This is caused by the interaction between the electronics clock and the scientific data lines. The signal is detected in all the LFI radiometer time-domain outputs as a 1-s square wave with a rising edge near 0.5s and a falling edge near 0.75s, synchronous with the onboard time signal. In the frequency domain it appears as a spike signal at multiples of 1Hz. The 44-GHz channels are the only LFI outputs significantly affected by this effect. Consequently the spike signal is removed from the data only in these channels.<br />
; Demodulation: Each LFI diode switches at 4096Hz between the sky and the 4-K reference load. The data acquired in this way are dominated by 1/<i>f</i> noise that is highly correlated between the two streams; differencing those streams results in a strong reduction of 1/<i>f</i> noise. The procedure applied is described in [[TOI processing | LFI TOI processing]], taking into account that the gain modulation factor <i>R</i> was computed on timestreams with the Galaxy and point sources masked to avoid strong sky signals.<br />
; Diode combination: Two detector diodes provide the output for each LFI receiver channel. To minimize the impact of imperfect isolation of the data stream of each diode, we perform a weighted average of the time-ordered data from the two diodes of each receiver. The procedure applied is detailed in [[TOI processing | LFI TOI processing]]; and the weights used are kept fixed for the entire mission.<br />
; Scientific calibration: This step calibrates the timelines to physical units K<sub>CMB</sub>, fitting the total CMB dipole convolved with the 4&pi; beam representation, without taking into account the signature due to Galactic stray light.<br />
; Gain regularization: The calibration constants computed using the model of the dipole signal suffer from large uncertainties when the Planck spacecraft is badly aligned with the dipole axis. To reduce the noise, we apply an adaptive smoothing algorithm, which is also designed to preserve the discontinuities caused by abrupt changes in the working configuration of the radiometers (e.g., sudden temperature changes in the focal plane).<br />
; Removal of solar and orbital dipole signal: The combined solar and orbital dipole is convolved with the 4&pi; beam representation of each radiometer and then removed from its timeline.<br />
; Removal of Galactic stray light: The light incident on the focal plane without reflecting on the primary mirror (stray light) is a major source of systematic effects, especially when the Galactic plane intersects the direction of the main spillover. This effect is corrected by removing the estimated straylight signal from the timelines. This signal is computed as the convolution of Galaxy simulation with the beam sidelobes (see details in [[TOI processing | LFI TOI processing]]).<br />
<br />
After these processing steps the timelines are used for the production of the maps.<br />
<br />
The pointing (see common [[Detector_pointing | Detector Pointing]] section for details) is determined from the AHF produced by the MOC, which gives the direction and orientation of the LOS of a fiducial position in the focal plane at frequencies of 8Hz during stable pointing and 4Hz during manoeuvres. This is interpolated to the timestamps of data samples, corrected for the wobble and other time-dependent offsets determined from the observed positions of a large number of sources around the sky, as well as temperature sensors, and finally converted to the LOS of each detector.<br />
<br />
==File Names==<br />
<br />
The file names are of the form<br />
<br />
''{H,L}FI_TOI_{fff}-{SCI,PTG,TAI,OFF}_Rn.nn_ODxxxx.fits'',<br />
<br />
where<br />
* ''fff'' denotes the frequency,<br />
* SCI denote signal TOIs,<br />
* PTG denote pointing TOIs,<br />
* TAI denotes the OBT-MJD correlation TOI,<br />
* OFF denotes the baseline TOI,<br />
* Rn.nn is the version, and<br />
* ODxxxx indicates the OD.<br />
<br />
Regarding the HFI TOIs for the 100 to 217GHz channels, the R2.00, made public in Jan 2015, contained only the unpolarized bolometer timelines, while R2.02, made public in July 2015, contains all bolometers.<br />
<br />
The HFI planet timelines are named<br />
<br />
''{H,L}FI_TOI_{fff}-SCI-planets_R2.nn_ODxxxx.fits''<br />
<br />
and are provided for all 50 valid bolometers, i.e., SWBs and PSBs.<br />
<br />
==FITS file structure==<br />
<br />
All FITS files begin with a primary extension containing no data and a minimal header, which is followed by one or more ''BINTABLE'' extensions containing data, and with a description of the data in the header keywords. In what follows we will usually ignore the primary extension, and count only the extensions containing data.<br />
<br />
===TOI files===<br />
<br />
The signal FITS files contain <i>N+1</i> , "BINTABLE", data extensions, where <i>N</i> is the number of detectors in that frequency channel. The first extension contains the OBT and its flags, called the "global" flags since they apply to all detectors, which is followed by one extension for each detector, containing the signal and its "local" flag. The flags columns are written as "byte" in which each of the 8 bits (maximum) encodes one flag timeline. The meaning of each bit is given in the header comments and is subject to change. For the global flag they include the following list.<br />
<br />
* For HFI:<br />
** unstable pointing, where 1 = pointing is not stable (e.g., during repointing manoeuvres);<br />
** dark correlation, where 1 = darks are uncorrelated and data are flagged;<br />
** first/Second half ring, which samples are in which half (only covers the stable pointing part of the ring);<br />
** HCM, whether in HCM mode (unstable pointing);<br />
** and more (see extension header for details).<br />
<br />
* For LFI:<br />
** bit 0, unstable pointing, where 1 = pointing is not stable;<br />
** bit 1, time correlation quality, where 1 = outside specification;<br />
** bit 2, special observation, where 1 = special observation, such as a deep scan.<br />
<br />
For the local flag they include the following list.<br />
<br />
* For HFI:<br />
** total flag, being a combination of the various flags that is the one finally used in the mapmaking (all samples with "total flag" different from zero should not be used);<br />
** data not valid, e.g., glitched samples;<br />
** despike common (for PSBs only), corresponding to a glitch on the current or the other of a PSB pair;<br />
** strong signal, i.e., on the Galactic plane;<br />
** strong source, i.e., on a point source;<br />
** and more (see extension header for details).<br />
<br />
* For LFI:<br />
** bit 0, data not valid, where 1 = science sample not valid;<br />
** bit 2: planet crossing, where 1 = science sample containing planet;<br />
** bit 3: moving objects, where 1 = minor Solar System object (not yet used);<br />
** bit 4: gap, where 1 = this sample was artificially included due to a gap in the data.<br />
<br />
For HFI the header extension gives more details on the flags and the meaning of "1" and "0".<br />
<br />
{| border="1" cellpadding="3" cellspacing="0" align="center" style="text-align:left" width=800px<br />
|+ '''TOI file data structure'''<br />
<br />
|- bgcolor="ffdead" <br />
!colspan="5" | 1. EXTNAME = "OBT" : Data columns<br />
|- bgcolor="ffdead" <br />
! Column name || Data type || Units || Description || Comment<br />
|-<br />
|OBT || Double || 2<sup>-16</sup> sec || Onboard time ||<br />
|-<br />
|FLAG || Byte || None || Various bit-level flags ||<br />
<br />
|- bgcolor="ffdead" <br />
! Keyword || Data Type || Value || Description || Comment<br />
|-<br />
|OD || Int || || OD covered (as in filename) ||<br />
|-<br />
|BEGIDX || Int || || First sample index of given OD || Only HFI<br />
|-<br />
|ENDIDX || Int || || Last sample index of given OD || Only HFI<br />
|-<br />
|BEGRING || Int || || First ring in given OD || Only HFI<br />
|-<br />
|ENDRING || Int || || Last ring in given OD || Only HFI<br />
|-<br />
|TIMEZERO || String || 1958-01-01z00:00 || Origin of OBT || Only HFI<br />
|-<br />
|TIMEZERO || Float || 106744000000000. || Origin of OBT || Only LFI<br />
<br />
|- bgcolor="ffdead" <br />
!colspan="5" | n. EXTNAME = ''DETNAME'' : Data columns<br />
<br />
|- bgcolor="ffdead" <br />
! Column name || Data type || Units || Description || Comment<br />
|-<br />
|SIGNAL || Real*4 || K<sub>cmb</sub> or MJy.sr<sup>-1</sup> || Value of signal || Comment<br />
|-<br />
|FLAG || Byte || None || Various bit-level flags ||<br />
|- bgcolor="ffdead" <br />
<br />
! Keyword || Data type || Value || Description || Comment<br />
|-<br />
|UNIT || String || || Units of signal || Only HFI, LFI always K<sub>cmb</sub><br />
|-<br />
|DESTRIPE || 1/0 || || Whether timeline is destriped || Only HFI<br />
|-<br />
|OD || Int || || OD covered (as in filename) ||<br />
|-<br />
|BEGIDX || Int || || First sample index of given OD || Only HFI<br />
|-<br />
|ENDIDX || Int || || Last sample index of given OD || Only HFI<br />
|-<br />
|BEGRING || Int || || First ring in given OD || Only HFI<br />
|-<br />
|ENDRING || Int || || Last ring in given OD || Only HFI<br />
|}<br />
<br />
The HFI Planet files have the same structure, but the local flags contain a single "Data not valid" flag. Also, the first and last ODs of each transit are usually not complete, since they contain only the rings that are included in the transit observations. <br />
<br />
The pointing files have a similar structure, except that ''DETNAME'' extensions contain three columns of Real*8 variables with the &phi;, &theta;, and &psi; Galactic spherical coordinates of each sample in radians, as shown in the table below. There is no local flag for the coordinates.<br />
<br />
{| border="1" cellpadding="3" cellspacing="0" align="center" style="text-align:left" width=800px<br />
|+ '''Pointing TOI file DETNAME extension structure'''<br />
<br />
|- bgcolor="ffdead" <br />
!colspan="4" | n. EXTNAME = ''DETNAME'' : Data columns<br />
<br />
|- bgcolor="ffdead" <br />
! Column name || Data type || Units || Description<br />
|-<br />
|PHI || Real*8 || Radian || Longitude<br />
|-<br />
|THETA || Real*8 || Radian || Colatitude<br />
|-<br />
|PSI || Real*8 || Radian || Roll angle<br />
|}<br />
<br />
===HFI ROI files===<br />
<br />
The files provided by HFI are<br />
* ''HFI_ROI_GlobalParams_RelNum_full.fits'',<br />
* ''HFI_ROI_DestripeOffsets_RelNum_full.fits'',<br />
which are described below.<br />
<br />
;Global parameters: This ROI file contains a single "BINTABLE" extension with three columns that give, for each ring, the index number of the first sample, the ESA pointing ID of the ring, and the ring start time. All three are encoded as Int*8, and the time is given in units of 2<sup>-16</sup> sec from "TIMEZERO", 1958-01-01z00:00, as in the TOI files. Rings are numbered from 240 to 27005, as given in the "BEGRING" and "ENDRING" keywords.<br />
<br />
; Destriping offsets: This ROI file contains a single "BINTABLE" extension with 3 columns that give, for each ring, the offsets to subtract from each bolometer signal timeline or vector. There are three offsets available for each bolometer (full-ring, first half-ring, and second half-ring), for building the full-ring or the two half-ring maps, respectively. The offsets must be subtracted from Index(<i>N</i>) to Index(<i>N+1</i>)-1 of the corresponding signal timeline, where <i>N</i> is the ring number, and the indices are given in the "global" parameters file. The offsets are given in the same units as the signal vectors, that is K<sub>cmb</sub> for the 100- to 353-GHz channels, and MJy.sr<sup>-1</sup> for the 545- and 857-GHz channels. All values are encoded as Real*4. The rings for which the offsets are set to 0.000 are [[TOI_processing#Discarded_rings | "badrings" ]] which are rejected in the mapmaking process. These rings are also flagged by the "TotalFlag", as are the portions of rings longer than about 72.5 min, where the drift in the satellite's spin axis becomes important.<br />
<br />
===TAI TOI files===<br />
<br />
The TAI TOI files contain one extension with two columns, the first is the OBT value (exactly the same as reported in the SCI TOI), the second is the corresponding modified Julian day. Note that leap seconds were not added.<br />
<br />
{| border="1" cellpadding="3" cellspacing="0" align="center" style="text-align:left" width=800px<br />
|+ '''Time TAI TOI file data structure'''<br />
<br />
|- bgcolor="ffdead" <br />
!colspan="5" | 1. EXTNAME = "OBT-MJD" : Data columns<br />
|- bgcolor="ffdead" <br />
! Column name || Data type || Units || Description || Comment<br />
|-<br />
|OBT || Int*8 || 2<sup>-16</sup> sec || Onboard time ||<br />
|-<br />
|MJD || Real*8 || day || Modified Julian day ||<br />
|}<br />
<br />
===LFI OFF TOI files===<br />
The OFF (baseline) TOI files adopt the same file structure as the Science TOI files. Note that in case of OFF timelines related to the half-ring, an additional column is included in the OBT extension to define for each sample if it belongs to half-ring 1 or half-ring 2.<br />
<br />
===LFI HouseKeeping files===<br />
House keeping timelines are:<br />
* LFI_TOI_DAE-FAST-HK_R2.nn_ODxxxx.fits;<br />
* LFI_TOI_DAE-SlowConfiguration-HK_R2.nn_ODxxxx.fits;<br />
* LFI_TOI_DAE-SlowCurrent-HK_R2.nn_ODxxxx.fits;<br />
* LFI_TOI_DAE-SlowPhaseSwitch-HK_R2.nn_ODxxxx.fits;<br />
* LFI_TOI_DAE-SlowVoltage-HK_R2.nn_ODxxxx.fits;<br />
* LFI_TOI_REBA-HK_R2.nn_ODxxxx.fits;<br />
* SCS_TOI_EssentialASW-HK_R2.nn_ODxxxx.fits;<br />
* SCS_TOI_NonEssentialASW-HK_R2.nn_ODxxxx.fits.<br />
<br />
Each file contains two extensions, the first is the OBT (values are sampled every 1 or 10 seconds), while the second contains a variable number of columns equivalent to twice the number of Housekeeping timelines stored. Each Housekeeping datum is accompanied by its flag (normally "0" means that the value was considered invalid or out of limits). The Housekeeping names are the ones defined in the LFI Instrument Operation Manual.<br />
<br />
== References ==<br />
<br />
<References /><br />
<br />
[[Category:Mission products|001]]</div>Azaccheihttps://wiki.cosmos.esa.int/planck-legacy-archive/index.php?title=Timelines&diff=14094Timelines2018-07-06T12:43:31Z<p>Azacchei: /* File Names */</p>
<hr />
<div>{{DISPLAYTITLE: Timelines}}<br />
==General description==<br />
<br />
The timelines, or TOIs for "time-ordered information," are vectors of signal or of pointing or of some other quantity, giving the value of that quantity as a function of time during the mission. For LFI, refer to {{PlanckPapers|planck2014-a03}}, and for HFI, to {{PlanckPapers|planck2014-a08}}.<br />
<br />
The TOIs described here are sampled regularly at the (instrument-dependent) detector sampling frequency and span the full science mission. They thus consist of a large amount of data. This section is concerned with the signal TOIs and their associated pointing TOIs. For selected detectors the DPCs provide a single timeline of cleaned and calibrated signal and three timelines of coordinates, corresponding to the two angular coordinates and one orientation angle. <br />
<br />
Obviously these vectors are very long (about 1.38&times;10<sup>10</sup> samples for HFI, from 2.5&times;10<sup>6</sup> to 5.5&times;10<sup>6</sup> for LFI) and thus need to be split into multiple files for export. Here the data are split by operational day (OD) as follows:<br />
* HFI has 12 files per OD, one for pointing and one for signal for each channel, covering ODs 91 to 974, all sampled at <i>F</i><sub>samp</sub> = 180.3737 Hz;<br />
* LFI has six files per OD, three each for signal and pointing, since the sampling frequency is channel dependent, and covering ODs 91 to 1543, sampled at <i>F</i><sub>samp</sub> = 32.5079, <i>F</i><sub>samp</sub> = 46.5455, and <i>F</i><sub>samp</sub> = 78.7692 Hz.<br />
<br />
The signal timelines are encoded as single-precision real values, but the pointing vectors had to be encoded as double-precision reals to maintain the required accuracy. The result is that the total volume of the full dataset is approximately 30 TB. All files also contain the OBT.<br />
<br />
The signal timelines have been cleaned of all known instrumental systematic effects, they have been calibrated in flux, and the solar and Earth motion dipole signals have been removed. But they have not been cleaned of the low-frequency, "1/<i>f</i>" noise that needs to be removed via a destriping tool. The methods consists of removing offsets or "baselines" determined by minimizing the differences in the signals at points on the sky where they intersect. For HFI an offset per ring is determined; for LFI the the baseline is computed every 0.246, 0.988, and 1.000 seconds for the 30, 44, and 70 GHz channels, respectively and maintain the same structure of the signal timelines.<br />
<br />
In the case of HFI these offsets are determined using the full mission and all the valid detectors per channel, and they are then used for all the maps produced, i.e., for those maps using any fraction of the mission (year, survey) or any subset of the detectors (single detector, detector set), and it has been shown that using offsets determined from a limited part of the mission and/or a subset of the detectors yields maps that are less consistent than otherwise. <br />
<br />
In the case of LFI these offsets are determined using the full mission and all the valid detectors per channel; those values have been used for the production of the full mission period maps. Note that baseline used for shorter period maps are determined on those data periods to avoid noise cross-correlation effects and those are not delivered.<br />
<br />
The offsets are delivered separately, as described below.<br />
<br />
Furthermore, for HFI and LFI, there are three sets of offsets produced: the primary set using the full rings; and the secondary ones using the first and second half rings, only. The differences between the primary and secondary sets are fairly minor, but they are necessary to include to reconstruct the maps as they were built by the HFI-DPC and LFI-DPC. In particular the offsets are useful for users wishing to build a map of a small area of the sky.<br />
<br />
The HFI delivers its offsets in a ROI, or "ring-ordered Information" file. That file contains a table of <i>N</i><sub>rings</sub> = 26766 rows by <i>N</i><sub>bolometers</sub> in which each cell contains a 3-element vector containing the full-ring, first half-ring, and second half-ring offsets. The indices of the signal TOI delimiting the rings are given in a second ROI file with the same <i>N</i><sub>rings</sub> rows containing global parameters.<br />
<br />
The LFI delivers its offsets in a TOI format, the structure is <i>exactly</i> the same as that used by the science timelines. The user can simply subtract one-by-one the offset timelines from the science timelines and then generate a map using the result.<br />
In the case of the half-ring baselines, a vector has been added in the OBT extension; this vector contains "1" or "2," depending which half ring it should be applied to.<br />
<br />
===HFI indexing===<br />
<br />
Each FITS file contains keywords giving the first and last index of the section of the full TOI contained in the file. These indices are those of the internal DPC representation; they begin at 0, corresponding to the switch-on of the instrument, and run to some very large number (about 25 billion for HFI) representing the full mission. Only the <i>science</i> part of the mission is exported, which is about 60% of the total for HFI. Left out are the early mission phase (cool-down and validation phases) and the warm phase of HFI, during which LFI continued to collect data. The HFI keywords also indicate which rings are included in each OD, but note that normally an OD does not begin at the same time (with the same index) as a ring. <br />
<br />
Note that for historical reasons, the OD definitions of the two DPCs differ; for LFI they occur at the transition between pointing periods, whereas for HFI they do not. However, this has no significance for the user, since this splitting is somewhat arbitrary anyway, and what counts is the full vector once it is rebuilt in the user's own work space.<br />
<br />
HFI timelines at the DPC are indexed from 0 to 25&times;10<sup>9</sup>, which correspond to instrument switch-on and switch-off, respectively. Of these the indices 1.4&times;10<sup>9</sup> to 151.5&times;10<sup>9</sup> correspond to the science mission and are exported and delivered. Each file contains a keyword giving the first and last index of the data in that file, and EndIndex(OD)+1 = BeginIndex (OD+1). The ROI "Global" file gives the Begin/End Indices of each Ring, or Pointing Period, and can be used to destripe the signal TOIs with the offsets provided in the "Destriping-Offsets" ROI file.<br />
<br />
==Production process==<br />
<br />
=== HFI processing ===<br />
<br />
The input TOIs are in ADUs, representing the voltage signal at the end of the electronics (see [[HFI_detection_chain | Detection chain]] for details). The processing applied to remove instrumental effects and to calibrate them is described in detail in the [[TOI processing | HFI TOI processing]] section, and in {{PlanckPapers|planck2014-a08}} we give a very brief summary here for convenience. This pipeline performs the following operations.<br />
<br />
; ADC correction: This corrects for the uneven size of the ADC bins (see [[ADC correction]]).<br />
; Demodulation: This is performed around a variable level, which is determined from the valid input data (using a validity flag from a previous version of the processing), and the data are converted to engineering units (V) using known conversion coefficients.<br />
; Despiking: The redundancy within a ring is used to determine where glitches occur. Once identified, the glitches are fitted with templates. A glitch flag is produced that identifies the strongest part of the glitches, and a timeline of glitch tails. produced from the template fits, is subtracted from the demodulated timeline. Finally, the flagged regions are replaced with data from an average over the pointing period in order to not leave holes in the timeline that would perturb the usage of Fourier methods on them<br />
; Dark template removal: The two dark bolometers are demodulated and despiked as above; the resulting timelines are then smoothed and used as an indicator of the overall temperature variations of the bolometer plate. Where the variations are consistent with each other, they are combined and removed from the bolometer signal timelines using appropriate coupling coefficients. The few percent of the data where they are not consistent are flagged as not valid on the timelines.<br />
; Conversion to absorbed power: The timeline is converted to watts of absorbed power using the bolometer function. This includes a nonlinearity correction and removal of the 4-K cooler lines (i.e., the electromagnetic interference of the 4-K cooler with the bolometer readout wires, which induces some sharp lines in the signal power spectra at frequencies of the 4-K cooler's fundamental and its multiples, folded by the signal modulations). Fourier coefficients of the relevant lines are determined on a per-ring basis, and then removed from the data. The quality of the removal depends on the bolometer.<br />
; Deconvolution by the time transfer function: This is done to correct for the non-instantaneous time response of the bolometers. The function itself is modeled using up to eight time constants, which are adjusted primarily on planet data and also from comparisons of the northward and southward scans of the Galactic Plane. It is then removed using Fourier techniques.<br />
; Jump correction: This corrects some rare jumps in the signal baseline (there are on average around 0.3 jumps per bolometer per pointing period). The jumps are detected and characterized on smoothed TOIs, and corrected by adding a constant to part of the signal timeline. The origin of the jumps is not known.<br />
<br />
The results of this set of processing steps are a timeline of signal (in absorbed watts) and a "valid data" flag timeline for each of the 50 valid bolometers that are processed, out of the 52 HFI bolometers; these timelines contain the full-sky signal, i.e., including the solar and orbital dipoles, the Zodiacal light, and contributions from the far sidelobes. The dipoles are necessary for the flux calibration and are removed at the mapmaking stage. The remaining two bolometers (143-8 and 545-3) show semi-random jumps in the signal level, typically jumping over 2 to 5 different "pseudo-baseline" levels, a behaviour known as "random telegraphic signal" (RTS), so that these are commonly called the RTS bolometers. Finally, ring-level statistics of different types (mean, median, rms, kurtosis, etc.) are determined on a per-ring basis for all timelines, and a selection based on these statistics is used to discard anomalous rings, which are recorded in a ring-level flag for each valid bolometer timeline (see the [[TOI_processing#Discarded_rings | Discarded rings]] section). <br />
<br />
Throughout this processing, some planet signals are masked in the timeline in order to avoid ringing effects in the processing. This concerns only Jupiter at 100 and 143 GHz, Jupiter and Saturn at 217 GHz, and Jupiter, Saturn, and Mars at 353, 545, and 857 GHz (thanks to various improvements in the despiking and in the transfer functions it is no longer necessary to flag these three planets in the CMB channels, as was done in the 2013 release). Since they move on the sky, the portion of the sky masked during one survey is observed during another one, and no hole is left in the final map. In parallel, the planet data are processed in a similar way, but with different parameters for the despiking step. These results are processed separately to determine the beam shapes and the focal plane geometry.<br />
<br />
Next, the TOIs are calibrated in astrophysical units using the results of the calibration pipeline (see the [[Map-making | Map-making and calibration]] section) and the best estimates of the zero-point offsets (a constant level for each bolometer). These values are given in the RIMO. Also, the solar and Earth-motion dipole signals are computed and removed. <br />
<br />
These TOIs are accompanied by several flags that are described below. The most important one is the "Total" flag, which identifies all the samples that were discarded by the DPC mapmaking, as described in [[TOI processing | HFI TOI processing]]. This flag includes the portion beyond 72 min for the rings that are longer; this is not used for science analysis because of the slight drift of the satellite pointing direction (spin axis) during these long acquisition periods.<br />
<br />
At this point the TOIs still contain the low frequency (1/<i>f</i>) noise, which should be removed before projection onto a map. That cleaning step is called "destriping" or "baseline removal". The HFI-DPC does its destriping at ring-level, meaning that a constant is added to the signal of each ring in order to minimize the difference at the ring crossings, where the signal should be the same for all detectors (with the necessary precautions as described in [[Map-making | Map-making and calibration]] section); should the user want to use the DPC's offsets, they are provided separately (see [[Timelines#ROI_files | ROI files]] below). Maps produced from these TOIs, and after subtraction of the DPC's destriping offsets, are not identical to the maps that are delivered. This is discussed in Section A.2 of {{PlanckPapers|planck2014-a09}}.<br />
<br />
As indicated above, the brightest planets are masked in the TOI in order to avoid ringing problems. For users specifically wanting to study these planets, we provide separate timelines covering just the planet transits. These timelines also include transits of Uranus and Neptune, which are not masked in the regular TOIs. They are produced with less agressive deglitching options in order to work on the rapidly changing baselines. These are the data used the reconstruction of the focal plane geometry and also for the determination of the scanning beams.<br />
<br />
The table below lists the 16 transits, giving for each the begin/end ring number and the begin/end OD in which that ring is found. Note that transit 15 is split into two parts because some tests were done during the transit. The last row is a region processed in the same manner but without a planet transit, which is included for comparison. <br />
<br />
{| border="1" cellpadding="3" cellspacing="0" align="center" style="text-align:left" width=700px<br />
|+ '''Planet transits'''<br />
|- bgcolor="ffdead" <br />
! Number || Beg Ring || End Ring || Beg OD || End OD || Comment<br />
|-<br />
| 1 || 2700 || 3211 || 160 || 176 || Jupiter, Mars, Neptune<br />
|-<br />
| 2 || 3892 || 4099 || 203 || 212 || Uranus<br />
|-<br />
| 3 || 4575 || 4775 || 233 || 240 || Saturn<br />
|-<br />
| 4 || 7900 || 8150 || 330 || 337 || Mars<br />
|-<br />
| 5 || 8979 || 9188 || 367 || 376 || Neptune<br />
|-<br />
| 6 || 9550 || 9750 || 392 || 402 || Saturn<br />
|-<br />
| 7 || 9940 || 10300 || 411 || 425 || Jupiter, Uranus<br />
|-<br />
| 8 || 14018 || 14227 || 537 || 544 || Neptune<br />
|-<br />
| 9 || 14820 || 15190 || 567 || 583 || Jupiter, Uranus<br />
|-<br />
| 10 || 15925 || 16275 || 612 || 624 || Saturn<br />
|-<br />
| 11 || 20016 || 20225 || 734 || 743 || Neptune<br />
|-<br />
| 12 || 20900 || 21650 || 775 || 804 || Saturn, Uranus<br />
|-<br />
| 13 || 21780 || 22150 || 808 || 818 || Jupiter<br />
|-<br />
| 14 || 24992 || 25202 || 916 || 921 || Neptune<br />
|-<br />
| 15a || 25830 || 25849 || 937 || 938 || Mars, Uranus<br />
|-<br />
| 15b || 25864 || 26225 || 947 || 957 || Mars, Uranus<br />
|-<br />
| 16 || 26650 || 27005 || 968 || 974 || Jupiter<br />
|-<br />
| 17 || 12000 || 12150 || 479 || 483 || background<br />
|}<br />
<br />
<br />
The pointing (see common [[Detector_pointing | Detector Pointing]] section for details) is determined from the AHF produced by the MOC, which gives the direction and orientation of the LOS of a fiducial position in the focal plane at frequencies of 8Hz during stable pointing and 4Hz during manoeuvres. This is interpolated to the timestamps of data samples, corrected for the wobble and other time-dependent offsets determined from the observed positions of a large number of sources around the sky, and finally converted to the LOS of each detector using the quaternions in the IMO. These pointing data are valid for both the regular and the planet TOIs.<br />
<br />
=== LFI processing ===<br />
The input TOIs are in ADUs, representing the voltage signal at the output of the electronics (see [[LFI design, qualification, and performance#Radiometer Chain Assembly, RCA, | Radiometer Chain Assembly (RCA)]] for details). The processing applied to remove instrumental effects and to calibrate them is described in detail in the [[TOI processing | LFI TOI processing]] section, and in {{PlanckPapers|planck2014-a03||Planck-2015-A03}}; here we give a very brief summary for convenience. That pipeline performs the following operations.<br />
; ADC correction: Due to ADC nonlinearity under certain condition, this instrumental effect is removed by applying well know templates directly to the diode signal.<br />
; Electronics spikes: This is caused by the interaction between the electronics clock and the scientific data lines. The signal is detected in all the LFI radiometer time-domain outputs as a 1-s square wave with a rising edge near 0.5s and a falling edge near 0.75s, synchronous with the onboard time signal. In the frequency domain it appears as a spike signal at multiples of 1Hz. The 44-GHz channels are the only LFI outputs significantly affected by this effect. Consequently the spike signal is removed from the data only in these channels.<br />
; Demodulation: Each LFI diode switches at 4096Hz between the sky and the 4-K reference load. The data acquired in this way are dominated by 1/<i>f</i> noise that is highly correlated between the two streams; differencing those streams results in a strong reduction of 1/<i>f</i> noise. The procedure applied is described in [[TOI processing | LFI TOI processing]], taking into account that the gain modulation factor <i>R</i> was computed on timestreams with the Galaxy and point sources masked to avoid strong sky signals.<br />
; Diode combination: Two detector diodes provide the output for each LFI receiver channel. To minimize the impact of imperfect isolation of the data stream of each diode, we perform a weighted average of the time-ordered data from the two diodes of each receiver. The procedure applied is detailed in [[TOI processing | LFI TOI processing]]; and the weights used are kept fixed for the entire mission.<br />
; Scientific calibration: This step calibrates the timelines to physical units K<sub>CMB</sub>, fitting the total CMB dipole convolved with the 4&pi; beam representation, without taking into account the signature due to Galactic stray light.<br />
; Gain regularization: The calibration constants computed using the model of the dipole signal suffer from large uncertainties when the Planck spacecraft is badly aligned with the dipole axis. To reduce the noise, we apply an adaptive smoothing algorithm, which is also designed to preserve the discontinuities caused by abrupt changes in the working configuration of the radiometers (e.g., sudden temperature changes in the focal plane).<br />
; Removal of solar and orbital dipole signal: The combined solar and orbital dipole is convolved with the 4&pi; beam representation of each radiometer and then removed from its timeline.<br />
; Removal of Galactic stray light: The light incident on the focal plane without reflecting on the primary mirror (stray light) is a major source of systematic effects, especially when the Galactic plane intersects the direction of the main spillover. This effect is corrected by removing the estimated straylight signal from the timelines. This signal is computed as the convolution of Galaxy simulation with the beam sidelobes (see details in [[TOI processing | LFI TOI processing]]).<br />
<br />
After these processing steps the timelines are used for the production of the maps.<br />
<br />
The pointing (see common [[Detector_pointing | Detector Pointing]] section for details) is determined from the AHF produced by the MOC, which gives the direction and orientation of the LOS of a fiducial position in the focal plane at frequencies of 8Hz during stable pointing and 4Hz during manoeuvres. This is interpolated to the timestamps of data samples, corrected for the wobble and other time-dependent offsets determined from the observed positions of a large number of sources around the sky, as well as temperature sensors, and finally converted to the LOS of each detector.<br />
<br />
==File Names==<br />
<br />
The file names are of the form<br />
<br />
''{H,L}FI_TOI_{fff}-{SCI,PTG,TAI,OFF}_Rn.nn_ODxxxx.fits'',<br />
<br />
where<br />
* ''fff'' denotes the frequency,<br />
* SCI denote signal TOIs,<br />
* PTG denote pointing TOIs,<br />
* TAI denotes the OBT-MJD correlation TOI,<br />
* OFF denotes the baseline TOI,<br />
* Rn.nn is the version, and<br />
* ODxxxx indicates the OD.<br />
<br />
Regarding the HFI TOIs for the 100 to 217GHz channels, the R2.00, made public in Jan 2015, contained only the unpolarized bolometer timelines, while R2.02, made public in July 2015, contains all bolometers.<br />
<br />
The HFI planet timelines are named<br />
<br />
''{H,L}FI_TOI_{fff}-SCI-planets_R2.nn_ODxxxx.fits''<br />
<br />
and are provided for all 50 valid bolometers, i.e., SWBs and PSBs.<br />
<br />
==FITS file structure==<br />
<br />
All FITS files begin with a primary extension containing no data and a minimal header, which is followed by one or more ''BINTABLE'' extensions containing data, and with a description of the data in the header keywords. In what follows we will usually ignore the primary extension, and count only the extensions containing data.<br />
<br />
===TOI files===<br />
<br />
The signal FITS files contain <i>N+1</i> , "BINTABLE", data extensions, where <i>N</i> is the number of detectors in that frequency channel. The first extension contains the OBT and its flags, called the "global" flags since they apply to all detectors, which is followed by one extension for each detector, containing the signal and its "local" flag. The flags columns are written as "byte" in which each of the 8 bits (maximum) encodes one flag timeline. The meaning of each bit is given in the header comments and is subject to change. For the global flag they include the following list.<br />
<br />
* For HFI:<br />
** unstable pointing, where 1 = pointing is not stable (e.g., during repointing manoeuvres);<br />
** dark correlation, where 1 = darks are uncorrelated and data are flagged;<br />
** first/Second half ring, which samples are in which half (only covers the stable pointing part of the ring);<br />
** HCM, whether in HCM mode (unstable pointing);<br />
** and more (see extension header for details).<br />
<br />
* For LFI:<br />
** bit 0, unstable pointing, where 1 = pointing is not stable;<br />
** bit 1, time correlation quality, where 1 = outside specification;<br />
** bit 2, special observation, where 1 = special observation, such as a deep scan.<br />
<br />
For the local flag they include the following list.<br />
<br />
* For HFI:<br />
** total flag, being a combination of the various flags that is the one finally used in the mapmaking (all samples with "total flag" different from zero should not be used);<br />
** data not valid, e.g., glitched samples;<br />
** despike common (for PSBs only), corresponding to a glitch on the current or the other of a PSB pair;<br />
** strong signal, i.e., on the Galactic plane;<br />
** strong source, i.e., on a point source;<br />
** and more (see extension header for details).<br />
<br />
* For LFI:<br />
** bit 0, data not valid, where 1 = science sample not valid;<br />
** bit 2: planet crossing, where 1 = science sample containing planet;<br />
** bit 3: moving objects, where 1 = minor Solar System object (not yet used);<br />
** bit 4: gap, where 1 = this sample was artificially included due to a gap in the data.<br />
<br />
For HFI the header extension gives more details on the flags and the meaning of "1" and "0".<br />
<br />
{| border="1" cellpadding="3" cellspacing="0" align="center" style="text-align:left" width=800px<br />
|+ '''TOI file data structure'''<br />
<br />
|- bgcolor="ffdead" <br />
!colspan="5" | 1. EXTNAME = "OBT" : Data columns<br />
|- bgcolor="ffdead" <br />
! Column name || Data type || Units || Description || Comment<br />
|-<br />
|OBT || Double || 2<sup>-16</sup> sec || Onboard time ||<br />
|-<br />
|FLAG || Byte || None || Various bit-level flags ||<br />
<br />
|- bgcolor="ffdead" <br />
! Keyword || Data Type || Value || Description || Comment<br />
|-<br />
|OD || Int || || OD covered (as in filename) ||<br />
|-<br />
|BEGIDX || Int || || First sample index of given OD || Only HFI<br />
|-<br />
|ENDIDX || Int || || Last sample index of given OD || Only HFI<br />
|-<br />
|BEGRING || Int || || First ring in given OD || Only HFI<br />
|-<br />
|ENDRING || Int || || Last ring in given OD || Only HFI<br />
|-<br />
|TIMEZERO || String || 1958-01-01z00:00 || Origin of OBT || Only HFI<br />
|-<br />
|TIMEZERO || Float || 106744000000000. || Origin of OBT || Only LFI<br />
<br />
|- bgcolor="ffdead" <br />
!colspan="5" | n. EXTNAME = ''DETNAME'' : Data columns<br />
<br />
|- bgcolor="ffdead" <br />
! Column name || Data type || Units || Description || Comment<br />
|-<br />
|SIGNAL || Real*4 || K<sub>cmb</sub> or MJy.sr<sup>-1</sup> || Value of signal || Comment<br />
|-<br />
|FLAG || Byte || None || Various bit-level flags ||<br />
|- bgcolor="ffdead" <br />
<br />
! Keyword || Data type || Value || Description || Comment<br />
|-<br />
|UNIT || String || || Units of signal || Only HFI, LFI always K<sub>cmb</sub><br />
|-<br />
|DESTRIPE || 1/0 || || Whether timeline is destriped || Only HFI<br />
|-<br />
|OD || Int || || OD covered (as in filename) ||<br />
|-<br />
|BEGIDX || Int || || First sample index of given OD || Only HFI<br />
|-<br />
|ENDIDX || Int || || Last sample index of given OD || Only HFI<br />
|-<br />
|BEGRING || Int || || First ring in given OD || Only HFI<br />
|-<br />
|ENDRING || Int || || Last ring in given OD || Only HFI<br />
|}<br />
<br />
The HFI Planet files have the same structure, but the local flags contain a single "Data not valid" flag. Also, the first and last ODs of each transit are usually not complete, since they contain only the rings that are included in the transit observations. <br />
<br />
The pointing files have a similar structure, except that ''DETNAME'' extensions contain three columns of Real*8 variables with the &phi;, &theta;, and &psi; Galactic spherical coordinates of each sample in radians, as shown in the table below. There is no local flag for the coordinates.<br />
<br />
{| border="1" cellpadding="3" cellspacing="0" align="center" style="text-align:left" width=800px<br />
|+ '''Pointing TOI file DETNAME extension structure'''<br />
<br />
|- bgcolor="ffdead" <br />
!colspan="4" | n. EXTNAME = ''DETNAME'' : Data columns<br />
<br />
|- bgcolor="ffdead" <br />
! Column name || Data type || Units || Description<br />
|-<br />
|PHI || Real*8 || Radian || Longitude<br />
|-<br />
|THETA || Real*8 || Radian || Colatitude<br />
|-<br />
|PSI || Real*8 || Radian || Roll angle<br />
|}<br />
<br />
===HFI ROI files===<br />
<br />
The files provided by HFI are<br />
* ''HFI_ROI_GlobalParams_RelNum_full.fits'',<br />
* ''HFI_ROI_DestripeOffsets_RelNum_full.fits'',<br />
which are described below.<br />
<br />
;Global parameters: This ROI file contains a single "BINTABLE" extension with three columns that give, for each ring, the index number of the first sample, the ESA pointing ID of the ring, and the ring start time. All three are encoded as Int*8, and the time is given in units of 2<sup>-16</sup> sec from "TIMEZERO", 1958-01-01z00:00, as in the TOI files. Rings are numbered from 240 to 27005, as given in the "BEGRING" and "ENDRING" keywords.<br />
<br />
; Destriping offsets: This ROI file contains a single "BINTABLE" extension with 3 columns that give, for each ring, the offsets to subtract from each bolometer signal timeline or vector. There are three offsets available for each bolometer (full-ring, first half-ring, and second half-ring), for building the full-ring or the two half-ring maps, respectively. The offsets must be subtracted from Index(<i>N</i>) to Index(<i>N+1</i>)-1 of the corresponding signal timeline, where <i>N</i> is the ring number, and the indices are given in the "global" parameters file. The offsets are given in the same units as the signal vectors, that is K<sub>cmb</sub> for the 100- to 353-GHz channels, and MJy.sr<sup>-1</sup> for the 545- and 857-GHz channels. All values are encoded as Real*4. The rings for which the offsets are set to 0.000 are [[TOI_processing#Discarded_rings | "badrings" ]] which are rejected in the mapmaking process. These rings are also flagged by the "TotalFlag", as are the portions of rings longer than about 72.5 min, where the drift in the satellite's spin axis becomes important.<br />
<br />
===TAI TOI files===<br />
<br />
The TAI TOI files contain one extension with two columns, the first is the OBT value (exactly the same as reported in the SCI TOI), the second is the corresponding modified Julian day. Note that leap seconds were not added.<br />
<br />
{| border="1" cellpadding="3" cellspacing="0" align="center" style="text-align:left" width=800px<br />
|+ '''Time TAI TOI file data structure'''<br />
<br />
|- bgcolor="ffdead" <br />
!colspan="5" | 1. EXTNAME = "OBT-MJD" : Data columns<br />
|- bgcolor="ffdead" <br />
! Column name || Data type || Units || Description || Comment<br />
|-<br />
|OBT || Int*8 || 2<sup>-16</sup> sec || Onboard time ||<br />
|-<br />
|MJD || Real*8 || day || Modified Julian day ||<br />
|}<br />
<br />
===LFI OFF TOI files===<br />
The OFF (baseline) TOI files adopt the same file structure as the Science TOI files. Note that in case of OFF timelines related to the half-ring, an additional column is included in the OBT extension to define for each sample if it belongs to half-ring 1 or half-ring 2.<br />
<br />
===LFI HouseKeeping files===<br />
House keeping timelines are:<br />
* LFI_TOI_DAE-FAST-HK_R2.nn_ODxxxx.fits;<br />
* LFI_TOI_DAE-SlowConfiguration-HK_R2.nn_ODxxxx.fits;<br />
* LFI_TOI_DAE-SlowCurrent-HK_R2.nn_ODxxxx.fits;<br />
* LFI_TOI_DAE-SlowPhaseSwitch-HK_R2.nn_ODxxxx.fits;<br />
* LFI_TOI_DAE-SlowVoltage-HK_R2.nn_ODxxxx.fits;<br />
* LFI_TOI_REBA-HK_R2.nn_ODxxxx.fits;<br />
* SCS_TOI_EssentialASW-HK_R2.nn_ODxxxx.fits;<br />
* SCS_TOI_NonEssentialASW-HK_R2.nn_ODxxxx.fits.<br />
<br />
Each file contains two extensions, the first is the OBT (values are sampled every 1 or 10 seconds), while the second contains a variable number of columns equivalent to twice the number of Housekeeping timelines stored. Each Housekeeping datum is accompanied by its flag (normally "0" means that the value was considered invalid or out of limits). The Housekeeping names are the ones defined in the LFI Instrument Operation Manual.<br />
<br />
== References ==<br />
<br />
<References /><br />
<br />
[[Category:Mission products|001]]</div>Azaccheihttps://wiki.cosmos.esa.int/planck-legacy-archive/index.php?title=LFI-Validation&diff=14090LFI-Validation2018-07-06T11:09:06Z<p>Azacchei: /* 70 GHz internal consistency check */</p>
<hr />
<div>{{DISPLAYTITLE:Overall internal validation}}<br />
== Overview ==<br />
Data validation is critical at each step of the analysis pipeline. Much of the LFI data validation is based on null tests. Here we present some examples from the current release, with comments on relevant time scales and sensitivity to various systematics. In the 2018 release in addition we perform many test to verify the differences between this and previous release (see {{PlanckPapers|planck2016-l02}}).<br />
<br />
== Null tests approach ==<br />
Null tests at map level are performed routinely, whenever changes are made to the mapmaking pipeline. These include differences at survey, year, 2-year, half- mission and half-ring levels, for single detectors, horns, horn pairs and full frequency complements. Where possible, map differences are generated in <i>I</i>, <i>Q</i> and <i>U</i>. <br />
For this release, we use the Full Focal Plane 10 (FFP10) simulations for comparison. We can use FFP10 noise simulations, identical to the data in terms of sky sampling and with matching time domain noise characteristics, to make statistical arguments about the likelihood of the noise observed in the actual data nulls.<br />
In general null tests are performed to highlight possible issues in the data related to instrumental systematic effecst not properly accounted for within the processing pipeline, or related to known changes in the operational conditions (e.g., switch-over of the sorption coolers), or related to intrinsic instrument properties coupled with the sky signal, such as stray light contamination.<br />
Such null-tests can be performed by using data on different time scales ranging from 1 minute to 1 year of observations, at different unit levels (radiometer, horn, horn-pair), within frequency and cross-frequency, both in total intensity, and, when applicable, in polarization.<br />
<br />
=== Sample Null Maps ===<br />
<br />
[[File:Fig_13.png|thumb|center|900px]]<br />
<br />
This figure shows difefrences between 2018 and 1015 frequenncy maps in <i>I</i>, <i>Q</i> and <i>U</i>. Large scale differences between the two set of maps are mainly due to changes in the calibration procedure.<br />
<br />
[[File:Fig_14.png|thumb|center|900px]]<br />
<br />
In this figure we consider the set of odd-even survey differences combining all eight sky surveys covered by LFI. These survey combinations optimize the signal-to-noise ratio and highlight<br />
large-scale structures. The nine maps on the left show odd-even survey dfferences for the 2015 release, while the nine maps on the right show the same for the 2018 release. The 2015 data show large residuals in <i>I</i> at 30 and 44 GHz that bias the difference away from zero. This effect is considerably reduced in the 2018 release, as expected from the improvements in the calibration process. The <i>I</i> map at 70 GHz also shows a significant improvement. In the polarization maps, there is a general reduction in the amplitude of structures close to the Galactic plane.<br />
<br />
[[File:Fig_15.png|thumb|center|400px]]<br />
<br />
Finally here we shows pseudo-angular power spectra from the oddeven survey dfferences. There is great improvement in 2018 in removing largescale structures at 30 GHz in <i>TT</i>, <i>EE</i>, and somewhat in <i>BB</i>, and also in <i>TT</i> at 44 GHz.<br />
<br />
<br />
===Intra-frequency consistency check===<br />
We have tested the consistency between 30, 44, and 70GHz maps by comparing the power spectra in the multipole range around the first acoustic peak. In order to do so, we have removed the estimated contribution from unresolved point source from the spectra. We have then built scatter plots for the three frequency pairs, i.e., 70GHz versus 30 GHz, 70GHz versus 44GHz, and 44GHz versus 30GHz, and performed a linear fit, accounting for errors on both axes.<br />
The results reported below show that the three power spectra are consistent within the errors. Moreover, note that the current error budget does not account for foreground removal, calibration, and window function uncertainties. Hence, the observed agreement between spectra at different frequencies can be considered to be even more satisfactory.<br />
<br />
[[File:Fig_21.png|thumb|center|1200px]]<br />
<br />
<br />
===70 GHz internal consistency check===<br />
We use the Hausman test {{BibCite|polenta_CrossSpectra}} to assess the consistency of auto- and cross-spectral estimates at 70 GHz. We specifically define the statistic:<br />
<br />
:<math><br />
H_{\ell}=\left(\hat{C_{\ell}}-\tilde{C_{\ell}}\right)/\sqrt{{\rm Var}\left\{ \hat{C_{\ell}}-\tilde{C_{\ell}}\right\} },<br />
</math><br />
<br />
where <math>\hat{C_{\ell}}</math> and <math>\tilde{C_{\ell}}</math> represent auto- and<br />
cross-spectra, respectively. In order to combine information from different multipoles into a single quantity, we define<br />
<br />
:<math><br />
B_{L}(r)=\frac{1}{\sqrt{L}}\sum_{\ell=2}^{[Lr]}H_{\ell},r\in\left[0,1\right],<br />
</math><br />
<br />
where square brackets denote the integer part. The distribution of <i>B<sub>L</sub></i>(<i>r</i>)<br />
converges (in a functional sense) to a Brownian motion process, which can be studied through the statistics<br />
<i>s</i><sub>1</sub>=sup<sub><i>r</i></sub><i>B<sub>L</sub></i>(<i>r</i>),<br />
<i>s</i><sub>2</sub>=sup<sub><i>r</i></sub>|<i>B<sub>L</sub></i>(<i>r</i>)|, and<br />
<i>s</i><sub>3</sub>=&#8747;<sub>0</sub><sup>1</sup><i>B<sub>L</sub></i><sup>2</sup>(<i>r</i>)dr. Using the "FFP10" simulations,<br />
we derive empirical distributions for all the three test statistics and compare with results obtained from Planck data. We find that the Hausman test shows no statistically significant inconsistencies between the two spectral<br />
estimates.<br />
<br />
[[File:Fig_23.png|thumb|center|1200px|]]<br />
<br />
<!--<br />
== Data Release Results ==<br />
<br />
=== Impact on cosmology ===<br />
--><br />
<br />
== References ==<br />
<br />
<References /><br />
<br />
<br />
[[Category:LFI data processing|006]]</div>Azaccheihttps://wiki.cosmos.esa.int/planck-legacy-archive/index.php?title=LFI-Validation&diff=14089LFI-Validation2018-07-06T11:08:04Z<p>Azacchei: /* 70 GHz internal consistency check */</p>
<hr />
<div>{{DISPLAYTITLE:Overall internal validation}}<br />
== Overview ==<br />
Data validation is critical at each step of the analysis pipeline. Much of the LFI data validation is based on null tests. Here we present some examples from the current release, with comments on relevant time scales and sensitivity to various systematics. In the 2018 release in addition we perform many test to verify the differences between this and previous release (see {{PlanckPapers|planck2016-l02}}).<br />
<br />
== Null tests approach ==<br />
Null tests at map level are performed routinely, whenever changes are made to the mapmaking pipeline. These include differences at survey, year, 2-year, half- mission and half-ring levels, for single detectors, horns, horn pairs and full frequency complements. Where possible, map differences are generated in <i>I</i>, <i>Q</i> and <i>U</i>. <br />
For this release, we use the Full Focal Plane 10 (FFP10) simulations for comparison. We can use FFP10 noise simulations, identical to the data in terms of sky sampling and with matching time domain noise characteristics, to make statistical arguments about the likelihood of the noise observed in the actual data nulls.<br />
In general null tests are performed to highlight possible issues in the data related to instrumental systematic effecst not properly accounted for within the processing pipeline, or related to known changes in the operational conditions (e.g., switch-over of the sorption coolers), or related to intrinsic instrument properties coupled with the sky signal, such as stray light contamination.<br />
Such null-tests can be performed by using data on different time scales ranging from 1 minute to 1 year of observations, at different unit levels (radiometer, horn, horn-pair), within frequency and cross-frequency, both in total intensity, and, when applicable, in polarization.<br />
<br />
=== Sample Null Maps ===<br />
<br />
[[File:Fig_13.png|thumb|center|900px]]<br />
<br />
This figure shows difefrences between 2018 and 1015 frequenncy maps in <i>I</i>, <i>Q</i> and <i>U</i>. Large scale differences between the two set of maps are mainly due to changes in the calibration procedure.<br />
<br />
[[File:Fig_14.png|thumb|center|900px]]<br />
<br />
In this figure we consider the set of odd-even survey differences combining all eight sky surveys covered by LFI. These survey combinations optimize the signal-to-noise ratio and highlight<br />
large-scale structures. The nine maps on the left show odd-even survey dfferences for the 2015 release, while the nine maps on the right show the same for the 2018 release. The 2015 data show large residuals in <i>I</i> at 30 and 44 GHz that bias the difference away from zero. This effect is considerably reduced in the 2018 release, as expected from the improvements in the calibration process. The <i>I</i> map at 70 GHz also shows a significant improvement. In the polarization maps, there is a general reduction in the amplitude of structures close to the Galactic plane.<br />
<br />
[[File:Fig_15.png|thumb|center|400px]]<br />
<br />
Finally here we shows pseudo-angular power spectra from the oddeven survey dfferences. There is great improvement in 2018 in removing largescale structures at 30 GHz in <i>TT</i>, <i>EE</i>, and somewhat in <i>BB</i>, and also in <i>TT</i> at 44 GHz.<br />
<br />
<br />
===Intra-frequency consistency check===<br />
We have tested the consistency between 30, 44, and 70GHz maps by comparing the power spectra in the multipole range around the first acoustic peak. In order to do so, we have removed the estimated contribution from unresolved point source from the spectra. We have then built scatter plots for the three frequency pairs, i.e., 70GHz versus 30 GHz, 70GHz versus 44GHz, and 44GHz versus 30GHz, and performed a linear fit, accounting for errors on both axes.<br />
The results reported below show that the three power spectra are consistent within the errors. Moreover, note that the current error budget does not account for foreground removal, calibration, and window function uncertainties. Hence, the observed agreement between spectra at different frequencies can be considered to be even more satisfactory.<br />
<br />
[[File:Fig_21.png|thumb|center|1200px]]<br />
<br />
<br />
===70 GHz internal consistency check===<br />
We use the Hausman test {{BibCite|polenta_CrossSpectra}} to assess the consistency of auto- and cross-spectral estimates at 70 GHz. We specifically define the statistic:<br />
<br />
:<math><br />
H_{\ell}=\left(\hat{C_{\ell}}-\tilde{C_{\ell}}\right)/\sqrt{{\rm Var}\left\{ \hat{C_{\ell}}-\tilde{C_{\ell}}\right\} },<br />
</math><br />
<br />
where <math>\hat{C_{\ell}}</math> and <math>\tilde{C_{\ell}}</math> represent auto- and<br />
cross-spectra, respectively. In order to combine information from different multipoles into a single quantity, we define<br />
<br />
:<math><br />
B_{L}(r)=\frac{1}{\sqrt{L}}\sum_{\ell=2}^{[Lr]}H_{\ell},r\in\left[0,1\right],<br />
</math><br />
<br />
where square brackets denote the integer part. The distribution of <i>B<sub>L</sub></i>(<i>r</i>)<br />
converges (in a functional sense) to a Brownian motion process, which can be studied through the statistics<br />
<i>s</i><sub>1</sub>=sup<sub><i>r</i></sub><i>B<sub>L</sub></i>(<i>r</i>),<br />
<i>s</i><sub>2</sub>=sup<sub><i>r</i></sub>|<i>B<sub>L</sub></i>(<i>r</i>)|, and<br />
<i>s</i><sub>3</sub>=&#8747;<sub>0</sub><sup>1</sup><i>B<sub>L</sub></i><sup>2</sup>(<i>r</i>)dr. Using the "FFP7" simulations,<br />
we derive empirical distributions for all the three test statistics and compare with results obtained from Planck data<br />
(see Fig. 7). We find that the Hausman test shows no statistically significant inconsistencies between the two spectral<br />
estimates.<br />
<br />
[[File:Fig_23.png|thumb|center|1200px|]]<br />
<br />
<!--<br />
== Data Release Results ==<br />
<br />
=== Impact on cosmology ===<br />
--><br />
<br />
== References ==<br />
<br />
<References /><br />
<br />
<br />
[[Category:LFI data processing|006]]</div>Azaccheihttps://wiki.cosmos.esa.int/planck-legacy-archive/index.php?title=LFI-Validation&diff=14088LFI-Validation2018-07-06T11:07:28Z<p>Azacchei: /* 70 GHz internal consistency check */</p>
<hr />
<div>{{DISPLAYTITLE:Overall internal validation}}<br />
== Overview ==<br />
Data validation is critical at each step of the analysis pipeline. Much of the LFI data validation is based on null tests. Here we present some examples from the current release, with comments on relevant time scales and sensitivity to various systematics. In the 2018 release in addition we perform many test to verify the differences between this and previous release (see {{PlanckPapers|planck2016-l02}}).<br />
<br />
== Null tests approach ==<br />
Null tests at map level are performed routinely, whenever changes are made to the mapmaking pipeline. These include differences at survey, year, 2-year, half- mission and half-ring levels, for single detectors, horns, horn pairs and full frequency complements. Where possible, map differences are generated in <i>I</i>, <i>Q</i> and <i>U</i>. <br />
For this release, we use the Full Focal Plane 10 (FFP10) simulations for comparison. We can use FFP10 noise simulations, identical to the data in terms of sky sampling and with matching time domain noise characteristics, to make statistical arguments about the likelihood of the noise observed in the actual data nulls.<br />
In general null tests are performed to highlight possible issues in the data related to instrumental systematic effecst not properly accounted for within the processing pipeline, or related to known changes in the operational conditions (e.g., switch-over of the sorption coolers), or related to intrinsic instrument properties coupled with the sky signal, such as stray light contamination.<br />
Such null-tests can be performed by using data on different time scales ranging from 1 minute to 1 year of observations, at different unit levels (radiometer, horn, horn-pair), within frequency and cross-frequency, both in total intensity, and, when applicable, in polarization.<br />
<br />
=== Sample Null Maps ===<br />
<br />
[[File:Fig_13.png|thumb|center|900px]]<br />
<br />
This figure shows difefrences between 2018 and 1015 frequenncy maps in <i>I</i>, <i>Q</i> and <i>U</i>. Large scale differences between the two set of maps are mainly due to changes in the calibration procedure.<br />
<br />
[[File:Fig_14.png|thumb|center|900px]]<br />
<br />
In this figure we consider the set of odd-even survey differences combining all eight sky surveys covered by LFI. These survey combinations optimize the signal-to-noise ratio and highlight<br />
large-scale structures. The nine maps on the left show odd-even survey dfferences for the 2015 release, while the nine maps on the right show the same for the 2018 release. The 2015 data show large residuals in <i>I</i> at 30 and 44 GHz that bias the difference away from zero. This effect is considerably reduced in the 2018 release, as expected from the improvements in the calibration process. The <i>I</i> map at 70 GHz also shows a significant improvement. In the polarization maps, there is a general reduction in the amplitude of structures close to the Galactic plane.<br />
<br />
[[File:Fig_15.png|thumb|center|400px]]<br />
<br />
Finally here we shows pseudo-angular power spectra from the oddeven survey dfferences. There is great improvement in 2018 in removing largescale structures at 30 GHz in <i>TT</i>, <i>EE</i>, and somewhat in <i>BB</i>, and also in <i>TT</i> at 44 GHz.<br />
<br />
<br />
===Intra-frequency consistency check===<br />
We have tested the consistency between 30, 44, and 70GHz maps by comparing the power spectra in the multipole range around the first acoustic peak. In order to do so, we have removed the estimated contribution from unresolved point source from the spectra. We have then built scatter plots for the three frequency pairs, i.e., 70GHz versus 30 GHz, 70GHz versus 44GHz, and 44GHz versus 30GHz, and performed a linear fit, accounting for errors on both axes.<br />
The results reported below show that the three power spectra are consistent within the errors. Moreover, note that the current error budget does not account for foreground removal, calibration, and window function uncertainties. Hence, the observed agreement between spectra at different frequencies can be considered to be even more satisfactory.<br />
<br />
[[File:Fig_21.png|thumb|center|1200px]]<br />
<br />
<br />
===70 GHz internal consistency check===<br />
We use the Hausman test {{BibCite|polenta_CrossSpectra}} to assess the consistency of auto- and cross-spectral estimates at 70 GHz. We specifically define the statistic:<br />
<br />
:<math><br />
H_{\ell}=\left(\hat{C_{\ell}}-\tilde{C_{\ell}}\right)/\sqrt{{\rm Var}\left\{ \hat{C_{\ell}}-\tilde{C_{\ell}}\right\} },<br />
</math><br />
<br />
where <math>\hat{C_{\ell}}</math> and <math>\tilde{C_{\ell}}</math> represent auto- and<br />
cross-spectra, respectively. In order to combine information from different multipoles into a single quantity, we define<br />
<br />
:<math><br />
B_{L}(r)=\frac{1}{\sqrt{L}}\sum_{\ell=2}^{[Lr]}H_{\ell},r\in\left[0,1\right],<br />
</math><br />
<br />
where square brackets denote the integer part. The distribution of <i>B<sub>L</sub></i>(<i>r</i>)<br />
converges (in a functional sense) to a Brownian motion process, which can be studied through the statistics<br />
<i>s</i><sub>1</sub>=sup<sub><i>r</i></sub><i>B<sub>L</sub></i>(<i>r</i>),<br />
<i>s</i><sub>2</sub>=sup<sub><i>r</i></sub>|<i>B<sub>L</sub></i>(<i>r</i>)|, and<br />
<i>s</i><sub>3</sub>=&#8747;<sub>0</sub><sup>1</sup><i>B<sub>L</sub></i><sup>2</sup>(<i>r</i>)dr. Using the "FFP7" simulations,<br />
we derive empirical distributions for all the three test statistics and compare with results obtained from Planck data<br />
(see Fig. 7). We find that the Hausman test shows no statistically significant inconsistencies between the two spectral<br />
estimates.<br />
<br />
[[File:Fig_23.jpg|thumb|center|1200px|]]<br />
<br />
<!--<br />
== Data Release Results ==<br />
<br />
=== Impact on cosmology ===<br />
--><br />
<br />
== References ==<br />
<br />
<References /><br />
<br />
<br />
[[Category:LFI data processing|006]]</div>Azaccheihttps://wiki.cosmos.esa.int/planck-legacy-archive/index.php?title=File:Fig_23.png&diff=14087File:Fig 23.png2018-07-06T11:06:04Z<p>Azacchei: </p>
<hr />
<div></div>Azaccheihttps://wiki.cosmos.esa.int/planck-legacy-archive/index.php?title=LFI-Validation&diff=14086LFI-Validation2018-07-06T11:03:38Z<p>Azacchei: </p>
<hr />
<div>{{DISPLAYTITLE:Overall internal validation}}<br />
== Overview ==<br />
Data validation is critical at each step of the analysis pipeline. Much of the LFI data validation is based on null tests. Here we present some examples from the current release, with comments on relevant time scales and sensitivity to various systematics. In the 2018 release in addition we perform many test to verify the differences between this and previous release (see {{PlanckPapers|planck2016-l02}}).<br />
<br />
== Null tests approach ==<br />
Null tests at map level are performed routinely, whenever changes are made to the mapmaking pipeline. These include differences at survey, year, 2-year, half- mission and half-ring levels, for single detectors, horns, horn pairs and full frequency complements. Where possible, map differences are generated in <i>I</i>, <i>Q</i> and <i>U</i>. <br />
For this release, we use the Full Focal Plane 10 (FFP10) simulations for comparison. We can use FFP10 noise simulations, identical to the data in terms of sky sampling and with matching time domain noise characteristics, to make statistical arguments about the likelihood of the noise observed in the actual data nulls.<br />
In general null tests are performed to highlight possible issues in the data related to instrumental systematic effecst not properly accounted for within the processing pipeline, or related to known changes in the operational conditions (e.g., switch-over of the sorption coolers), or related to intrinsic instrument properties coupled with the sky signal, such as stray light contamination.<br />
Such null-tests can be performed by using data on different time scales ranging from 1 minute to 1 year of observations, at different unit levels (radiometer, horn, horn-pair), within frequency and cross-frequency, both in total intensity, and, when applicable, in polarization.<br />
<br />
=== Sample Null Maps ===<br />
<br />
[[File:Fig_13.png|thumb|center|900px]]<br />
<br />
This figure shows difefrences between 2018 and 1015 frequenncy maps in <i>I</i>, <i>Q</i> and <i>U</i>. Large scale differences between the two set of maps are mainly due to changes in the calibration procedure.<br />
<br />
[[File:Fig_14.png|thumb|center|900px]]<br />
<br />
In this figure we consider the set of odd-even survey differences combining all eight sky surveys covered by LFI. These survey combinations optimize the signal-to-noise ratio and highlight<br />
large-scale structures. The nine maps on the left show odd-even survey dfferences for the 2015 release, while the nine maps on the right show the same for the 2018 release. The 2015 data show large residuals in <i>I</i> at 30 and 44 GHz that bias the difference away from zero. This effect is considerably reduced in the 2018 release, as expected from the improvements in the calibration process. The <i>I</i> map at 70 GHz also shows a significant improvement. In the polarization maps, there is a general reduction in the amplitude of structures close to the Galactic plane.<br />
<br />
[[File:Fig_15.png|thumb|center|400px]]<br />
<br />
Finally here we shows pseudo-angular power spectra from the oddeven survey dfferences. There is great improvement in 2018 in removing largescale structures at 30 GHz in <i>TT</i>, <i>EE</i>, and somewhat in <i>BB</i>, and also in <i>TT</i> at 44 GHz.<br />
<br />
<br />
===Intra-frequency consistency check===<br />
We have tested the consistency between 30, 44, and 70GHz maps by comparing the power spectra in the multipole range around the first acoustic peak. In order to do so, we have removed the estimated contribution from unresolved point source from the spectra. We have then built scatter plots for the three frequency pairs, i.e., 70GHz versus 30 GHz, 70GHz versus 44GHz, and 44GHz versus 30GHz, and performed a linear fit, accounting for errors on both axes.<br />
The results reported below show that the three power spectra are consistent within the errors. Moreover, note that the current error budget does not account for foreground removal, calibration, and window function uncertainties. Hence, the observed agreement between spectra at different frequencies can be considered to be even more satisfactory.<br />
<br />
[[File:Fig_21.png|thumb|center|1200px]]<br />
<br />
<br />
===70 GHz internal consistency check===<br />
We use the Hausman test {{BibCite|polenta_CrossSpectra}} to assess the consistency of auto- and cross-spectral estimates at 70 GHz. We specifically define the statistic:<br />
<br />
:<math><br />
H_{\ell}=\left(\hat{C_{\ell}}-\tilde{C_{\ell}}\right)/\sqrt{{\rm Var}\left\{ \hat{C_{\ell}}-\tilde{C_{\ell}}\right\} },<br />
</math><br />
<br />
where <math>\hat{C_{\ell}}</math> and <math>\tilde{C_{\ell}}</math> represent auto- and<br />
cross-spectra, respectively. In order to combine information from different multipoles into a single quantity, we define<br />
<br />
:<math><br />
B_{L}(r)=\frac{1}{\sqrt{L}}\sum_{\ell=2}^{[Lr]}H_{\ell},r\in\left[0,1\right],<br />
</math><br />
<br />
where square brackets denote the integer part. The distribution of <i>B<sub>L</sub></i>(<i>r</i>)<br />
converges (in a functional sense) to a Brownian motion process, which can be studied through the statistics<br />
<i>s</i><sub>1</sub>=sup<sub><i>r</i></sub><i>B<sub>L</sub></i>(<i>r</i>),<br />
<i>s</i><sub>2</sub>=sup<sub><i>r</i></sub>|<i>B<sub>L</sub></i>(<i>r</i>)|, and<br />
<i>s</i><sub>3</sub>=&#8747;<sub>0</sub><sup>1</sup><i>B<sub>L</sub></i><sup>2</sup>(<i>r</i>)dr. Using the "FFP7" simulations,<br />
we derive empirical distributions for all the three test statistics and compare with results obtained from Planck data<br />
(see Fig. 7). We find that the Hausman test shows no statistically significant inconsistencies between the two spectral<br />
estimates.<br />
<br />
[[File:cons2.jpg|thumb|center|800px|'''Figure 7: From left to right, the empirical<br />
distribution (estimated via FFP7) of the <i>s</i><sub>1</sub>, <i>s</i><sub>2</sub>, and <i>s</i><sub>3</sub><br />
statistics (see text). The vertical line represents 70GHz data.''']]<br />
<br />
As a further test, we have estimated the temperature power spectrum for each of three horn-pair maps, and have compared the<br />
results with the spectrum obtained from all 12 radiometers shown above. In Fig. 8 we plot the<br />
difference between the horn-pair and the combined power spectra.<br />
Again, the error bars have been estimated from the FFP7 simulated data set. A &chi;<sup>2</sup> analysis of the residual shows that they are compatible with the null hypothesis, confirming the<br />
strong consistency of the estimates.<br />
<br />
[[File:cons3.jpg|thumb|center|500px|'''Figure 8: Residuals between the auto-power spectra of the horn-pair maps and the power spectrum of the full 70GHz frequency map. Error bars here are derived from FFP7 simulations.''']]<br />
<br />
<!--<br />
== Data Release Results ==<br />
<br />
=== Impact on cosmology ===<br />
--><br />
<br />
== References ==<br />
<br />
<References /><br />
<br />
<br />
[[Category:LFI data processing|006]]</div>Azaccheihttps://wiki.cosmos.esa.int/planck-legacy-archive/index.php?title=LFI-Validation&diff=14085LFI-Validation2018-07-06T11:02:41Z<p>Azacchei: </p>
<hr />
<div>{{DISPLAYTITLE:Overall internal validation}}<br />
== Overview ==<br />
Data validation is critical at each step of the analysis pipeline. Much of the LFI data validation is based on null tests. Here we present some examples from the current release, with comments on relevant time scales and sensitivity to various systematics. In the 2018 release in addition we perform many test to verify the differences between this and previous release (see {{PlanckPapers|planck2016-l02}}).<br />
<br />
== Null tests approach ==<br />
Null tests at map level are performed routinely, whenever changes are made to the mapmaking pipeline. These include differences at survey, year, 2-year, half- mission and half-ring levels, for single detectors, horns, horn pairs and full frequency complements. Where possible, map differences are generated in <i>I</i>, <i>Q</i> and <i>U</i>. <br />
For this release, we use the Full Focal Plane 10 (FFP10) simulations for comparison. We can use FFP10 noise simulations, identical to the data in terms of sky sampling and with matching time domain noise characteristics, to make statistical arguments about the likelihood of the noise observed in the actual data nulls.<br />
In general null tests are performed to highlight possible issues in the data related to instrumental systematic effecst not properly accounted for within the processing pipeline, or related to known changes in the operational conditions (e.g., switch-over of the sorption coolers), or related to intrinsic instrument properties coupled with the sky signal, such as stray light contamination.<br />
Such null-tests can be performed by using data on different time scales ranging from 1 minute to 1 year of observations, at different unit levels (radiometer, horn, horn-pair), within frequency and cross-frequency, both in total intensity, and, when applicable, in polarization.<br />
<br />
=== Sample Null Maps ===<br />
<br />
[[File:Fig_13.png|thumb|center|900px]]<br />
<br />
This figure shows difefrences between 2018 and 1015 frequenncy maps in <i>I</i>, <i>Q</i> and <i>U</i>. Large scale differences between the two set of maps are mainly due to changes in the calibration procedure.<br />
<br />
[File:Fig_14.png|thumb|center|900px]<br />
<br />
In this figure we consider the set of odd-even survey differences combining all eight sky surveys covered by LFI. These survey combinations optimize the signal-to-noise ratio and highlight<br />
large-scale structures. The nine maps on the left show odd-even survey dfferences for the 2015 release, while the nine maps on the right show the same for the 2018 release. The 2015 data show large residuals in <i>I</i> at 30 and 44 GHz that bias the difference away from zero. This effect is considerably reduced in the 2018 release, as expected from the improvements in the calibration process. The <i>I</i> map at 70 GHz also shows a significant improvement. In the polarization maps, there is a general reduction in the amplitude of structures close to the Galactic plane.<br />
<br />
[[File:Fig_15.png|thumb|center|400px]]<br />
<br />
Finally here we shows pseudo-angular power spectra from the oddeven survey dfferences. There is great improvement in 2018 in removing largescale structures at 30 GHz in <i>TT</i>, <i>EE</i>, and somewhat in <i>BB</i>, and also in <i>TT</i> at 44 GHz.<br />
<br />
<br />
===Intra-frequency consistency check===<br />
We have tested the consistency between 30, 44, and 70GHz maps by comparing the power spectra in the multipole range around the first acoustic peak. In order to do so, we have removed the estimated contribution from unresolved point source from the spectra. We have then built scatter plots for the three frequency pairs, i.e., 70GHz versus 30 GHz, 70GHz versus 44GHz, and 44GHz versus 30GHz, and performed a linear fit, accounting for errors on both axes.<br />
The results reported below show that the three power spectra are consistent within the errors. Moreover, note that the current error budget does not account for foreground removal, calibration, and window function uncertainties. Hence, the observed agreement between spectra at different frequencies can be considered to be even more satisfactory.<br />
<br />
[File:Fig_21.png|thumb|center|1200px]<br />
<br />
<br />
===70 GHz internal consistency check===<br />
We use the Hausman test {{BibCite|polenta_CrossSpectra}} to assess the consistency of auto- and cross-spectral estimates at 70 GHz. We specifically define the statistic:<br />
<br />
:<math><br />
H_{\ell}=\left(\hat{C_{\ell}}-\tilde{C_{\ell}}\right)/\sqrt{{\rm Var}\left\{ \hat{C_{\ell}}-\tilde{C_{\ell}}\right\} },<br />
</math><br />
<br />
where <math>\hat{C_{\ell}}</math> and <math>\tilde{C_{\ell}}</math> represent auto- and<br />
cross-spectra, respectively. In order to combine information from different multipoles into a single quantity, we define<br />
<br />
:<math><br />
B_{L}(r)=\frac{1}{\sqrt{L}}\sum_{\ell=2}^{[Lr]}H_{\ell},r\in\left[0,1\right],<br />
</math><br />
<br />
where square brackets denote the integer part. The distribution of <i>B<sub>L</sub></i>(<i>r</i>)<br />
converges (in a functional sense) to a Brownian motion process, which can be studied through the statistics<br />
<i>s</i><sub>1</sub>=sup<sub><i>r</i></sub><i>B<sub>L</sub></i>(<i>r</i>),<br />
<i>s</i><sub>2</sub>=sup<sub><i>r</i></sub>|<i>B<sub>L</sub></i>(<i>r</i>)|, and<br />
<i>s</i><sub>3</sub>=&#8747;<sub>0</sub><sup>1</sup><i>B<sub>L</sub></i><sup>2</sup>(<i>r</i>)dr. Using the "FFP7" simulations,<br />
we derive empirical distributions for all the three test statistics and compare with results obtained from Planck data<br />
(see Fig. 7). We find that the Hausman test shows no statistically significant inconsistencies between the two spectral<br />
estimates.<br />
<br />
[[File:cons2.jpg|thumb|center|800px|'''Figure 7: From left to right, the empirical<br />
distribution (estimated via FFP7) of the <i>s</i><sub>1</sub>, <i>s</i><sub>2</sub>, and <i>s</i><sub>3</sub><br />
statistics (see text). The vertical line represents 70GHz data.''']]<br />
<br />
As a further test, we have estimated the temperature power spectrum for each of three horn-pair maps, and have compared the<br />
results with the spectrum obtained from all 12 radiometers shown above. In Fig. 8 we plot the<br />
difference between the horn-pair and the combined power spectra.<br />
Again, the error bars have been estimated from the FFP7 simulated data set. A &chi;<sup>2</sup> analysis of the residual shows that they are compatible with the null hypothesis, confirming the<br />
strong consistency of the estimates.<br />
<br />
[[File:cons3.jpg|thumb|center|500px|'''Figure 8: Residuals between the auto-power spectra of the horn-pair maps and the power spectrum of the full 70GHz frequency map. Error bars here are derived from FFP7 simulations.''']]<br />
<br />
<!--<br />
== Data Release Results ==<br />
<br />
=== Impact on cosmology ===<br />
--><br />
<br />
== References ==<br />
<br />
<References /><br />
<br />
<br />
[[Category:LFI data processing|006]]</div>Azaccheihttps://wiki.cosmos.esa.int/planck-legacy-archive/index.php?title=LFI-Validation&diff=14084LFI-Validation2018-07-06T11:01:59Z<p>Azacchei: </p>
<hr />
<div>{{DISPLAYTITLE:Overall internal validation}}<br />
== Overview ==<br />
Data validation is critical at each step of the analysis pipeline. Much of the LFI data validation is based on null tests. Here we present some examples from the current release, with comments on relevant time scales and sensitivity to various systematics. In the 2018 release in addition we perform many test to verify the differences between this and previous release (see {{PlanckPapers|planck2016-l02}}).<br />
<br />
== Null tests approach ==<br />
Null tests at map level are performed routinely, whenever changes are made to the mapmaking pipeline. These include differences at survey, year, 2-year, half- mission and half-ring levels, for single detectors, horns, horn pairs and full frequency complements. Where possible, map differences are generated in <i>I</i>, <i>Q</i> and <i>U</i>. <br />
For this release, we use the Full Focal Plane 10 (FFP10) simulations for comparison. We can use FFP10 noise simulations, identical to the data in terms of sky sampling and with matching time domain noise characteristics, to make statistical arguments about the likelihood of the noise observed in the actual data nulls.<br />
In general null tests are performed to highlight possible issues in the data related to instrumental systematic effecst not properly accounted for within the processing pipeline, or related to known changes in the operational conditions (e.g., switch-over of the sorption coolers), or related to intrinsic instrument properties coupled with the sky signal, such as stray light contamination.<br />
Such null-tests can be performed by using data on different time scales ranging from 1 minute to 1 year of observations, at different unit levels (radiometer, horn, horn-pair), within frequency and cross-frequency, both in total intensity, and, when applicable, in polarization.<br />
<br />
=== Sample Null Maps ===<br />
<br />
[[File:Fig_13.png|thumb|center|900px]]<br />
<br />
This figure shows difefrences between 2018 and 1015 frequenncy maps in <i>I</i>, <i>Q</i> and <i>U</i>. Large scale differences between the two set of maps are mainly due to changes in the calibration procedure.<br />
<br />
[File:Fig_14.png|thumb|center|1200px]<br />
<br />
In this figure we consider the set of odd-even survey differences combining all eight sky surveys covered by LFI. These survey combinations optimize the signal-to-noise ratio and highlight<br />
large-scale structures. The nine maps on the left show odd-even survey dfferences for the 2015 release, while the nine maps on the right show the same for the 2018 release. The 2015 data show large residuals in <i>I</i> at 30 and 44 GHz that bias the difference away from zero. This effect is considerably reduced in the 2018 release, as expected from the improvements in the calibration process. The <i>I</i> map at 70 GHz also shows a significant improvement. In the polarization maps, there is a general reduction in the amplitude of structures close to the Galactic plane.<br />
<br />
[[File:Fig_15.png|thumb|center|400px]]<br />
<br />
Finally here we shows pseudo-angular power spectra from the oddeven survey dfferences. There is great improvement in 2018 in removing largescale structures at 30 GHz in <i>TT</i>, <i>EE</i>, and somewhat in <i>BB</i>, and also in <i>TT</i> at 44 GHz.<br />
<br />
<br />
===Intra-frequency consistency check===<br />
We have tested the consistency between 30, 44, and 70GHz maps by comparing the power spectra in the multipole range around the first acoustic peak. In order to do so, we have removed the estimated contribution from unresolved point source from the spectra. We have then built scatter plots for the three frequency pairs, i.e., 70GHz versus 30 GHz, 70GHz versus 44GHz, and 44GHz versus 30GHz, and performed a linear fit, accounting for errors on both axes.<br />
The results reported below show that the three power spectra are consistent within the errors. Moreover, note that the current error budget does not account for foreground removal, calibration, and window function uncertainties. Hence, the observed agreement between spectra at different frequencies can be considered to be even more satisfactory.<br />
<br />
[[File:Fig_21.png|thumb|center|500px]]<br />
<br />
<br />
===70 GHz internal consistency check===<br />
We use the Hausman test {{BibCite|polenta_CrossSpectra}} to assess the consistency of auto- and cross-spectral estimates at 70 GHz. We specifically define the statistic:<br />
<br />
:<math><br />
H_{\ell}=\left(\hat{C_{\ell}}-\tilde{C_{\ell}}\right)/\sqrt{{\rm Var}\left\{ \hat{C_{\ell}}-\tilde{C_{\ell}}\right\} },<br />
</math><br />
<br />
where <math>\hat{C_{\ell}}</math> and <math>\tilde{C_{\ell}}</math> represent auto- and<br />
cross-spectra, respectively. In order to combine information from different multipoles into a single quantity, we define<br />
<br />
:<math><br />
B_{L}(r)=\frac{1}{\sqrt{L}}\sum_{\ell=2}^{[Lr]}H_{\ell},r\in\left[0,1\right],<br />
</math><br />
<br />
where square brackets denote the integer part. The distribution of <i>B<sub>L</sub></i>(<i>r</i>)<br />
converges (in a functional sense) to a Brownian motion process, which can be studied through the statistics<br />
<i>s</i><sub>1</sub>=sup<sub><i>r</i></sub><i>B<sub>L</sub></i>(<i>r</i>),<br />
<i>s</i><sub>2</sub>=sup<sub><i>r</i></sub>|<i>B<sub>L</sub></i>(<i>r</i>)|, and<br />
<i>s</i><sub>3</sub>=&#8747;<sub>0</sub><sup>1</sup><i>B<sub>L</sub></i><sup>2</sup>(<i>r</i>)dr. Using the "FFP7" simulations,<br />
we derive empirical distributions for all the three test statistics and compare with results obtained from Planck data<br />
(see Fig. 7). We find that the Hausman test shows no statistically significant inconsistencies between the two spectral<br />
estimates.<br />
<br />
[[File:cons2.jpg|thumb|center|800px|'''Figure 7: From left to right, the empirical<br />
distribution (estimated via FFP7) of the <i>s</i><sub>1</sub>, <i>s</i><sub>2</sub>, and <i>s</i><sub>3</sub><br />
statistics (see text). The vertical line represents 70GHz data.''']]<br />
<br />
As a further test, we have estimated the temperature power spectrum for each of three horn-pair maps, and have compared the<br />
results with the spectrum obtained from all 12 radiometers shown above. In Fig. 8 we plot the<br />
difference between the horn-pair and the combined power spectra.<br />
Again, the error bars have been estimated from the FFP7 simulated data set. A &chi;<sup>2</sup> analysis of the residual shows that they are compatible with the null hypothesis, confirming the<br />
strong consistency of the estimates.<br />
<br />
[[File:cons3.jpg|thumb|center|500px|'''Figure 8: Residuals between the auto-power spectra of the horn-pair maps and the power spectrum of the full 70GHz frequency map. Error bars here are derived from FFP7 simulations.''']]<br />
<br />
<!--<br />
== Data Release Results ==<br />
<br />
=== Impact on cosmology ===<br />
--><br />
<br />
== References ==<br />
<br />
<References /><br />
<br />
<br />
[[Category:LFI data processing|006]]</div>Azaccheihttps://wiki.cosmos.esa.int/planck-legacy-archive/index.php?title=LFI-Validation&diff=14083LFI-Validation2018-07-06T11:01:12Z<p>Azacchei: </p>
<hr />
<div>{{DISPLAYTITLE:Overall internal validation}}<br />
== Overview ==<br />
Data validation is critical at each step of the analysis pipeline. Much of the LFI data validation is based on null tests. Here we present some examples from the current release, with comments on relevant time scales and sensitivity to various systematics. In the 2018 release in addition we perform many test to verify the differences between this and previous release (see {{PlanckPapers|planck2016-l02}}).<br />
<br />
== Null tests approach ==<br />
Null tests at map level are performed routinely, whenever changes are made to the mapmaking pipeline. These include differences at survey, year, 2-year, half- mission and half-ring levels, for single detectors, horns, horn pairs and full frequency complements. Where possible, map differences are generated in <i>I</i>, <i>Q</i> and <i>U</i>. <br />
For this release, we use the Full Focal Plane 10 (FFP10) simulations for comparison. We can use FFP10 noise simulations, identical to the data in terms of sky sampling and with matching time domain noise characteristics, to make statistical arguments about the likelihood of the noise observed in the actual data nulls.<br />
In general null tests are performed to highlight possible issues in the data related to instrumental systematic effecst not properly accounted for within the processing pipeline, or related to known changes in the operational conditions (e.g., switch-over of the sorption coolers), or related to intrinsic instrument properties coupled with the sky signal, such as stray light contamination.<br />
Such null-tests can be performed by using data on different time scales ranging from 1 minute to 1 year of observations, at different unit levels (radiometer, horn, horn-pair), within frequency and cross-frequency, both in total intensity, and, when applicable, in polarization.<br />
<br />
=== Sample Null Maps ===<br />
<br />
[[File:Fig_13.png|thumb|center|900px]]<br />
<br />
This figure shows difefrences between 2018 and 1015 frequenncy maps in <i>I</i>, <i>Q</i> and <i>U</i>. Large scale differences between the two set of maps are mainly due to changes in the calibration procedure.<br />
<br />
[[File:Fig_14.png|thumb|center|900px]]<br />
<br />
In this figure we consider the set of odd-even survey differences combining all eight sky surveys covered by LFI. These survey combinations optimize the signal-to-noise ratio and highlight<br />
large-scale structures. The nine maps on the left show odd-even survey dfferences for the 2015 release, while the nine maps on the right show the same for the 2018 release. The 2015 data show large residuals in <i>I</i> at 30 and 44 GHz that bias the difference away from zero. This effect is considerably reduced in the 2018 release, as expected from the improvements in the calibration process. The <i>I</i> map at 70 GHz also shows a significant improvement. In the polarization maps, there is a general reduction in the amplitude of structures close to the Galactic plane.<br />
<br />
[[File:Fig_15.png|thumb|center|400px]]<br />
<br />
Finally here we shows pseudo-angular power spectra from the oddeven survey dfferences. There is great improvement in 2018 in removing largescale structures at 30 GHz in <i>TT</i>, <i>EE</i>, and somewhat in <i>BB</i>, and also in <i>TT</i> at 44 GHz.<br />
<br />
<br />
===Intra-frequency consistency check===<br />
We have tested the consistency between 30, 44, and 70GHz maps by comparing the power spectra in the multipole range around the first acoustic peak. In order to do so, we have removed the estimated contribution from unresolved point source from the spectra. We have then built scatter plots for the three frequency pairs, i.e., 70GHz versus 30 GHz, 70GHz versus 44GHz, and 44GHz versus 30GHz, and performed a linear fit, accounting for errors on both axes.<br />
The results reported below show that the three power spectra are consistent within the errors. Moreover, note that the current error budget does not account for foreground removal, calibration, and window function uncertainties. Hence, the observed agreement between spectra at different frequencies can be considered to be even more satisfactory.<br />
<br />
[[File:Fig_21.png|thumb|center|500px]]<br />
<br />
<br />
===70 GHz internal consistency check===<br />
We use the Hausman test {{BibCite|polenta_CrossSpectra}} to assess the consistency of auto- and cross-spectral estimates at 70 GHz. We specifically define the statistic:<br />
<br />
:<math><br />
H_{\ell}=\left(\hat{C_{\ell}}-\tilde{C_{\ell}}\right)/\sqrt{{\rm Var}\left\{ \hat{C_{\ell}}-\tilde{C_{\ell}}\right\} },<br />
</math><br />
<br />
where <math>\hat{C_{\ell}}</math> and <math>\tilde{C_{\ell}}</math> represent auto- and<br />
cross-spectra, respectively. In order to combine information from different multipoles into a single quantity, we define<br />
<br />
:<math><br />
B_{L}(r)=\frac{1}{\sqrt{L}}\sum_{\ell=2}^{[Lr]}H_{\ell},r\in\left[0,1\right],<br />
</math><br />
<br />
where square brackets denote the integer part. The distribution of <i>B<sub>L</sub></i>(<i>r</i>)<br />
converges (in a functional sense) to a Brownian motion process, which can be studied through the statistics<br />
<i>s</i><sub>1</sub>=sup<sub><i>r</i></sub><i>B<sub>L</sub></i>(<i>r</i>),<br />
<i>s</i><sub>2</sub>=sup<sub><i>r</i></sub>|<i>B<sub>L</sub></i>(<i>r</i>)|, and<br />
<i>s</i><sub>3</sub>=&#8747;<sub>0</sub><sup>1</sup><i>B<sub>L</sub></i><sup>2</sup>(<i>r</i>)dr. Using the "FFP7" simulations,<br />
we derive empirical distributions for all the three test statistics and compare with results obtained from Planck data<br />
(see Fig. 7). We find that the Hausman test shows no statistically significant inconsistencies between the two spectral<br />
estimates.<br />
<br />
[[File:cons2.jpg|thumb|center|800px|'''Figure 7: From left to right, the empirical<br />
distribution (estimated via FFP7) of the <i>s</i><sub>1</sub>, <i>s</i><sub>2</sub>, and <i>s</i><sub>3</sub><br />
statistics (see text). The vertical line represents 70GHz data.''']]<br />
<br />
As a further test, we have estimated the temperature power spectrum for each of three horn-pair maps, and have compared the<br />
results with the spectrum obtained from all 12 radiometers shown above. In Fig. 8 we plot the<br />
difference between the horn-pair and the combined power spectra.<br />
Again, the error bars have been estimated from the FFP7 simulated data set. A &chi;<sup>2</sup> analysis of the residual shows that they are compatible with the null hypothesis, confirming the<br />
strong consistency of the estimates.<br />
<br />
[[File:cons3.jpg|thumb|center|500px|'''Figure 8: Residuals between the auto-power spectra of the horn-pair maps and the power spectrum of the full 70GHz frequency map. Error bars here are derived from FFP7 simulations.''']]<br />
<br />
<!--<br />
== Data Release Results ==<br />
<br />
=== Impact on cosmology ===<br />
--><br />
<br />
== References ==<br />
<br />
<References /><br />
<br />
<br />
[[Category:LFI data processing|006]]</div>Azaccheihttps://wiki.cosmos.esa.int/planck-legacy-archive/index.php?title=LFI-Validation&diff=14082LFI-Validation2018-07-06T10:58:34Z<p>Azacchei: </p>
<hr />
<div>{{DISPLAYTITLE:Overall internal validation}}<br />
== Overview ==<br />
Data validation is critical at each step of the analysis pipeline. Much of the LFI data validation is based on null tests. Here we present some examples from the current release, with comments on relevant time scales and sensitivity to various systematics. In the 2018 release in addition we perform many test to verify the differences between this and previous release (see {{PlanckPapers|planck2016-l02}}).<br />
<br />
== Null tests approach ==<br />
Null tests at map level are performed routinely, whenever changes are made to the mapmaking pipeline. These include differences at survey, year, 2-year, half- mission and half-ring levels, for single detectors, horns, horn pairs and full frequency complements. Where possible, map differences are generated in <i>I</i>, <i>Q</i> and <i>U</i>. <br />
For this release, we use the Full Focal Plane 10 (FFP10) simulations for comparison. We can use FFP10 noise simulations, identical to the data in terms of sky sampling and with matching time domain noise characteristics, to make statistical arguments about the likelihood of the noise observed in the actual data nulls.<br />
In general null tests are performed to highlight possible issues in the data related to instrumental systematic effecst not properly accounted for within the processing pipeline, or related to known changes in the operational conditions (e.g., switch-over of the sorption coolers), or related to intrinsic instrument properties coupled with the sky signal, such as stray light contamination.<br />
Such null-tests can be performed by using data on different time scales ranging from 1 minute to 1 year of observations, at different unit levels (radiometer, horn, horn-pair), within frequency and cross-frequency, both in total intensity, and, when applicable, in polarization.<br />
<br />
=== Sample Null Maps ===<br />
<br />
[[File:Fig_13.png|thumb|center|900px]]<br />
<br />
This figure shows difefrences between 2018 and 1015 frequenncy maps in <i>I</i>, <i>Q</i> and <i>U</i>. Large scale differences between the two set of maps are mainly due to changes in the calibration procedure.<br />
<br />
[[File:Fig_14.png|thumb|center|900px]]<br />
<br />
In this figure we consider the set of odd-even survey differences combining all eight sky surveys covered by LFI. These survey combinations optimize the signal-to-noise ratio and highlight<br />
large-scale structures. The nine maps on the left show odd-even survey dfferences for the 2015 release, while the nine maps on the right show the same for the 2018 release. The 2015 data show large residuals in <i>I</i> at 30 and 44 GHz that bias the difference away from zero. This effect is considerably reduced in the 2018 release, as expected from the improvements in the calibration process. The <i>I</i> map at 70 GHz also shows a significant improvement. In the polarization maps, there is a general reduction in the amplitude of structures close to the Galactic plane.<br />
<br />
[[File:Fig_15.png|thumb|center|400px]]<br />
<br />
Finally here we shows pseudo-angular power spectra from the oddeven survey dfferences. There is great improvement in 2018 in removing largescale structures at 30 GHz in <i>TT</i>, <i>EE</i>, and somewhat in <i>BB</i>, and also in <i>TT</i> at 44 GHz.<br />
<br />
<br />
===Intra-frequency consistency check===<br />
We have tested the consistency between 30, 44, and 70GHz maps by comparing the power spectra in the multipole range around the first acoustic peak. In order to do so, we have removed the estimated contribution from unresolved point source from the spectra. We have then built scatter plots for the three frequency pairs, i.e., 70GHz versus 30 GHz, 70GHz versus 44GHz, and 44GHz versus 30GHz, and performed a linear fit, accounting for errors on both axes.<br />
The results reported in Fig. 6 show that the three power spectra are consistent within the errors. Moreover, note that the current error budget does not account for foreground removal, calibration, and window function uncertainties. Hence, the observed agreement between spectra at different frequencies can be considered to be even more satisfactory.<br />
<br />
[[File:LFI_70vs44_DX11D_maskTCS070vs060_a.jpg|thumb|center|400px|]][[File:LFI_70vs30_DX11D_maskTCS070vs040_a.jpg|thumb|center|400px|]][[File:LFI_44vs30_DX11D_maskTCS060vs040_a.jpg|thumb|center|400px|'''Figure 6: Consistency between spectral estimates at different frequencies. From top to bottom: 70GHz versus 44 GHz; 70GHz versus 30 GHz; and 44GHz versus 30 GHz. Solid red lines are the best fit of the linear regressions, whose angular coefficients &alpha; are consistent with unity within the errors.''']]<br />
<br />
===70 GHz internal consistency check===<br />
We use the Hausman test {{BibCite|polenta_CrossSpectra}} to assess the consistency of auto- and cross-spectral estimates at 70 GHz. We specifically define the statistic:<br />
<br />
:<math><br />
H_{\ell}=\left(\hat{C_{\ell}}-\tilde{C_{\ell}}\right)/\sqrt{{\rm Var}\left\{ \hat{C_{\ell}}-\tilde{C_{\ell}}\right\} },<br />
</math><br />
<br />
where <math>\hat{C_{\ell}}</math> and <math>\tilde{C_{\ell}}</math> represent auto- and<br />
cross-spectra, respectively. In order to combine information from different multipoles into a single quantity, we define<br />
<br />
:<math><br />
B_{L}(r)=\frac{1}{\sqrt{L}}\sum_{\ell=2}^{[Lr]}H_{\ell},r\in\left[0,1\right],<br />
</math><br />
<br />
where square brackets denote the integer part. The distribution of <i>B<sub>L</sub></i>(<i>r</i>)<br />
converges (in a functional sense) to a Brownian motion process, which can be studied through the statistics<br />
<i>s</i><sub>1</sub>=sup<sub><i>r</i></sub><i>B<sub>L</sub></i>(<i>r</i>),<br />
<i>s</i><sub>2</sub>=sup<sub><i>r</i></sub>|<i>B<sub>L</sub></i>(<i>r</i>)|, and<br />
<i>s</i><sub>3</sub>=&#8747;<sub>0</sub><sup>1</sup><i>B<sub>L</sub></i><sup>2</sup>(<i>r</i>)dr. Using the "FFP7" simulations,<br />
we derive empirical distributions for all the three test statistics and compare with results obtained from Planck data<br />
(see Fig. 7). We find that the Hausman test shows no statistically significant inconsistencies between the two spectral<br />
estimates.<br />
<br />
[[File:cons2.jpg|thumb|center|800px|'''Figure 7: From left to right, the empirical<br />
distribution (estimated via FFP7) of the <i>s</i><sub>1</sub>, <i>s</i><sub>2</sub>, and <i>s</i><sub>3</sub><br />
statistics (see text). The vertical line represents 70GHz data.''']]<br />
<br />
As a further test, we have estimated the temperature power spectrum for each of three horn-pair maps, and have compared the<br />
results with the spectrum obtained from all 12 radiometers shown above. In Fig. 8 we plot the<br />
difference between the horn-pair and the combined power spectra.<br />
Again, the error bars have been estimated from the FFP7 simulated data set. A &chi;<sup>2</sup> analysis of the residual shows that they are compatible with the null hypothesis, confirming the<br />
strong consistency of the estimates.<br />
<br />
[[File:cons3.jpg|thumb|center|500px|'''Figure 8: Residuals between the auto-power spectra of the horn-pair maps and the power spectrum of the full 70GHz frequency map. Error bars here are derived from FFP7 simulations.''']]<br />
<br />
<!--<br />
== Data Release Results ==<br />
<br />
=== Impact on cosmology ===<br />
--><br />
<br />
== References ==<br />
<br />
<References /><br />
<br />
<br />
[[Category:LFI data processing|006]]</div>Azaccheihttps://wiki.cosmos.esa.int/planck-legacy-archive/index.php?title=LFI-Validation&diff=14081LFI-Validation2018-07-06T10:57:18Z<p>Azacchei: </p>
<hr />
<div>{{DISPLAYTITLE:Overall internal validation}}<br />
== Overview ==<br />
Data validation is critical at each step of the analysis pipeline. Much of the LFI data validation is based on null tests. Here we present some examples from the current release, with comments on relevant time scales and sensitivity to various systematics. In the 2018 release in addition we perform many test to verify the differences between this and previous release (see {{PlanckPapers|planck2016-l02}}).<br />
<br />
== Null tests approach ==<br />
Null tests at map level are performed routinely, whenever changes are made to the mapmaking pipeline. These include differences at survey, year, 2-year, half- mission and half-ring levels, for single detectors, horns, horn pairs and full frequency complements. Where possible, map differences are generated in <i>I</i>, <i>Q</i> and <i>U</i>. <br />
For this release, we use the Full Focal Plane 10 (FFP10) simulations for comparison. We can use FFP10 noise simulations, identical to the data in terms of sky sampling and with matching time domain noise characteristics, to make statistical arguments about the likelihood of the noise observed in the actual data nulls.<br />
In general null tests are performed to highlight possible issues in the data related to instrumental systematic effecst not properly accounted for within the processing pipeline, or related to known changes in the operational conditions (e.g., switch-over of the sorption coolers), or related to intrinsic instrument properties coupled with the sky signal, such as stray light contamination.<br />
Such null-tests can be performed by using data on different time scales ranging from 1 minute to 1 year of observations, at different unit levels (radiometer, horn, horn-pair), within frequency and cross-frequency, both in total intensity, and, when applicable, in polarization.<br />
<br />
=== Sample Null Maps ===<br />
<br />
[[File:Fig_13.png|thumb|center|900px]]<br />
<br />
This figure shows difefrences between 2018 and 1015 frequenncy maps in <i>I</i>, <i>Q</i> and <i>U</i>. Large scale differences between the two set of maps are mainly due to changes in the calibration procedure.<br />
<br />
[[File:Fig_14.png|thumb|center|900px]]<br />
<br />
In this figure we consider the set of odd-even survey differences combining all eight sky surveys covered by LFI. These survey combinations optimize the signal-to-noise ratio and highlight<br />
large-scale structures. The nine maps on the left show odd-even survey dfferences for the 2015 release, while the nine maps on the right show the same for the 2018 release. The 2015 data show large residuals in <i>I</i> at 30 and 44 GHz that bias the difference away from zero. This effect is considerably reduced in the 2018 release, as expected from the improvements in the calibration process. The <i>I</i> map at 70 GHz also shows a significant improvement. In the polarization maps, there is a general reduction in the amplitude of structures close to the Galactic plane.<br />
<br />
[[File:Fig_15.png|thumb|center|400px]]<br />
<br />
Finally here we shows pseudo-angular power spectra from the oddeven survey dfferences. There is great improvement in 2018 in removing largescale structures at 30 GHz in <i>TT</i>, <i>EE</i>, and somewhat in <i>BB</i>, and also in <i>TT</i> at 44 GHz.<br />
<br />
===Statistical Analyses===<br />
The next level of data compression is to use the angular power spectra of the null tests, and to compare to simulations in a statistically robust way. We use two different approaches. <br />
In the first we compare pseudo-spectra of the null maps to the half-ring spectra, which are the most "free" of anticipated systmatics. <br />
In the second, we use noise Monte Carlos from the FFP8 simulations, where we run the mapmaking identically to the real data, over data sets with identical sampling to the real data but consisting of noise only generated to match the per-detector LFI noise model. <br />
<br />
Here we show examples comparing the pseudo-spectra of a set of 100 Monte Carlos to the real data. We mask both data and simlations to concentrate on residuals impacting CMB analyses away from the Galactic plane.<br />
<br />
[[File:null_cl_ffp8_070yr1+yr3-yr2+yr4_TT_lin_88mm.png|thumb|center|400px]]<br />
[[File:null_cl_ffp8_070yr1+yr3-yr2+yr4_TT_log88mm.png|thumb|center|400px|'''Figure 2: Pseudo-spectrum comparison (70GHz <i>TT</i>) of 2-year data difference (Year(1+3)-Year(2+4) in green) to the FFP8 simulation distribution (blue error bars).''']]<br />
<br />
[[File:null_cl_ffp8_070yr1+yr3-yr2+yr4_EE_lin_88mm.png|thumb|center|400px]]<br />
[[File:null_cl_ffp8_070yr1+yr3-yr2+yr4_EE_log88mm.png|thumb|center|400px|'''Figure 3: Pseudo-spectrum comparison (70GHz <i>EE</i>) of 2-year data difference (Year(1+3)-Year(2+4) in green) to the FFP8 simulation distribution (blue error bars).''']]<br />
<br />
[[File:null_cl_ffp8_070yr1+yr3-yr2+yr4_BB_lin_88mm.png|thumb|center|400px]]<br />
[[File:null_cl_ffp8_070yr1+yr3-yr2+yr4_BB_log88mm.png|thumb|center|400px|'''Figure 4: Pseudo-spectrum comparison(70GHz <i>BB</i>) of 2-year data difference (Year(1+3)-Year(2+4) in green) to the FFP8 simulation distribution (blue error bars).''']]<br />
<br />
Finally, we can look at the distribution of noise power from the Monte Carlos "&#8467; by &#8467;" and check where the real data fall in that distribution, to see if it is consistent with noise alone.<br />
<br />
[[File:ffp8_dist_070full-survey_1survey_3_TT88mm_nt.png|350px|]]<br />
[[File:ffp8_dist_070full-survey_1survey_3_EE88mm_nt.png|350px|]]<br />
[[File:ffp8_dist_070full-survey_1survey_3_BB88mm_nt.png|350px|]]<br />
<br />
'''<small>Figure 5: Sample 70GHz null test in comparison with FFP8 null distribution for multipoles from 2 to 4. From left to right we show <i>TT</i>, <i>EE</i>, <i>BB</i>. In this case, the null test is the full mission map - (Survey 1+Survey 3). We report the probability to exceed (PTE) values for the data relative to the FFP8 noise-only distributions. All values for this example are very reasonable, suggesting that our noise model captures the important features of the data even at low multipoles.</small>'''<br />
<br />
==Consistency checks ==<br />
<br />
All the details of consistency tests performed can be found in {{PlanckPapers|planck2013-p02}} and {{PlanckPapers|planck2014-a03||Planck-2015-A03}}. <br />
<br />
===Intra-frequency consistency check===<br />
We have tested the consistency between 30, 44, and 70GHz maps by comparing the power spectra in the multipole range around the first acoustic peak. In order to do so, we have removed the estimated contribution from unresolved point source from the spectra. We have then built scatter plots for the three frequency pairs, i.e., 70GHz versus 30 GHz, 70GHz versus 44GHz, and 44GHz versus 30GHz, and performed a linear fit, accounting for errors on both axes.<br />
The results reported in Fig. 6 show that the three power spectra are consistent within the errors. Moreover, note that the current error budget does not account for foreground removal, calibration, and window function uncertainties. Hence, the observed agreement between spectra at different frequencies can be considered to be even more satisfactory.<br />
<br />
[[File:LFI_70vs44_DX11D_maskTCS070vs060_a.jpg|thumb|center|400px|]][[File:LFI_70vs30_DX11D_maskTCS070vs040_a.jpg|thumb|center|400px|]][[File:LFI_44vs30_DX11D_maskTCS060vs040_a.jpg|thumb|center|400px|'''Figure 6: Consistency between spectral estimates at different frequencies. From top to bottom: 70GHz versus 44 GHz; 70GHz versus 30 GHz; and 44GHz versus 30 GHz. Solid red lines are the best fit of the linear regressions, whose angular coefficients &alpha; are consistent with unity within the errors.''']]<br />
<br />
===70 GHz internal consistency check===<br />
We use the Hausman test {{BibCite|polenta_CrossSpectra}} to assess the consistency of auto- and cross-spectral estimates at 70 GHz. We specifically define the statistic:<br />
<br />
:<math><br />
H_{\ell}=\left(\hat{C_{\ell}}-\tilde{C_{\ell}}\right)/\sqrt{{\rm Var}\left\{ \hat{C_{\ell}}-\tilde{C_{\ell}}\right\} },<br />
</math><br />
<br />
where <math>\hat{C_{\ell}}</math> and <math>\tilde{C_{\ell}}</math> represent auto- and<br />
cross-spectra, respectively. In order to combine information from different multipoles into a single quantity, we define<br />
<br />
:<math><br />
B_{L}(r)=\frac{1}{\sqrt{L}}\sum_{\ell=2}^{[Lr]}H_{\ell},r\in\left[0,1\right],<br />
</math><br />
<br />
where square brackets denote the integer part. The distribution of <i>B<sub>L</sub></i>(<i>r</i>)<br />
converges (in a functional sense) to a Brownian motion process, which can be studied through the statistics<br />
<i>s</i><sub>1</sub>=sup<sub><i>r</i></sub><i>B<sub>L</sub></i>(<i>r</i>),<br />
<i>s</i><sub>2</sub>=sup<sub><i>r</i></sub>|<i>B<sub>L</sub></i>(<i>r</i>)|, and<br />
<i>s</i><sub>3</sub>=&#8747;<sub>0</sub><sup>1</sup><i>B<sub>L</sub></i><sup>2</sup>(<i>r</i>)dr. Using the "FFP7" simulations,<br />
we derive empirical distributions for all the three test statistics and compare with results obtained from Planck data<br />
(see Fig. 7). We find that the Hausman test shows no statistically significant inconsistencies between the two spectral<br />
estimates.<br />
<br />
[[File:cons2.jpg|thumb|center|800px|'''Figure 7: From left to right, the empirical<br />
distribution (estimated via FFP7) of the <i>s</i><sub>1</sub>, <i>s</i><sub>2</sub>, and <i>s</i><sub>3</sub><br />
statistics (see text). The vertical line represents 70GHz data.''']]<br />
<br />
As a further test, we have estimated the temperature power spectrum for each of three horn-pair maps, and have compared the<br />
results with the spectrum obtained from all 12 radiometers shown above. In Fig. 8 we plot the<br />
difference between the horn-pair and the combined power spectra.<br />
Again, the error bars have been estimated from the FFP7 simulated data set. A &chi;<sup>2</sup> analysis of the residual shows that they are compatible with the null hypothesis, confirming the<br />
strong consistency of the estimates.<br />
<br />
[[File:cons3.jpg|thumb|center|500px|'''Figure 8: Residuals between the auto-power spectra of the horn-pair maps and the power spectrum of the full 70GHz frequency map. Error bars here are derived from FFP7 simulations.''']]<br />
<br />
<!--<br />
== Data Release Results ==<br />
<br />
=== Impact on cosmology ===<br />
--><br />
<br />
== References ==<br />
<br />
<References /><br />
<br />
<br />
[[Category:LFI data processing|006]]</div>Azaccheihttps://wiki.cosmos.esa.int/planck-legacy-archive/index.php?title=LFI-Validation&diff=14080LFI-Validation2018-07-06T10:56:34Z<p>Azacchei: </p>
<hr />
<div>{{DISPLAYTITLE:Overall internal validation}}<br />
== Overview ==<br />
Data validation is critical at each step of the analysis pipeline. Much of the LFI data validation is based on null tests. Here we present some examples from the current release, with comments on relevant time scales and sensitivity to various systematics. In the 2018 release in addition we perform many test to verify the differences between this and previous release (see {{PlanckPapers|planck2016-l02}}).<br />
<br />
== Null tests approach ==<br />
Null tests at map level are performed routinely, whenever changes are made to the mapmaking pipeline. These include differences at survey, year, 2-year, half- mission and half-ring levels, for single detectors, horns, horn pairs and full frequency complements. Where possible, map differences are generated in <i>I</i>, <i>Q</i> and <i>U</i>. <br />
For this release, we use the Full Focal Plane 10 (FFP10) simulations for comparison. We can use FFP10 noise simulations, identical to the data in terms of sky sampling and with matching time domain noise characteristics, to make statistical arguments about the likelihood of the noise observed in the actual data nulls.<br />
In general null tests are performed to highlight possible issues in the data related to instrumental systematic effecst not properly accounted for within the processing pipeline, or related to known changes in the operational conditions (e.g., switch-over of the sorption coolers), or related to intrinsic instrument properties coupled with the sky signal, such as stray light contamination.<br />
Such null-tests can be performed by using data on different time scales ranging from 1 minute to 1 year of observations, at different unit levels (radiometer, horn, horn-pair), within frequency and cross-frequency, both in total intensity, and, when applicable, in polarization.<br />
<br />
=== Sample Null Maps ===<br />
<br />
[[File:Fig_13.png|thumb|center|900px]]<br />
<br />
This figure shows difefrences between 2018 and 1015 frequenncy maps in <i>I</i>, <i>Q</i> and <i>U</i>. Large scale differences between the two set of maps are mainly due to changes in the calibration procedure.<br />
<br />
[[File:Fig_14.png|thumb|center|900px]]<br />
<br />
In this figure we consider the set of odd-even survey differences combining all eight sky surveys covered by LFI. These survey combinations optimize the signal-to-noise ratio and highlight<br />
large-scale structures. The nine maps on the left show odd-even survey dfferences for the 2015 release, while the nine maps on the right show the same for the 2018 release. The 2015 data show large residuals in <i>I</i> at 30 and 44 GHz that bias the difference away from zero. This effect is considerably reduced in the 2018 release, as expected from the improvements in the calibration process. The <i>I</i> map at 70 GHz also shows a significant improvement. In the polarization maps, there is a general reduction in the amplitude of structures close to the Galactic plane.<br />
<br />
[[File:Fig_15.png|thumb|center|900px]]<br />
<br />
Finally here we shows pseudo-angular power spectra from the oddeven survey dfferences. There is great improvement in 2018 in removing largescale structures at 30 GHz in <i>TT</i>, <i>EE</i>, and somewhat in <i>BB</i>, and also in <i>TT</i> at 44 GHz.<br />
<br />
===Statistical Analyses===<br />
The next level of data compression is to use the angular power spectra of the null tests, and to compare to simulations in a statistically robust way. We use two different approaches. <br />
In the first we compare pseudo-spectra of the null maps to the half-ring spectra, which are the most "free" of anticipated systmatics. <br />
In the second, we use noise Monte Carlos from the FFP8 simulations, where we run the mapmaking identically to the real data, over data sets with identical sampling to the real data but consisting of noise only generated to match the per-detector LFI noise model. <br />
<br />
Here we show examples comparing the pseudo-spectra of a set of 100 Monte Carlos to the real data. We mask both data and simlations to concentrate on residuals impacting CMB analyses away from the Galactic plane.<br />
<br />
[[File:null_cl_ffp8_070yr1+yr3-yr2+yr4_TT_lin_88mm.png|thumb|center|400px]]<br />
[[File:null_cl_ffp8_070yr1+yr3-yr2+yr4_TT_log88mm.png|thumb|center|400px|'''Figure 2: Pseudo-spectrum comparison (70GHz <i>TT</i>) of 2-year data difference (Year(1+3)-Year(2+4) in green) to the FFP8 simulation distribution (blue error bars).''']]<br />
<br />
[[File:null_cl_ffp8_070yr1+yr3-yr2+yr4_EE_lin_88mm.png|thumb|center|400px]]<br />
[[File:null_cl_ffp8_070yr1+yr3-yr2+yr4_EE_log88mm.png|thumb|center|400px|'''Figure 3: Pseudo-spectrum comparison (70GHz <i>EE</i>) of 2-year data difference (Year(1+3)-Year(2+4) in green) to the FFP8 simulation distribution (blue error bars).''']]<br />
<br />
[[File:null_cl_ffp8_070yr1+yr3-yr2+yr4_BB_lin_88mm.png|thumb|center|400px]]<br />
[[File:null_cl_ffp8_070yr1+yr3-yr2+yr4_BB_log88mm.png|thumb|center|400px|'''Figure 4: Pseudo-spectrum comparison(70GHz <i>BB</i>) of 2-year data difference (Year(1+3)-Year(2+4) in green) to the FFP8 simulation distribution (blue error bars).''']]<br />
<br />
Finally, we can look at the distribution of noise power from the Monte Carlos "&#8467; by &#8467;" and check where the real data fall in that distribution, to see if it is consistent with noise alone.<br />
<br />
[[File:ffp8_dist_070full-survey_1survey_3_TT88mm_nt.png|350px|]]<br />
[[File:ffp8_dist_070full-survey_1survey_3_EE88mm_nt.png|350px|]]<br />
[[File:ffp8_dist_070full-survey_1survey_3_BB88mm_nt.png|350px|]]<br />
<br />
'''<small>Figure 5: Sample 70GHz null test in comparison with FFP8 null distribution for multipoles from 2 to 4. From left to right we show <i>TT</i>, <i>EE</i>, <i>BB</i>. In this case, the null test is the full mission map - (Survey 1+Survey 3). We report the probability to exceed (PTE) values for the data relative to the FFP8 noise-only distributions. All values for this example are very reasonable, suggesting that our noise model captures the important features of the data even at low multipoles.</small>'''<br />
<br />
==Consistency checks ==<br />
<br />
All the details of consistency tests performed can be found in {{PlanckPapers|planck2013-p02}} and {{PlanckPapers|planck2014-a03||Planck-2015-A03}}. <br />
<br />
===Intra-frequency consistency check===<br />
We have tested the consistency between 30, 44, and 70GHz maps by comparing the power spectra in the multipole range around the first acoustic peak. In order to do so, we have removed the estimated contribution from unresolved point source from the spectra. We have then built scatter plots for the three frequency pairs, i.e., 70GHz versus 30 GHz, 70GHz versus 44GHz, and 44GHz versus 30GHz, and performed a linear fit, accounting for errors on both axes.<br />
The results reported in Fig. 6 show that the three power spectra are consistent within the errors. Moreover, note that the current error budget does not account for foreground removal, calibration, and window function uncertainties. Hence, the observed agreement between spectra at different frequencies can be considered to be even more satisfactory.<br />
<br />
[[File:LFI_70vs44_DX11D_maskTCS070vs060_a.jpg|thumb|center|400px|]][[File:LFI_70vs30_DX11D_maskTCS070vs040_a.jpg|thumb|center|400px|]][[File:LFI_44vs30_DX11D_maskTCS060vs040_a.jpg|thumb|center|400px|'''Figure 6: Consistency between spectral estimates at different frequencies. From top to bottom: 70GHz versus 44 GHz; 70GHz versus 30 GHz; and 44GHz versus 30 GHz. Solid red lines are the best fit of the linear regressions, whose angular coefficients &alpha; are consistent with unity within the errors.''']]<br />
<br />
===70 GHz internal consistency check===<br />
We use the Hausman test {{BibCite|polenta_CrossSpectra}} to assess the consistency of auto- and cross-spectral estimates at 70 GHz. We specifically define the statistic:<br />
<br />
:<math><br />
H_{\ell}=\left(\hat{C_{\ell}}-\tilde{C_{\ell}}\right)/\sqrt{{\rm Var}\left\{ \hat{C_{\ell}}-\tilde{C_{\ell}}\right\} },<br />
</math><br />
<br />
where <math>\hat{C_{\ell}}</math> and <math>\tilde{C_{\ell}}</math> represent auto- and<br />
cross-spectra, respectively. In order to combine information from different multipoles into a single quantity, we define<br />
<br />
:<math><br />
B_{L}(r)=\frac{1}{\sqrt{L}}\sum_{\ell=2}^{[Lr]}H_{\ell},r\in\left[0,1\right],<br />
</math><br />
<br />
where square brackets denote the integer part. The distribution of <i>B<sub>L</sub></i>(<i>r</i>)<br />
converges (in a functional sense) to a Brownian motion process, which can be studied through the statistics<br />
<i>s</i><sub>1</sub>=sup<sub><i>r</i></sub><i>B<sub>L</sub></i>(<i>r</i>),<br />
<i>s</i><sub>2</sub>=sup<sub><i>r</i></sub>|<i>B<sub>L</sub></i>(<i>r</i>)|, and<br />
<i>s</i><sub>3</sub>=&#8747;<sub>0</sub><sup>1</sup><i>B<sub>L</sub></i><sup>2</sup>(<i>r</i>)dr. Using the "FFP7" simulations,<br />
we derive empirical distributions for all the three test statistics and compare with results obtained from Planck data<br />
(see Fig. 7). We find that the Hausman test shows no statistically significant inconsistencies between the two spectral<br />
estimates.<br />
<br />
[[File:cons2.jpg|thumb|center|800px|'''Figure 7: From left to right, the empirical<br />
distribution (estimated via FFP7) of the <i>s</i><sub>1</sub>, <i>s</i><sub>2</sub>, and <i>s</i><sub>3</sub><br />
statistics (see text). The vertical line represents 70GHz data.''']]<br />
<br />
As a further test, we have estimated the temperature power spectrum for each of three horn-pair maps, and have compared the<br />
results with the spectrum obtained from all 12 radiometers shown above. In Fig. 8 we plot the<br />
difference between the horn-pair and the combined power spectra.<br />
Again, the error bars have been estimated from the FFP7 simulated data set. A &chi;<sup>2</sup> analysis of the residual shows that they are compatible with the null hypothesis, confirming the<br />
strong consistency of the estimates.<br />
<br />
[[File:cons3.jpg|thumb|center|500px|'''Figure 8: Residuals between the auto-power spectra of the horn-pair maps and the power spectrum of the full 70GHz frequency map. Error bars here are derived from FFP7 simulations.''']]<br />
<br />
<!--<br />
== Data Release Results ==<br />
<br />
=== Impact on cosmology ===<br />
--><br />
<br />
== References ==<br />
<br />
<References /><br />
<br />
<br />
[[Category:LFI data processing|006]]</div>Azaccheihttps://wiki.cosmos.esa.int/planck-legacy-archive/index.php?title=LFI-Validation&diff=14078LFI-Validation2018-07-06T10:44:23Z<p>Azacchei: </p>
<hr />
<div>{{DISPLAYTITLE:Overall internal validation}}<br />
== Overview ==<br />
Data validation is critical at each step of the analysis pipeline. Much of the LFI data validation is based on null tests. Here we present some examples from the current release, with comments on relevant time scales and sensitivity to various systematics. In the 2018 release in addition we perform many test to verify the differences between this and previous release (see {{PlanckPapers|planck2016-l02}}).<br />
<br />
== Null tests approach ==<br />
Null tests at map level are performed routinely, whenever changes are made to the mapmaking pipeline. These include differences at survey, year, 2-year, half- mission and half-ring levels, for single detectors, horns, horn pairs and full frequency complements. Where possible, map differences are generated in <i>I</i>, <i>Q</i> and <i>U</i>. <br />
For this release, we use the Full Focal Plane 10 (FFP10) simulations for comparison. We can use FFP10 noise simulations, identical to the data in terms of sky sampling and with matching time domain noise characteristics, to make statistical arguments about the likelihood of the noise observed in the actual data nulls.<br />
In general null tests are performed to highlight possible issues in the data related to instrumental systematic effecst not properly accounted for within the processing pipeline, or related to known changes in the operational conditions (e.g., switch-over of the sorption coolers), or related to intrinsic instrument properties coupled with the sky signal, such as stray light contamination.<br />
Such null-tests can be performed by using data on different time scales ranging from 1 minute to 1 year of observations, at different unit levels (radiometer, horn, horn-pair), within frequency and cross-frequency, both in total intensity, and, when applicable, in polarization.<br />
<br />
=== Sample Null Maps ===<br />
<br />
[[File:Fig_13.png|thumb|center|900px]]<br />
<br />
<br />
<br />
[[File:Fig_14.png|thumb|center|900px]]<br />
<br />
<br />
Three things are worth pointing out generally about these maps.<br />
Firstly, there are no obvious "features" standing out at this resolution and noise level. Earlier versions of the data processing, where there were errors in calibration for instance, would show scan-correlated structures at much larger amplitude.<br />
Secondly, the half-ring difference maps and the 2-year combination difference maps give a very similar overall impression. This is a very good sign, as these two types of null map cover very different time scales (1 hour to 2 years).<br />
Thirdly, it is impossible to know how "good" the test is just by looking at the map. There is clearly noise, but determining if it is consistent with the noise model of the instrument, and further, if it will bias the scientific results, requires more analysis.<br />
<br />
===Statistical Analyses===<br />
The next level of data compression is to use the angular power spectra of the null tests, and to compare to simulations in a statistically robust way. We use two different approaches. <br />
In the first we compare pseudo-spectra of the null maps to the half-ring spectra, which are the most "free" of anticipated systmatics. <br />
In the second, we use noise Monte Carlos from the FFP8 simulations, where we run the mapmaking identically to the real data, over data sets with identical sampling to the real data but consisting of noise only generated to match the per-detector LFI noise model. <br />
<br />
Here we show examples comparing the pseudo-spectra of a set of 100 Monte Carlos to the real data. We mask both data and simlations to concentrate on residuals impacting CMB analyses away from the Galactic plane.<br />
<br />
[[File:null_cl_ffp8_070yr1+yr3-yr2+yr4_TT_lin_88mm.png|thumb|center|400px]]<br />
[[File:null_cl_ffp8_070yr1+yr3-yr2+yr4_TT_log88mm.png|thumb|center|400px|'''Figure 2: Pseudo-spectrum comparison (70GHz <i>TT</i>) of 2-year data difference (Year(1+3)-Year(2+4) in green) to the FFP8 simulation distribution (blue error bars).''']]<br />
<br />
[[File:null_cl_ffp8_070yr1+yr3-yr2+yr4_EE_lin_88mm.png|thumb|center|400px]]<br />
[[File:null_cl_ffp8_070yr1+yr3-yr2+yr4_EE_log88mm.png|thumb|center|400px|'''Figure 3: Pseudo-spectrum comparison (70GHz <i>EE</i>) of 2-year data difference (Year(1+3)-Year(2+4) in green) to the FFP8 simulation distribution (blue error bars).''']]<br />
<br />
[[File:null_cl_ffp8_070yr1+yr3-yr2+yr4_BB_lin_88mm.png|thumb|center|400px]]<br />
[[File:null_cl_ffp8_070yr1+yr3-yr2+yr4_BB_log88mm.png|thumb|center|400px|'''Figure 4: Pseudo-spectrum comparison(70GHz <i>BB</i>) of 2-year data difference (Year(1+3)-Year(2+4) in green) to the FFP8 simulation distribution (blue error bars).''']]<br />
<br />
Finally, we can look at the distribution of noise power from the Monte Carlos "&#8467; by &#8467;" and check where the real data fall in that distribution, to see if it is consistent with noise alone.<br />
<br />
[[File:ffp8_dist_070full-survey_1survey_3_TT88mm_nt.png|350px|]]<br />
[[File:ffp8_dist_070full-survey_1survey_3_EE88mm_nt.png|350px|]]<br />
[[File:ffp8_dist_070full-survey_1survey_3_BB88mm_nt.png|350px|]]<br />
<br />
'''<small>Figure 5: Sample 70GHz null test in comparison with FFP8 null distribution for multipoles from 2 to 4. From left to right we show <i>TT</i>, <i>EE</i>, <i>BB</i>. In this case, the null test is the full mission map - (Survey 1+Survey 3). We report the probability to exceed (PTE) values for the data relative to the FFP8 noise-only distributions. All values for this example are very reasonable, suggesting that our noise model captures the important features of the data even at low multipoles.</small>'''<br />
<br />
==Consistency checks ==<br />
<br />
All the details of consistency tests performed can be found in {{PlanckPapers|planck2013-p02}} and {{PlanckPapers|planck2014-a03||Planck-2015-A03}}. <br />
<br />
===Intra-frequency consistency check===<br />
We have tested the consistency between 30, 44, and 70GHz maps by comparing the power spectra in the multipole range around the first acoustic peak. In order to do so, we have removed the estimated contribution from unresolved point source from the spectra. We have then built scatter plots for the three frequency pairs, i.e., 70GHz versus 30 GHz, 70GHz versus 44GHz, and 44GHz versus 30GHz, and performed a linear fit, accounting for errors on both axes.<br />
The results reported in Fig. 6 show that the three power spectra are consistent within the errors. Moreover, note that the current error budget does not account for foreground removal, calibration, and window function uncertainties. Hence, the observed agreement between spectra at different frequencies can be considered to be even more satisfactory.<br />
<br />
[[File:LFI_70vs44_DX11D_maskTCS070vs060_a.jpg|thumb|center|400px|]][[File:LFI_70vs30_DX11D_maskTCS070vs040_a.jpg|thumb|center|400px|]][[File:LFI_44vs30_DX11D_maskTCS060vs040_a.jpg|thumb|center|400px|'''Figure 6: Consistency between spectral estimates at different frequencies. From top to bottom: 70GHz versus 44 GHz; 70GHz versus 30 GHz; and 44GHz versus 30 GHz. Solid red lines are the best fit of the linear regressions, whose angular coefficients &alpha; are consistent with unity within the errors.''']]<br />
<br />
===70 GHz internal consistency check===<br />
We use the Hausman test {{BibCite|polenta_CrossSpectra}} to assess the consistency of auto- and cross-spectral estimates at 70 GHz. We specifically define the statistic:<br />
<br />
:<math><br />
H_{\ell}=\left(\hat{C_{\ell}}-\tilde{C_{\ell}}\right)/\sqrt{{\rm Var}\left\{ \hat{C_{\ell}}-\tilde{C_{\ell}}\right\} },<br />
</math><br />
<br />
where <math>\hat{C_{\ell}}</math> and <math>\tilde{C_{\ell}}</math> represent auto- and<br />
cross-spectra, respectively. In order to combine information from different multipoles into a single quantity, we define<br />
<br />
:<math><br />
B_{L}(r)=\frac{1}{\sqrt{L}}\sum_{\ell=2}^{[Lr]}H_{\ell},r\in\left[0,1\right],<br />
</math><br />
<br />
where square brackets denote the integer part. The distribution of <i>B<sub>L</sub></i>(<i>r</i>)<br />
converges (in a functional sense) to a Brownian motion process, which can be studied through the statistics<br />
<i>s</i><sub>1</sub>=sup<sub><i>r</i></sub><i>B<sub>L</sub></i>(<i>r</i>),<br />
<i>s</i><sub>2</sub>=sup<sub><i>r</i></sub>|<i>B<sub>L</sub></i>(<i>r</i>)|, and<br />
<i>s</i><sub>3</sub>=&#8747;<sub>0</sub><sup>1</sup><i>B<sub>L</sub></i><sup>2</sup>(<i>r</i>)dr. Using the "FFP7" simulations,<br />
we derive empirical distributions for all the three test statistics and compare with results obtained from Planck data<br />
(see Fig. 7). We find that the Hausman test shows no statistically significant inconsistencies between the two spectral<br />
estimates.<br />
<br />
[[File:cons2.jpg|thumb|center|800px|'''Figure 7: From left to right, the empirical<br />
distribution (estimated via FFP7) of the <i>s</i><sub>1</sub>, <i>s</i><sub>2</sub>, and <i>s</i><sub>3</sub><br />
statistics (see text). The vertical line represents 70GHz data.''']]<br />
<br />
As a further test, we have estimated the temperature power spectrum for each of three horn-pair maps, and have compared the<br />
results with the spectrum obtained from all 12 radiometers shown above. In Fig. 8 we plot the<br />
difference between the horn-pair and the combined power spectra.<br />
Again, the error bars have been estimated from the FFP7 simulated data set. A &chi;<sup>2</sup> analysis of the residual shows that they are compatible with the null hypothesis, confirming the<br />
strong consistency of the estimates.<br />
<br />
[[File:cons3.jpg|thumb|center|500px|'''Figure 8: Residuals between the auto-power spectra of the horn-pair maps and the power spectrum of the full 70GHz frequency map. Error bars here are derived from FFP7 simulations.''']]<br />
<br />
<!--<br />
== Data Release Results ==<br />
<br />
=== Impact on cosmology ===<br />
--><br />
<br />
== References ==<br />
<br />
<References /><br />
<br />
<br />
[[Category:LFI data processing|006]]</div>Azaccheihttps://wiki.cosmos.esa.int/planck-legacy-archive/index.php?title=File:Fig_21.png&diff=14075File:Fig 21.png2018-07-06T10:29:50Z<p>Azacchei: </p>
<hr />
<div></div>Azaccheihttps://wiki.cosmos.esa.int/planck-legacy-archive/index.php?title=File:Fig_15.png&diff=14074File:Fig 15.png2018-07-06T10:29:32Z<p>Azacchei: </p>
<hr />
<div></div>Azaccheihttps://wiki.cosmos.esa.int/planck-legacy-archive/index.php?title=File:Fig_14.png&diff=14073File:Fig 14.png2018-07-06T10:29:15Z<p>Azacchei: </p>
<hr />
<div></div>Azaccheihttps://wiki.cosmos.esa.int/planck-legacy-archive/index.php?title=File:Fig_13.png&diff=14071File:Fig 13.png2018-07-06T10:28:55Z<p>Azacchei: </p>
<hr />
<div></div>Azaccheihttps://wiki.cosmos.esa.int/planck-legacy-archive/index.php?title=LFI-Validation&diff=14064LFI-Validation2018-07-06T10:10:46Z<p>Azacchei: /* Null tests approach */</p>
<hr />
<div>{{DISPLAYTITLE:Overall internal validation}}<br />
== Overview ==<br />
Data validation is critical at each step of the analysis pipeline. Much of the LFI data validation is based on null tests. Here we present some examples from the current release, with comments on relevant time scales and sensitivity to various systematics.<br />
<br />
== Null tests approach ==<br />
Null tests at map level are performed routinely, whenever changes are made to the mapmaking pipeline. These include differences at survey, year, 2-year, half- mission and half-ring levels, for single detectors, horns, horn pairs and full frequency complements. Where possible, map differences are generated in <i>I</i>, <i>Q</i> and <i>U</i>. <br />
For this release, we use the Full Focal Plane 10 (FFP10) simulations for comparison. We can use FFP10 noise simulations, identical to the data in terms of sky sampling and with matching time domain noise characteristics, to make statistical arguments about the likelihood of the noise observed in the actual data nulls.<br />
In general null tests are performed to highlight possible issues in the data related to instrumental systematic effecst not properly accounted for within the processing pipeline, or related to known changes in the operational conditions (e.g., switch-over of the sorption coolers), or related to intrinsic instrument properties coupled with the sky signal, such as stray light contamination.<br />
Such null-tests can be performed by using data on different time scales ranging from 1 minute to 1 year of observations, at different unit levels (radiometer, horn, horn-pair), within frequency and cross-frequency, both in total intensity, and, when applicable, in polarization.<br />
<br />
=== Sample Null Maps ===<br />
<br />
<gallery mode="nolines"><br />
File:PlanckFig_map_Diff030full_ringhalf_1-full_ringhalf_2sm3I_Stokes_88mm.png<br />
File:PlanckFig_map_Diff030full_ringhalf_1-full_ringhalf_2sm3Q_Stokes_88mm.png<br />
File:PlanckFig_map_Diff030yr1+yr3-yr2+yr4sm3Q_Stokes_88mm.png<br />
File:PlanckFig_map_Diff030yr1+yr3-yr2+yr4sm3I_Stokes_88mm.png<br />
</gallery><br />
<gallery mode="nolines"><br />
File:PlanckFig_map_Diff044full_ringhalf_1-full_ringhalf_2sm3I_Stokes_88mm.png<br />
File:PlanckFig_map_Diff044full_ringhalf_1-full_ringhalf_2sm3Q_Stokes_88mm.png<br />
File:PlanckFig_map_Diff044yr1+yr3-yr2+yr4sm3Q_Stokes_88mm.png<br />
File:PlanckFig_map_Diff044yr1+yr3-yr2+yr4sm3I_Stokes_88mm.png<br />
</gallery><br />
<gallery mode="nolines"><br />
File:PlanckFig_map_Diff070full_ringhalf_1-full_ringhalf_2sm3I_Stokes_88mm.png<br />
File:PlanckFig_map_Diff070full_ringhalf_1-full_ringhalf_2sm3Q_Stokes_88mm.png<br />
File:PlanckFig_map_Diff070yr1+yr3-yr2+yr4sm3Q_Stokes_88mm.png<br />
File:PlanckFig_map_Diff070yr1+yr3-yr2+yr4sm3I_Stokes_88mm.png<br />
</gallery><br />
'''<small>Figure 1: Null map samples for 30GHz (top), 44GHz (middle), and 70GHz (bottom). From left to right: half-ring differences in <i>I</i> and <i>Q</i>; 2-year combination differences in <i>I</i> and <i>Q</i>. All maps are smoothed to 3&deg;.</small>'''<br />
<br />
<br />
Three things are worth pointing out generally about these maps.<br />
Firstly, there are no obvious "features" standing out at this resolution and noise level. Earlier versions of the data processing, where there were errors in calibration for instance, would show scan-correlated structures at much larger amplitude.<br />
Secondly, the half-ring difference maps and the 2-year combination difference maps give a very similar overall impression. This is a very good sign, as these two types of null map cover very different time scales (1 hour to 2 years).<br />
Thirdly, it is impossible to know how "good" the test is just by looking at the map. There is clearly noise, but determining if it is consistent with the noise model of the instrument, and further, if it will bias the scientific results, requires more analysis.<br />
<br />
===Statistical Analyses===<br />
The next level of data compression is to use the angular power spectra of the null tests, and to compare to simulations in a statistically robust way. We use two different approaches. <br />
In the first we compare pseudo-spectra of the null maps to the half-ring spectra, which are the most "free" of anticipated systmatics. <br />
In the second, we use noise Monte Carlos from the FFP8 simulations, where we run the mapmaking identically to the real data, over data sets with identical sampling to the real data but consisting of noise only generated to match the per-detector LFI noise model. <br />
<br />
Here we show examples comparing the pseudo-spectra of a set of 100 Monte Carlos to the real data. We mask both data and simlations to concentrate on residuals impacting CMB analyses away from the Galactic plane.<br />
<br />
[[File:null_cl_ffp8_070yr1+yr3-yr2+yr4_TT_lin_88mm.png|thumb|center|400px]]<br />
[[File:null_cl_ffp8_070yr1+yr3-yr2+yr4_TT_log88mm.png|thumb|center|400px|'''Figure 2: Pseudo-spectrum comparison (70GHz <i>TT</i>) of 2-year data difference (Year(1+3)-Year(2+4) in green) to the FFP8 simulation distribution (blue error bars).''']]<br />
<br />
[[File:null_cl_ffp8_070yr1+yr3-yr2+yr4_EE_lin_88mm.png|thumb|center|400px]]<br />
[[File:null_cl_ffp8_070yr1+yr3-yr2+yr4_EE_log88mm.png|thumb|center|400px|'''Figure 3: Pseudo-spectrum comparison (70GHz <i>EE</i>) of 2-year data difference (Year(1+3)-Year(2+4) in green) to the FFP8 simulation distribution (blue error bars).''']]<br />
<br />
[[File:null_cl_ffp8_070yr1+yr3-yr2+yr4_BB_lin_88mm.png|thumb|center|400px]]<br />
[[File:null_cl_ffp8_070yr1+yr3-yr2+yr4_BB_log88mm.png|thumb|center|400px|'''Figure 4: Pseudo-spectrum comparison(70GHz <i>BB</i>) of 2-year data difference (Year(1+3)-Year(2+4) in green) to the FFP8 simulation distribution (blue error bars).''']]<br />
<br />
Finally, we can look at the distribution of noise power from the Monte Carlos "&#8467; by &#8467;" and check where the real data fall in that distribution, to see if it is consistent with noise alone.<br />
<br />
[[File:ffp8_dist_070full-survey_1survey_3_TT88mm_nt.png|350px|]]<br />
[[File:ffp8_dist_070full-survey_1survey_3_EE88mm_nt.png|350px|]]<br />
[[File:ffp8_dist_070full-survey_1survey_3_BB88mm_nt.png|350px|]]<br />
<br />
'''<small>Figure 5: Sample 70GHz null test in comparison with FFP8 null distribution for multipoles from 2 to 4. From left to right we show <i>TT</i>, <i>EE</i>, <i>BB</i>. In this case, the null test is the full mission map - (Survey 1+Survey 3). We report the probability to exceed (PTE) values for the data relative to the FFP8 noise-only distributions. All values for this example are very reasonable, suggesting that our noise model captures the important features of the data even at low multipoles.</small>'''<br />
<br />
==Consistency checks ==<br />
<br />
All the details of consistency tests performed can be found in {{PlanckPapers|planck2013-p02}} and {{PlanckPapers|planck2014-a03||Planck-2015-A03}}. <br />
<br />
===Intra-frequency consistency check===<br />
We have tested the consistency between 30, 44, and 70GHz maps by comparing the power spectra in the multipole range around the first acoustic peak. In order to do so, we have removed the estimated contribution from unresolved point source from the spectra. We have then built scatter plots for the three frequency pairs, i.e., 70GHz versus 30 GHz, 70GHz versus 44GHz, and 44GHz versus 30GHz, and performed a linear fit, accounting for errors on both axes.<br />
The results reported in Fig. 6 show that the three power spectra are consistent within the errors. Moreover, note that the current error budget does not account for foreground removal, calibration, and window function uncertainties. Hence, the observed agreement between spectra at different frequencies can be considered to be even more satisfactory.<br />
<br />
[[File:LFI_70vs44_DX11D_maskTCS070vs060_a.jpg|thumb|center|400px|]][[File:LFI_70vs30_DX11D_maskTCS070vs040_a.jpg|thumb|center|400px|]][[File:LFI_44vs30_DX11D_maskTCS060vs040_a.jpg|thumb|center|400px|'''Figure 6: Consistency between spectral estimates at different frequencies. From top to bottom: 70GHz versus 44 GHz; 70GHz versus 30 GHz; and 44GHz versus 30 GHz. Solid red lines are the best fit of the linear regressions, whose angular coefficients &alpha; are consistent with unity within the errors.''']]<br />
<br />
===70 GHz internal consistency check===<br />
We use the Hausman test {{BibCite|polenta_CrossSpectra}} to assess the consistency of auto- and cross-spectral estimates at 70 GHz. We specifically define the statistic:<br />
<br />
:<math><br />
H_{\ell}=\left(\hat{C_{\ell}}-\tilde{C_{\ell}}\right)/\sqrt{{\rm Var}\left\{ \hat{C_{\ell}}-\tilde{C_{\ell}}\right\} },<br />
</math><br />
<br />
where <math>\hat{C_{\ell}}</math> and <math>\tilde{C_{\ell}}</math> represent auto- and<br />
cross-spectra, respectively. In order to combine information from different multipoles into a single quantity, we define<br />
<br />
:<math><br />
B_{L}(r)=\frac{1}{\sqrt{L}}\sum_{\ell=2}^{[Lr]}H_{\ell},r\in\left[0,1\right],<br />
</math><br />
<br />
where square brackets denote the integer part. The distribution of <i>B<sub>L</sub></i>(<i>r</i>)<br />
converges (in a functional sense) to a Brownian motion process, which can be studied through the statistics<br />
<i>s</i><sub>1</sub>=sup<sub><i>r</i></sub><i>B<sub>L</sub></i>(<i>r</i>),<br />
<i>s</i><sub>2</sub>=sup<sub><i>r</i></sub>|<i>B<sub>L</sub></i>(<i>r</i>)|, and<br />
<i>s</i><sub>3</sub>=&#8747;<sub>0</sub><sup>1</sup><i>B<sub>L</sub></i><sup>2</sup>(<i>r</i>)dr. Using the "FFP7" simulations,<br />
we derive empirical distributions for all the three test statistics and compare with results obtained from Planck data<br />
(see Fig. 7). We find that the Hausman test shows no statistically significant inconsistencies between the two spectral<br />
estimates.<br />
<br />
[[File:cons2.jpg|thumb|center|800px|'''Figure 7: From left to right, the empirical<br />
distribution (estimated via FFP7) of the <i>s</i><sub>1</sub>, <i>s</i><sub>2</sub>, and <i>s</i><sub>3</sub><br />
statistics (see text). The vertical line represents 70GHz data.''']]<br />
<br />
As a further test, we have estimated the temperature power spectrum for each of three horn-pair maps, and have compared the<br />
results with the spectrum obtained from all 12 radiometers shown above. In Fig. 8 we plot the<br />
difference between the horn-pair and the combined power spectra.<br />
Again, the error bars have been estimated from the FFP7 simulated data set. A &chi;<sup>2</sup> analysis of the residual shows that they are compatible with the null hypothesis, confirming the<br />
strong consistency of the estimates.<br />
<br />
[[File:cons3.jpg|thumb|center|500px|'''Figure 8: Residuals between the auto-power spectra of the horn-pair maps and the power spectrum of the full 70GHz frequency map. Error bars here are derived from FFP7 simulations.''']]<br />
<br />
<!--<br />
== Data Release Results ==<br />
<br />
=== Impact on cosmology ===<br />
--><br />
<br />
== References ==<br />
<br />
<References /><br />
<br />
<br />
[[Category:LFI data processing|006]]</div>Azaccheihttps://wiki.cosmos.esa.int/planck-legacy-archive/index.php?title=LFI_systematic_effect_uncertainties&diff=14061LFI systematic effect uncertainties2018-07-06T09:51:56Z<p>Azacchei: </p>
<hr />
<div>{{DISPLAYTITLE:Systematic effect uncertainties}}<br />
== Overview ==<br />
<br />
Known systematic effects in the Planck-LFI data can be divided into two broad categories: effects independent of the sky signal, which can be considered as additive or multiplicative spurious contributions to the measured timelines, and effects which are dependent on the sky and that cannot be considered independently from the observation strategy.<br />
<br />
Here we report a brief summary of these effects, all the details can be found in {{PlanckPapers|planck2013-p02a}} and {{PlanckPapers|planck2014-a04||Planck-2015-A04}}.<br />
Systematic error budget remains essentially unchanged from the 2015 release see {{PlanckPapers|planck2016-l02}} for futher details.<br />
<br />
==Summary of uncertainties due to systematic effects==<br />
In this section we provide a top-level overview of the uncertainties due to systematic effects in the Planck-LFI CMB temperature maps and power spectra. Table 1 provides a list of these effects with short indications of their cause, strategies for removal and references to sections and/or papers where more information is found.<br />
<br />
{| border="1" cellspacing="0" cellpadding="2" align="center"<br />
|+ <small>'''Table 1. List of known instrumental systematic effects in Planck LFI.'''</small><br />
|-<br />
!scope="col"| Effect <br />
!scope="col"| Source <br />
!scope="col"| Control/Removal<br />
!scope="col"| Reference<br />
|-<br />
!width="280" | Effects independent of sky signal (T and P)<br />
|width="220" |<br />
|width="220" |<br />
|width="140" |<br />
|-<br />
|width="280" | White noise correlation<br />
|width="220" | Phase-switch imbalance<br />
|width="220" | Diode weighting<br />
|width="140" | {{PlanckPapers|planck2013-p02a}} {{PlanckPapers|planck2014-a04||Planck-2015-A04}}<br />
|-<br />
|width="280" | 1/<i>f</i> noise<br />
|width="220" | RF amplifiers<br />
|width="220" | Pseudo-correlation and destriping<br />
|width="140" | {{PlanckPapers|planck2013-p02a}} {{PlanckPapers|planck2014-a04||Planck-2015-A04}}<br />
|- <br />
|width="280" | Bias fluctuations <br />
|width="220" | RF amplifiers, back-end electronics&<br />
|width="220" | Pseudo-correlation and destriping <br />
|width="140" | {{PlanckPapers|planck2014-a03||Planck-2015-A03}}<br />
|- <br />
|width="280" | Thermal fluctuations<br />
|width="220" | 4-K, 20-K and 300-K thermal stages<br />
|width="220" | Calibration, destriping<br />
|width="140" | {{PlanckPapers|planck2014-a03||Planck-2015-A03}}<br />
|- <br />
|width="280" | 1-Hz spikes<br />
|width="220" | Back-end electronics<br />
|width="220" | Template fitting and removal<br />
|width="140" | {{PlanckPapers|planck2014-a03||Planck-2015-A03}}<br />
|-<br />
!width="280" | Effects dependent on sky signal (T and P)<br />
|width="220" |<br />
|width="220" |<br />
|width="140" |<br />
|-<br />
|width="280" | Main beam ellipticity<br />
|width="220" | Main beams<br />
|width="220" | Accounted for in window function<br />
|width="140" | {{PlanckPapers|planck2014-a03||Planck-2015-A03}}<br />
|-<br />
|width="280" | Near sidelobes pickup<br />
|width="220" | Optical response at angles 5&deg; from the main beam<br />
|width="220" | Masking of Galaxy and point sources<br />
|width="140" | {{PlanckPapers|planck2014-a03||Planck-2015-A03}}<br />
|-<br />
|width="280" | Far sidelobes pickup<br />
|width="220" | Main and sub-reflector spillovers<br />
|width="220" | Model sidelobes removed from timelines <br />
|width="140" | {{PlanckPapers|planck2014-a03||Planck-2015-A03}}<br />
|-<br />
|width="280" | Analogue-to-digital converter nonlinearity<br />
|width="220" | Back-end analogue-to-digital converter<br />
|width="220" | Template fitting and removal <br />
|width="140" | {{PlanckPapers|planck2014-a03||Planck-2015-A03}}<br />
|-<br />
|width="280" | Imperfect photometric calibration<br />
|width="220" | Sidelobe pickup, radiometer noise temperature changes and other non-idealities<br />
|width="220" | Calibration using the 4-K reference load voltage output<br />
|width="140" | {{PlanckPapers|planck2014-a03||Planck-2015-A03}}<br />
|-<br />
|width="280" | Pointing <br />
|width="220" | Uncertainties in pointing reconstruction, thermal changes affecting focal plane geometry<br />
|width="220" | Negligible impact anisotropy measurements<br />
|width="140" | {{PlanckPapers|planck2014-a03||Planck-2015-A03}}<br />
|-<br />
!width="280" | Effects specifically impacting polarization<br />
|width="220" |<br />
|width="220" |<br />
|width="140" |<br />
|-<br />
|width="280" | Bandpass asymmetries<br />
|width="220" | Differential orthomode transducer and receiver bandpass response<br />
|width="220" | Spurious polarization removal<br />
|width="140" | {{PlanckPapers|planck2014-a03||Planck-2015-A03}}<br />
|-<br />
|width="280" | Polarization angle uncertainty<br />
|width="220" | Uncertainty in the polarization angle in-flight measurement<br />
|width="220" | Negligible impact<br />
|width="140" | {{PlanckPapers|planck2014-a03||Planck-2015-A03}}<br />
|-<br />
|width="280" | Orthomode transducer cross-polarization<br />
|width="220" | Imperfect polarization separation <br />
|width="220" | Negligible impact <br />
|width="140" | {{PlanckPapers|planck2014-a03||Planck-2015-A03}}<br />
|-<br />
|}<br />
<br />
The impact of 1/<i>f</i> noise has been assessed using half-ring noise maps normalized to the white noise estimate at each pixel (obtained from the white noise covariance matrix), so that a perfectly white noise map would be Gaussian and isotropic with unit variance. Deviations from unity trace the contribution of residual 1/<i>f</i> noise in the final maps, which ranges from 0.06% at 70 GHz to 2% at 30 GHz.<br />
Pixel uncertainties due to other systematic effects have been calculated on simulated maps degraded to <i>N</i><sub>side</sub> = 128 at 30 and 44 GHz and <i>N</i><sub>side</sub> = 256 at 70 GHz, in order to approximate the optical beam size. This downgrading has been applied in all cases that a systematic effect has been evaluated at map level.<br />
<br />
In Table 2 we list the rms and the difference between the 99% and the 1% quantities in the pixel value distributions. For simplicity we refer to this difference as the "peak-to-peak" (p-p) difference, although it neglects outliers but effectively approximates the peak-to-peak variation of the effect on the map.<br />
<br />
<center><br />
<small>'''Table 2. Summary of systematic effects uncertainties on maps in μK<sub>CMB</sub> units.'''</small><br />
</center><br />
<br />
{| border="0" cellspacing="0" cellpadding="2" align="center"<br />
|width="450"| <center>'''30 GHz'''</center> <br />
|-<br />
|width="450"| [[File:Selection_263.png|450px]]<br />
|-<br />
|width="450"| <center>'''44 GHz'''</center> <br />
|-<br />
|width="450"| [[File:Selection_261.png|450px]]<br />
|-<br />
|width="450"| <center>'''70 GHz'''</center> <br />
|-<br />
|width="450"| [[File:Selection_262.png|450px]]<br />
|}<br />
<br />
Angular power spectra have been obtained from full resolution (<i>N</i><sub>side</sub> = 1024) systematic effect maps at each frequency using the HEALPix Anafast routine {{BibCite|gorski2005}}. In Fig. 1 we show the power spectrum of the various effects compared with the Planck best-fit spectra and with the noise level coming from the half-ring difference maps. <br />
<br />
Our assessment shows that the global impact of systematic effect uncertainties in the LFI do not limit either temperature or <i>E</i>-mode spectrum measurements.<br />
<center><br />
[[File:Selection_264.png|900px]]<br />
<br />
[[File:Selection_265.png|900px]]<br />
<br />
[[File:Selection_266.png|900px]]<br />
<br />
<small>'''Figure 1. Angular power spectra of the various systematic effects compared to the Planck beam-filtered temperature and polarization spectra. The thick dark-grey curve represents the total contribution. The dark-green dotted curve represent the contribution from far sidelobes that has been removed from the data and, therefore not considered in the total. The CMB <i>TT</i> and <i>EE</i> curves correspond to the Planck best-fit power spectra. The theoretical <i>B</i>-mode CMB spectrum assumes a tensor-to-scalar ratio <i>r</i> = 0.1, a tensor spectral index <i>n</i><sub>T</sub>=0 and has not been beam-filtered. ''Rows'': 30, 44 and 70 GHz spectra. ''Columns'': temperature, <i>E</i>-mode and <i>B</i>-mode spectra. .'''</small><br />
</center><br />
<br />
==Effect of main systematic at power spectra level==<br />
Systematic error budget remains essentially unchanged from the 2015 release, for the present release we concentrte on developing a detailed simulation programme to model all known instrumental and astrophysical effects that produce ubncertainity in the gain for polarization data. The table below reported ummarizes systematic effects at the power spectrum level for three multipole ranges, see {{PlanckPapers|planck2016-l02}} for futher details.<br />
<br />
[[File:Table_9.png|900px]]<br />
<br />
<br />
==Detailed description of the various effects==<br />
<br />
A detailed description of the impact of the various effects is contained in the paper {{PlanckPapers|planck2014-a04||Planck-2015-A04}}.<br />
<br />
<br />
<!--<br />
<br />
A detailed description of the impact of the various effects is contained in the paper being prepared for the submission of a dedicated paper to A&A and will also appear in this supplement. We expect it to be available by the end of February.<br />
<br />
<br />
==Effects independent of sky signal==<br />
===Noise correlations and 1/<i>f</i> noise===<br />
TBW<br />
<br />
<br />
As described in Ref. {{BibCite|seiffert2002}} and {{PlanckPapers|planck2011-1-4}}, imperfect matching of components generates isolation between the complementary diodes of a receiver between −10 and −15 dB. This imperfect isolation leads to a small anti-correlated component in the white noise that is cancelled by a weighted average of the time-ordered data from the two diodes of each receiver as the first step of athe processing. This avoids the complication of tracking the anti-correlated white noise throughout the analysis.<br />
We treat the combined diode data as the raw data, and calibration, noise estimation, mapmaking etc. are performed on these combined data. The weights are determined from some initial estimates of the calibrated noise for each detector, and are kept fixed for the entire mission.<br />
<br />
We estimate the signal-subtracted noise power spectrum of each receiver on 5-day time periods. Except for specific, mostly well understood events, shorter<br />
timescale noise estimation does not produce any evident trends. For nearly all the radiometers our noise model is a very good approximation of the power spectrum. <br />
<br />
Over the course of the nominal mission, the noise is well fit by the model, with the exception of the early parts of Survey 3. During this time, thermal instabilities brought on by the switchover from the nominal to the redundant sorption cooler cause poor fits and some changes in the parameters.<br />
<br />
===Thermal effects===<br />
<br />
TBW<br />
<br />
The LFI is susceptible to temperature fluctuations in the 300-K back-end modules, in the 4-K reference loads and in the 20-K focal plane. <br />
<br />
The temperature of 70-GHz reference loads was actively controlled by a proportional-integral-derivative (PID) system and is very stable (δ<i>T</i><sub>rms</sub> ∼ 0.13 mK). Reference loads of 30 and 44 GHz channels, instead, do not benefit from active thermal control. Their temperature is consequently more unstable and susceptible to major system-level events such as, for example, the switchover to the redundant sorption cooler.<br />
<br />
The 20-K LFI focal plane temperature was measured by a sensor placed on the feedhorn flange of the LFI-28 receiver. The temperature during the first sky survey was very stable. Towards the end of the first year of operations the sorption cooler performance started to degrade and its stability was maintained with a series of controlled temperature changes. The switchover to the redundant cooler left a clear signature on all the main LFI temperatures. After this operation the level of temperature fluctuations on the focal plane increased unexpectedly, and this was later understood to be the effect of liquid hydrogen that was still present in the cold-end of the nominal cooler, because of the degraded compressor system not being able to absorb all the hydrogen that was present in the cooler line. Although this effect was later mitigated by a series of dedicated operations, most of the third sky survey suffered from a higher-than-nominal level of temperature variations.<br />
<br />
The temperature of the 300-K electronics box was measured by one of its temperature sensors. During the first sky survey the back-end temperature suffered from a 24-hour fluctuation caused by the satellite transponder that was switched on daily during contact with the ground station. After day 258 the system was left continuously on and the 24-hour modulation disappeared. This operation caused an increase of the absolute temperature level. The second temperature change that occurred corresponded to the sorption cooler switch-over operation. A yearly temperature modulation due to the satellite rotation around the Sun and a specific temperature spike need also to be considered. This was caused by an operational anomaly that caused the satellite to fail to repoint for an entire day, with a corresponding temperature increase of the warm units.<br />
<br />
Details regarding the thermal stability performance of Planck can be found in {{PlanckPapers|planck2011-1-3}}, while the susceptibility of the LFI to temperature variations is discussed in Ref. {{BibCite|terenzi2009b}}.<br />
<br />
<br />
<br />
===Bias fluctuations===<br />
<br />
TBW<br />
<br />
<br />
The signal detected by the radiometers can vary because of fluctuations in the front-end and back-end amplifier bias voltages. In the LFI these fluctuations occurred on two timescales:<br />
* slow electric drifts, due to thermal changes in the power supply, in the RF amplifiers, and in the detector diodes;<br />
* fast and sudden electric instabilities, arising in the warm electronics or from electromagnetic interference effects, and affecting both the cold amplifiers and the warm detector diodes.<br />
<br />
The effect of slow drifts is suppressed by the pseudo-correlation architecture of the differential radiometers. Fast electric changes produce quasi-random fluctuations and abrupt steep drops or jumps in the signal. If jumps are caused by instabilities in the front-end bias voltage then the effect involves the output voltage of both diodes in the radiometer. When the jumps occur in the back-end detector diodes (so-called “pop-corn noise”) they impact only the output voltage of the corresponding diode, affecting sky and reference load samples. In both cases the differenced signal is largely immune from these effects.<br />
<br />
<br />
===1-Hz spikes===<br />
<br />
TBW<br />
<br />
An effect at 1 Hz is caused by pickup from the housekeeping electronics clock that occurs in the chain after the detector diodes and before the ADC converters {{PlanckPapers|planck2011-1-4}}{{BibCite|meinhold2009}}{{PlanckPapers|mennella2010}}. This spurious signal is detected in the radiometer time-domain outputs as a 1-s square wave with a rising edge near 0.5 s and a falling edge near 0.75 s in on-board time. In the frequency domain it appears at multiples of 1 Hz.<br />
Frequency spikes are present at some level in the output from all detectors, but affect the 44 GHz data most strongly because of the low voltage output and high post-detection gain values in that channel. For this reason spikes are removed from the 44 GHz time-ordered data via template fitting, as described in {{PlanckPapers|planck2013-p02}}.<br />
<br />
<br />
===Main beam ellipticity===<br />
TBW<br />
<br />
===Near sidelobe pickup===<br />
TBW<br />
<br />
==Effects dependent on sky signal==<br />
===Sidelobe pick-up===<br />
<br />
TBW<br />
<br />
<br />
Straylight contamination arises from the spurious signal pickup from the telescope far sidelobes. The main sources of straylight contamination are the Galaxy, especially at 30 GHz, and the cosmological dipole, mainly detected in the directions of the main reflector and sub-reflector spillover. In principle we should also include the straylight contribution from the orbital dipole, but its effect is about a factor ten lower than the cosmic dipole so that it can safely be neglected in this framework (although it has been considered in the calibration pipeline). Further details about the Planck optical system are reported in {{PlanckPapers|tauber2010b}} and the LFI beam properties are provided in {{PlanckPapers|sandri2010}}.<br />
<br />
Straylight impacts the measured signal essentially in two ways: (i) through direct contamination and coupling with the main beam sky signal; and (ii) in the photometric calibration of the radiometer detected signal. The impact on calibration and the adopted mitigation strategies are described in {{PlanckPapers|planck2013-p02b}}.<br />
Because of the beam orientation, the straylight fingerprint is different in odd surveys compared to even surveys. The Galaxy, for example, is detected by the sub-reflector spillover in the odd surveys and by the main reflector spillover in the even surveys. Because the sub-reflector spillover points approximately in the main beam direction, the Galaxy straylight pattern is close to the Galactic plane. The main spillover, instead, points at about 85&deg; from the main beam so that the Galaxy is re-imaged onto a ring.<br />
<br />
<br />
===ADC nonlinearity===<br />
<br />
TBW<br />
<br />
The linearity of analogue-to-digital converters (ADC) requires that the voltage step sizes between successive binary outputs are<br />
constant over the entire input dynamic range. If these steps are not constant we have a nonlinearity in the ADC response that leads to calibration errors.<br />
<br />
The typical fingerprint of ADC non linearity is a variation of the detector voltage output white noise that is not matched by a detectable variation in the voltage level. This effect was observed in the LFI radiometer data for the first time in flight, where drops of a few percent were observed in the voltage white noise, but not in the output level over, periods of few weeks. <br />
The typical amplitude of the region where the nonlinearity occurs is of the order of 1 mV, corresponding to about three bits in the ADC. The ADC effect is strongest (3% to 6%) in the 44 GHz channels, because of their lower detector voltages. The ADC nonlinearity effect has been characterized from flight data and removed from the TOIs according to the procedure described in the main LFI data processing paper {{PlanckPapers|planck2013-p02}}.<br />
<br />
<br />
<br />
===Imperfect photometric calibration===<br />
<br />
<br />
An important set of systematic effects are those related to the photometric calibration of the radiometers. Such effects are discussed at length in {{PlanckPapers|planck2013-p05}}. There are three different kinds of systematic effects that can affect the calibration.<br />
<br />
* Incorrect assumptions regarding the calibration signal. In the case of LFI, the signal used for the calibration is the dipolar field caused by the motion of the Solar System with respect to the CMB rest frame and by the motion of the spacecraft around the Sun. We model the former using the values quoted by Ref. {{BibCite}} and the latter using the spacecraft’s attitude information. Any error in the numbers would directly lead to an error in the calibration of Planck-LFI data.<br />
* Incorrect treatment of the calibration signal. To actually use any previous knowledge of the CMB dipole, we need to convolve the signal with the beam response of each LFI radiometer. Any error in this step would produce a systematic effect in the map, not only because of the incorrect shape expected for the calibration signal, but also because of the removal of the (wrong) dipole from the calibrated maps performed by the Planck-LFI pipeline {{PlanckPapers|planck2013-p02}}. Possible types of errors include: systematic errors in Planck’s dipole estimate; wrong convolution of the expected dipole with the radiometer beams; and incorrect masking of the Galaxy when fitting the observed signal with the dipole.<br />
* Incorrect reconstruction of gain fluctuations. Some of the algorithms adopted in calibrating LFI data for this release use the radiometer equation and the recorded variations of the radiometer total-power output to track gain changes. In principle, any deviation in the behaviour of the radiometer from the ideal case (e.g., ADC nonlinearities) can therefore induce systematic effects in the gain curves.<br />
<br />
<br />
<br />
===Pointing effects===<br />
<br />
TBW<br />
<br />
<br />
Pointing uncertainties are translated into uncertainties in pixel temperature measurements. If pointing uncertainties are not constant in time then the statistics of the sky anisotropy measurements are not preserved, with a consequent impact on the power spectrum and cosmological parameters. In Planck-LFI pointing uncertainties arise from two distinct sources.<br />
* Satellite pointing determination. The Planck Attitude Control Movement System guarantees a pointing accuracy of approximately 2′′ {{PlanckPapers|planck2013-p01}}, which is well within scientific requirements. However, small non-idealities in the system and errors in the attitude reconstruction caused, for example, by thermoelastic effects, can still affect the data.<br />
* Uncertainties in the focal plane geometry reconstruction. The measurement of the LFI focal plane geometry is based on the determination of the beam pointing with respect to the nominal line of sight, exploiting observations of Jupiter. The peak of each beam was determined by fitting data with a bivariate Gaussian function, which may be not be precisely equivalent to the real beam centre.<br />
<br />
<br />
<br />
===Polarization angle uncertainty===<br />
TBW<br />
<br />
===Ortho-mode transducer cross-polarization===<br />
TBW<br />
<br />
--><br />
<br />
== References ==<br />
<br />
<References /><br />
<br />
<br />
<br />
[[Category:LFI data processing|005]]</div>Azaccheihttps://wiki.cosmos.esa.int/planck-legacy-archive/index.php?title=File:Table_9.png&diff=14060File:Table 9.png2018-07-06T09:50:01Z<p>Azacchei: </p>
<hr />
<div></div>Azaccheihttps://wiki.cosmos.esa.int/planck-legacy-archive/index.php?title=LFI_systematic_effect_uncertainties&diff=14059LFI systematic effect uncertainties2018-07-06T09:49:35Z<p>Azacchei: </p>
<hr />
<div>{{DISPLAYTITLE:Systematic effect uncertainties}}<br />
== Overview ==<br />
<br />
Known systematic effects in the Planck-LFI data can be divided into two broad categories: effects independent of the sky signal, which can be considered as additive or multiplicative spurious contributions to the measured timelines, and effects which are dependent on the sky and that cannot be considered independently from the observation strategy.<br />
<br />
Here we report a brief summary of these effects, all the details can be found in {{PlanckPapers|planck2013-p02a}} and {{PlanckPapers|planck2014-a04||Planck-2015-A04}}.<br />
Systematic error budget remains essentially unchanged from the 2015 release see {{PlanckPapers|planck2016-l02}} for futher details.<br />
<br />
==Summary of uncertainties due to systematic effects==<br />
In this section we provide a top-level overview of the uncertainties due to systematic effects in the Planck-LFI CMB temperature maps and power spectra. Table 1 provides a list of these effects with short indications of their cause, strategies for removal and references to sections and/or papers where more information is found.<br />
<br />
{| border="1" cellspacing="0" cellpadding="2" align="center"<br />
|+ <small>'''Table 1. List of known instrumental systematic effects in Planck LFI.'''</small><br />
|-<br />
!scope="col"| Effect <br />
!scope="col"| Source <br />
!scope="col"| Control/Removal<br />
!scope="col"| Reference<br />
|-<br />
!width="280" | Effects independent of sky signal (T and P)<br />
|width="220" |<br />
|width="220" |<br />
|width="140" |<br />
|-<br />
|width="280" | White noise correlation<br />
|width="220" | Phase-switch imbalance<br />
|width="220" | Diode weighting<br />
|width="140" | {{PlanckPapers|planck2013-p02a}} {{PlanckPapers|planck2014-a04||Planck-2015-A04}}<br />
|-<br />
|width="280" | 1/<i>f</i> noise<br />
|width="220" | RF amplifiers<br />
|width="220" | Pseudo-correlation and destriping<br />
|width="140" | {{PlanckPapers|planck2013-p02a}} {{PlanckPapers|planck2014-a04||Planck-2015-A04}}<br />
|- <br />
|width="280" | Bias fluctuations <br />
|width="220" | RF amplifiers, back-end electronics&<br />
|width="220" | Pseudo-correlation and destriping <br />
|width="140" | {{PlanckPapers|planck2014-a03||Planck-2015-A03}}<br />
|- <br />
|width="280" | Thermal fluctuations<br />
|width="220" | 4-K, 20-K and 300-K thermal stages<br />
|width="220" | Calibration, destriping<br />
|width="140" | {{PlanckPapers|planck2014-a03||Planck-2015-A03}}<br />
|- <br />
|width="280" | 1-Hz spikes<br />
|width="220" | Back-end electronics<br />
|width="220" | Template fitting and removal<br />
|width="140" | {{PlanckPapers|planck2014-a03||Planck-2015-A03}}<br />
|-<br />
!width="280" | Effects dependent on sky signal (T and P)<br />
|width="220" |<br />
|width="220" |<br />
|width="140" |<br />
|-<br />
|width="280" | Main beam ellipticity<br />
|width="220" | Main beams<br />
|width="220" | Accounted for in window function<br />
|width="140" | {{PlanckPapers|planck2014-a03||Planck-2015-A03}}<br />
|-<br />
|width="280" | Near sidelobes pickup<br />
|width="220" | Optical response at angles 5&deg; from the main beam<br />
|width="220" | Masking of Galaxy and point sources<br />
|width="140" | {{PlanckPapers|planck2014-a03||Planck-2015-A03}}<br />
|-<br />
|width="280" | Far sidelobes pickup<br />
|width="220" | Main and sub-reflector spillovers<br />
|width="220" | Model sidelobes removed from timelines <br />
|width="140" | {{PlanckPapers|planck2014-a03||Planck-2015-A03}}<br />
|-<br />
|width="280" | Analogue-to-digital converter nonlinearity<br />
|width="220" | Back-end analogue-to-digital converter<br />
|width="220" | Template fitting and removal <br />
|width="140" | {{PlanckPapers|planck2014-a03||Planck-2015-A03}}<br />
|-<br />
|width="280" | Imperfect photometric calibration<br />
|width="220" | Sidelobe pickup, radiometer noise temperature changes and other non-idealities<br />
|width="220" | Calibration using the 4-K reference load voltage output<br />
|width="140" | {{PlanckPapers|planck2014-a03||Planck-2015-A03}}<br />
|-<br />
|width="280" | Pointing <br />
|width="220" | Uncertainties in pointing reconstruction, thermal changes affecting focal plane geometry<br />
|width="220" | Negligible impact anisotropy measurements<br />
|width="140" | {{PlanckPapers|planck2014-a03||Planck-2015-A03}}<br />
|-<br />
!width="280" | Effects specifically impacting polarization<br />
|width="220" |<br />
|width="220" |<br />
|width="140" |<br />
|-<br />
|width="280" | Bandpass asymmetries<br />
|width="220" | Differential orthomode transducer and receiver bandpass response<br />
|width="220" | Spurious polarization removal<br />
|width="140" | {{PlanckPapers|planck2014-a03||Planck-2015-A03}}<br />
|-<br />
|width="280" | Polarization angle uncertainty<br />
|width="220" | Uncertainty in the polarization angle in-flight measurement<br />
|width="220" | Negligible impact<br />
|width="140" | {{PlanckPapers|planck2014-a03||Planck-2015-A03}}<br />
|-<br />
|width="280" | Orthomode transducer cross-polarization<br />
|width="220" | Imperfect polarization separation <br />
|width="220" | Negligible impact <br />
|width="140" | {{PlanckPapers|planck2014-a03||Planck-2015-A03}}<br />
|-<br />
|}<br />
<br />
The impact of 1/<i>f</i> noise has been assessed using half-ring noise maps normalized to the white noise estimate at each pixel (obtained from the white noise covariance matrix), so that a perfectly white noise map would be Gaussian and isotropic with unit variance. Deviations from unity trace the contribution of residual 1/<i>f</i> noise in the final maps, which ranges from 0.06% at 70 GHz to 2% at 30 GHz.<br />
Pixel uncertainties due to other systematic effects have been calculated on simulated maps degraded to <i>N</i><sub>side</sub> = 128 at 30 and 44 GHz and <i>N</i><sub>side</sub> = 256 at 70 GHz, in order to approximate the optical beam size. This downgrading has been applied in all cases that a systematic effect has been evaluated at map level.<br />
<br />
In Table 2 we list the rms and the difference between the 99% and the 1% quantities in the pixel value distributions. For simplicity we refer to this difference as the "peak-to-peak" (p-p) difference, although it neglects outliers but effectively approximates the peak-to-peak variation of the effect on the map.<br />
<br />
<center><br />
<small>'''Table 2. Summary of systematic effects uncertainties on maps in μK<sub>CMB</sub> units.'''</small><br />
</center><br />
<br />
{| border="0" cellspacing="0" cellpadding="2" align="center"<br />
|width="450"| <center>'''30 GHz'''</center> <br />
|-<br />
|width="450"| [[File:Selection_263.png|450px]]<br />
|-<br />
|width="450"| <center>'''44 GHz'''</center> <br />
|-<br />
|width="450"| [[File:Selection_261.png|450px]]<br />
|-<br />
|width="450"| <center>'''70 GHz'''</center> <br />
|-<br />
|width="450"| [[File:Selection_262.png|450px]]<br />
|}<br />
<br />
Angular power spectra have been obtained from full resolution (<i>N</i><sub>side</sub> = 1024) systematic effect maps at each frequency using the HEALPix Anafast routine {{BibCite|gorski2005}}. In Fig. 1 we show the power spectrum of the various effects compared with the Planck best-fit spectra and with the noise level coming from the half-ring difference maps. <br />
<br />
Our assessment shows that the global impact of systematic effect uncertainties in the LFI do not limit either temperature or <i>E</i>-mode spectrum measurements.<br />
<center><br />
[[File:Selection_264.png|900px]]<br />
<br />
[[File:Selection_265.png|900px]]<br />
<br />
[[File:Selection_266.png|900px]]<br />
<br />
<small>'''Figure 1. Angular power spectra of the various systematic effects compared to the Planck beam-filtered temperature and polarization spectra. The thick dark-grey curve represents the total contribution. The dark-green dotted curve represent the contribution from far sidelobes that has been removed from the data and, therefore not considered in the total. The CMB <i>TT</i> and <i>EE</i> curves correspond to the Planck best-fit power spectra. The theoretical <i>B</i>-mode CMB spectrum assumes a tensor-to-scalar ratio <i>r</i> = 0.1, a tensor spectral index <i>n</i><sub>T</sub>=0 and has not been beam-filtered. ''Rows'': 30, 44 and 70 GHz spectra. ''Columns'': temperature, <i>E</i>-mode and <i>B</i>-mode spectra. .'''</small><br />
</center><br />
<br />
===Effect of main systematic at power spectra level===<br />
Systematic error budget remains essentially unchanged from the 2015 release, for the present release we concentrte on developing a detailed simulation programme to model all known instrumental and astrophysical effects that produce ubncertainity in the gain for polarization data. The table below reported ummarizes systematic effects at the power spectrum level for three multipole ranges, see {{PlanckPapers|planck2016-l02}} for futher details.<br />
<br />
<br />
<br />
<br />
==Detailed description of the various effects==<br />
<br />
A detailed description of the impact of the various effects is contained in the paper {{PlanckPapers|planck2014-a04||Planck-2015-A04}}.<br />
<br />
<br />
<!--<br />
<br />
A detailed description of the impact of the various effects is contained in the paper being prepared for the submission of a dedicated paper to A&A and will also appear in this supplement. We expect it to be available by the end of February.<br />
<br />
<br />
==Effects independent of sky signal==<br />
===Noise correlations and 1/<i>f</i> noise===<br />
TBW<br />
<br />
<br />
As described in Ref. {{BibCite|seiffert2002}} and {{PlanckPapers|planck2011-1-4}}, imperfect matching of components generates isolation between the complementary diodes of a receiver between −10 and −15 dB. This imperfect isolation leads to a small anti-correlated component in the white noise that is cancelled by a weighted average of the time-ordered data from the two diodes of each receiver as the first step of athe processing. This avoids the complication of tracking the anti-correlated white noise throughout the analysis.<br />
We treat the combined diode data as the raw data, and calibration, noise estimation, mapmaking etc. are performed on these combined data. The weights are determined from some initial estimates of the calibrated noise for each detector, and are kept fixed for the entire mission.<br />
<br />
We estimate the signal-subtracted noise power spectrum of each receiver on 5-day time periods. Except for specific, mostly well understood events, shorter<br />
timescale noise estimation does not produce any evident trends. For nearly all the radiometers our noise model is a very good approximation of the power spectrum. <br />
<br />
Over the course of the nominal mission, the noise is well fit by the model, with the exception of the early parts of Survey 3. During this time, thermal instabilities brought on by the switchover from the nominal to the redundant sorption cooler cause poor fits and some changes in the parameters.<br />
<br />
===Thermal effects===<br />
<br />
TBW<br />
<br />
The LFI is susceptible to temperature fluctuations in the 300-K back-end modules, in the 4-K reference loads and in the 20-K focal plane. <br />
<br />
The temperature of 70-GHz reference loads was actively controlled by a proportional-integral-derivative (PID) system and is very stable (δ<i>T</i><sub>rms</sub> ∼ 0.13 mK). Reference loads of 30 and 44 GHz channels, instead, do not benefit from active thermal control. Their temperature is consequently more unstable and susceptible to major system-level events such as, for example, the switchover to the redundant sorption cooler.<br />
<br />
The 20-K LFI focal plane temperature was measured by a sensor placed on the feedhorn flange of the LFI-28 receiver. The temperature during the first sky survey was very stable. Towards the end of the first year of operations the sorption cooler performance started to degrade and its stability was maintained with a series of controlled temperature changes. The switchover to the redundant cooler left a clear signature on all the main LFI temperatures. After this operation the level of temperature fluctuations on the focal plane increased unexpectedly, and this was later understood to be the effect of liquid hydrogen that was still present in the cold-end of the nominal cooler, because of the degraded compressor system not being able to absorb all the hydrogen that was present in the cooler line. Although this effect was later mitigated by a series of dedicated operations, most of the third sky survey suffered from a higher-than-nominal level of temperature variations.<br />
<br />
The temperature of the 300-K electronics box was measured by one of its temperature sensors. During the first sky survey the back-end temperature suffered from a 24-hour fluctuation caused by the satellite transponder that was switched on daily during contact with the ground station. After day 258 the system was left continuously on and the 24-hour modulation disappeared. This operation caused an increase of the absolute temperature level. The second temperature change that occurred corresponded to the sorption cooler switch-over operation. A yearly temperature modulation due to the satellite rotation around the Sun and a specific temperature spike need also to be considered. This was caused by an operational anomaly that caused the satellite to fail to repoint for an entire day, with a corresponding temperature increase of the warm units.<br />
<br />
Details regarding the thermal stability performance of Planck can be found in {{PlanckPapers|planck2011-1-3}}, while the susceptibility of the LFI to temperature variations is discussed in Ref. {{BibCite|terenzi2009b}}.<br />
<br />
<br />
<br />
===Bias fluctuations===<br />
<br />
TBW<br />
<br />
<br />
The signal detected by the radiometers can vary because of fluctuations in the front-end and back-end amplifier bias voltages. In the LFI these fluctuations occurred on two timescales:<br />
* slow electric drifts, due to thermal changes in the power supply, in the RF amplifiers, and in the detector diodes;<br />
* fast and sudden electric instabilities, arising in the warm electronics or from electromagnetic interference effects, and affecting both the cold amplifiers and the warm detector diodes.<br />
<br />
The effect of slow drifts is suppressed by the pseudo-correlation architecture of the differential radiometers. Fast electric changes produce quasi-random fluctuations and abrupt steep drops or jumps in the signal. If jumps are caused by instabilities in the front-end bias voltage then the effect involves the output voltage of both diodes in the radiometer. When the jumps occur in the back-end detector diodes (so-called “pop-corn noise”) they impact only the output voltage of the corresponding diode, affecting sky and reference load samples. In both cases the differenced signal is largely immune from these effects.<br />
<br />
<br />
===1-Hz spikes===<br />
<br />
TBW<br />
<br />
An effect at 1 Hz is caused by pickup from the housekeeping electronics clock that occurs in the chain after the detector diodes and before the ADC converters {{PlanckPapers|planck2011-1-4}}{{BibCite|meinhold2009}}{{PlanckPapers|mennella2010}}. This spurious signal is detected in the radiometer time-domain outputs as a 1-s square wave with a rising edge near 0.5 s and a falling edge near 0.75 s in on-board time. In the frequency domain it appears at multiples of 1 Hz.<br />
Frequency spikes are present at some level in the output from all detectors, but affect the 44 GHz data most strongly because of the low voltage output and high post-detection gain values in that channel. For this reason spikes are removed from the 44 GHz time-ordered data via template fitting, as described in {{PlanckPapers|planck2013-p02}}.<br />
<br />
<br />
===Main beam ellipticity===<br />
TBW<br />
<br />
===Near sidelobe pickup===<br />
TBW<br />
<br />
==Effects dependent on sky signal==<br />
===Sidelobe pick-up===<br />
<br />
TBW<br />
<br />
<br />
Straylight contamination arises from the spurious signal pickup from the telescope far sidelobes. The main sources of straylight contamination are the Galaxy, especially at 30 GHz, and the cosmological dipole, mainly detected in the directions of the main reflector and sub-reflector spillover. In principle we should also include the straylight contribution from the orbital dipole, but its effect is about a factor ten lower than the cosmic dipole so that it can safely be neglected in this framework (although it has been considered in the calibration pipeline). Further details about the Planck optical system are reported in {{PlanckPapers|tauber2010b}} and the LFI beam properties are provided in {{PlanckPapers|sandri2010}}.<br />
<br />
Straylight impacts the measured signal essentially in two ways: (i) through direct contamination and coupling with the main beam sky signal; and (ii) in the photometric calibration of the radiometer detected signal. The impact on calibration and the adopted mitigation strategies are described in {{PlanckPapers|planck2013-p02b}}.<br />
Because of the beam orientation, the straylight fingerprint is different in odd surveys compared to even surveys. The Galaxy, for example, is detected by the sub-reflector spillover in the odd surveys and by the main reflector spillover in the even surveys. Because the sub-reflector spillover points approximately in the main beam direction, the Galaxy straylight pattern is close to the Galactic plane. The main spillover, instead, points at about 85&deg; from the main beam so that the Galaxy is re-imaged onto a ring.<br />
<br />
<br />
===ADC nonlinearity===<br />
<br />
TBW<br />
<br />
The linearity of analogue-to-digital converters (ADC) requires that the voltage step sizes between successive binary outputs are<br />
constant over the entire input dynamic range. If these steps are not constant we have a nonlinearity in the ADC response that leads to calibration errors.<br />
<br />
The typical fingerprint of ADC non linearity is a variation of the detector voltage output white noise that is not matched by a detectable variation in the voltage level. This effect was observed in the LFI radiometer data for the first time in flight, where drops of a few percent were observed in the voltage white noise, but not in the output level over, periods of few weeks. <br />
The typical amplitude of the region where the nonlinearity occurs is of the order of 1 mV, corresponding to about three bits in the ADC. The ADC effect is strongest (3% to 6%) in the 44 GHz channels, because of their lower detector voltages. The ADC nonlinearity effect has been characterized from flight data and removed from the TOIs according to the procedure described in the main LFI data processing paper {{PlanckPapers|planck2013-p02}}.<br />
<br />
<br />
<br />
===Imperfect photometric calibration===<br />
<br />
<br />
An important set of systematic effects are those related to the photometric calibration of the radiometers. Such effects are discussed at length in {{PlanckPapers|planck2013-p05}}. There are three different kinds of systematic effects that can affect the calibration.<br />
<br />
* Incorrect assumptions regarding the calibration signal. In the case of LFI, the signal used for the calibration is the dipolar field caused by the motion of the Solar System with respect to the CMB rest frame and by the motion of the spacecraft around the Sun. We model the former using the values quoted by Ref. {{BibCite}} and the latter using the spacecraft’s attitude information. Any error in the numbers would directly lead to an error in the calibration of Planck-LFI data.<br />
* Incorrect treatment of the calibration signal. To actually use any previous knowledge of the CMB dipole, we need to convolve the signal with the beam response of each LFI radiometer. Any error in this step would produce a systematic effect in the map, not only because of the incorrect shape expected for the calibration signal, but also because of the removal of the (wrong) dipole from the calibrated maps performed by the Planck-LFI pipeline {{PlanckPapers|planck2013-p02}}. Possible types of errors include: systematic errors in Planck’s dipole estimate; wrong convolution of the expected dipole with the radiometer beams; and incorrect masking of the Galaxy when fitting the observed signal with the dipole.<br />
* Incorrect reconstruction of gain fluctuations. Some of the algorithms adopted in calibrating LFI data for this release use the radiometer equation and the recorded variations of the radiometer total-power output to track gain changes. In principle, any deviation in the behaviour of the radiometer from the ideal case (e.g., ADC nonlinearities) can therefore induce systematic effects in the gain curves.<br />
<br />
<br />
<br />
===Pointing effects===<br />
<br />
TBW<br />
<br />
<br />
Pointing uncertainties are translated into uncertainties in pixel temperature measurements. If pointing uncertainties are not constant in time then the statistics of the sky anisotropy measurements are not preserved, with a consequent impact on the power spectrum and cosmological parameters. In Planck-LFI pointing uncertainties arise from two distinct sources.<br />
* Satellite pointing determination. The Planck Attitude Control Movement System guarantees a pointing accuracy of approximately 2′′ {{PlanckPapers|planck2013-p01}}, which is well within scientific requirements. However, small non-idealities in the system and errors in the attitude reconstruction caused, for example, by thermoelastic effects, can still affect the data.<br />
* Uncertainties in the focal plane geometry reconstruction. The measurement of the LFI focal plane geometry is based on the determination of the beam pointing with respect to the nominal line of sight, exploiting observations of Jupiter. The peak of each beam was determined by fitting data with a bivariate Gaussian function, which may be not be precisely equivalent to the real beam centre.<br />
<br />
<br />
<br />
===Polarization angle uncertainty===<br />
TBW<br />
<br />
===Ortho-mode transducer cross-polarization===<br />
TBW<br />
<br />
--><br />
<br />
== References ==<br />
<br />
<References /><br />
<br />
<br />
<br />
[[Category:LFI data processing|005]]</div>Azaccheihttps://wiki.cosmos.esa.int/planck-legacy-archive/index.php?title=LFI_systematic_effect_uncertainties&diff=14056LFI systematic effect uncertainties2018-07-06T09:32:27Z<p>Azacchei: /* Overview */</p>
<hr />
<div>{{DISPLAYTITLE:Systematic effect uncertainties}}<br />
== Overview ==<br />
<br />
Known systematic effects in the Planck-LFI data can be divided into two broad categories: effects independent of the sky signal, which can be considered as additive or multiplicative spurious contributions to the measured timelines, and effects which are dependent on the sky and that cannot be considered independently from the observation strategy.<br />
<br />
Here we report a brief summary of these effects, all the details can be found in {{PlanckPapers|planck2013-p02a}} and {{PlanckPapers|planck2014-a04||Planck-2015-A04}}.<br />
Systematic error budget remains essentially unchanged from the 2015 release see {{PlanckPapers|planck2016-l02}} for futher details.<br />
<br />
==Summary of uncertainties due to systematic effects==<br />
In this section we provide a top-level overview of the uncertainties due to systematic effects in the Planck-LFI CMB temperature maps and power spectra. Table 1 provides a list of these effects with short indications of their cause, strategies for removal and references to sections and/or papers where more information is found.<br />
<br />
{| border="1" cellspacing="0" cellpadding="2" align="center"<br />
|+ <small>'''Table 1. List of known instrumental systematic effects in Planck LFI.'''</small><br />
|-<br />
!scope="col"| Effect <br />
!scope="col"| Source <br />
!scope="col"| Control/Removal<br />
!scope="col"| Reference<br />
|-<br />
!width="280" | Effects independent of sky signal (T and P)<br />
|width="220" |<br />
|width="220" |<br />
|width="140" |<br />
|-<br />
|width="280" | White noise correlation<br />
|width="220" | Phase-switch imbalance<br />
|width="220" | Diode weighting<br />
|width="140" | {{PlanckPapers|planck2013-p02a}} {{PlanckPapers|planck2014-a04||Planck-2015-A04}}<br />
|-<br />
|width="280" | 1/<i>f</i> noise<br />
|width="220" | RF amplifiers<br />
|width="220" | Pseudo-correlation and destriping<br />
|width="140" | {{PlanckPapers|planck2013-p02a}} {{PlanckPapers|planck2014-a04||Planck-2015-A04}}<br />
|- <br />
|width="280" | Bias fluctuations <br />
|width="220" | RF amplifiers, back-end electronics&<br />
|width="220" | Pseudo-correlation and destriping <br />
|width="140" | {{PlanckPapers|planck2014-a03||Planck-2015-A03}}<br />
|- <br />
|width="280" | Thermal fluctuations<br />
|width="220" | 4-K, 20-K and 300-K thermal stages<br />
|width="220" | Calibration, destriping<br />
|width="140" | {{PlanckPapers|planck2014-a03||Planck-2015-A03}}<br />
|- <br />
|width="280" | 1-Hz spikes<br />
|width="220" | Back-end electronics<br />
|width="220" | Template fitting and removal<br />
|width="140" | {{PlanckPapers|planck2014-a03||Planck-2015-A03}}<br />
|-<br />
!width="280" | Effects dependent on sky signal (T and P)<br />
|width="220" |<br />
|width="220" |<br />
|width="140" |<br />
|-<br />
|width="280" | Main beam ellipticity<br />
|width="220" | Main beams<br />
|width="220" | Accounted for in window function<br />
|width="140" | {{PlanckPapers|planck2014-a03||Planck-2015-A03}}<br />
|-<br />
|width="280" | Near sidelobes pickup<br />
|width="220" | Optical response at angles 5&deg; from the main beam<br />
|width="220" | Masking of Galaxy and point sources<br />
|width="140" | {{PlanckPapers|planck2014-a03||Planck-2015-A03}}<br />
|-<br />
|width="280" | Far sidelobes pickup<br />
|width="220" | Main and sub-reflector spillovers<br />
|width="220" | Model sidelobes removed from timelines <br />
|width="140" | {{PlanckPapers|planck2014-a03||Planck-2015-A03}}<br />
|-<br />
|width="280" | Analogue-to-digital converter nonlinearity<br />
|width="220" | Back-end analogue-to-digital converter<br />
|width="220" | Template fitting and removal <br />
|width="140" | {{PlanckPapers|planck2014-a03||Planck-2015-A03}}<br />
|-<br />
|width="280" | Imperfect photometric calibration<br />
|width="220" | Sidelobe pickup, radiometer noise temperature changes and other non-idealities<br />
|width="220" | Calibration using the 4-K reference load voltage output<br />
|width="140" | {{PlanckPapers|planck2014-a03||Planck-2015-A03}}<br />
|-<br />
|width="280" | Pointing <br />
|width="220" | Uncertainties in pointing reconstruction, thermal changes affecting focal plane geometry<br />
|width="220" | Negligible impact anisotropy measurements<br />
|width="140" | {{PlanckPapers|planck2014-a03||Planck-2015-A03}}<br />
|-<br />
!width="280" | Effects specifically impacting polarization<br />
|width="220" |<br />
|width="220" |<br />
|width="140" |<br />
|-<br />
|width="280" | Bandpass asymmetries<br />
|width="220" | Differential orthomode transducer and receiver bandpass response<br />
|width="220" | Spurious polarization removal<br />
|width="140" | {{PlanckPapers|planck2014-a03||Planck-2015-A03}}<br />
|-<br />
|width="280" | Polarization angle uncertainty<br />
|width="220" | Uncertainty in the polarization angle in-flight measurement<br />
|width="220" | Negligible impact<br />
|width="140" | {{PlanckPapers|planck2014-a03||Planck-2015-A03}}<br />
|-<br />
|width="280" | Orthomode transducer cross-polarization<br />
|width="220" | Imperfect polarization separation <br />
|width="220" | Negligible impact <br />
|width="140" | {{PlanckPapers|planck2014-a03||Planck-2015-A03}}<br />
|-<br />
|}<br />
<br />
The impact of 1/<i>f</i> noise has been assessed using half-ring noise maps normalized to the white noise estimate at each pixel (obtained from the white noise covariance matrix), so that a perfectly white noise map would be Gaussian and isotropic with unit variance. Deviations from unity trace the contribution of residual 1/<i>f</i> noise in the final maps, which ranges from 0.06% at 70 GHz to 2% at 30 GHz.<br />
Pixel uncertainties due to other systematic effects have been calculated on simulated maps degraded to <i>N</i><sub>side</sub> = 128 at 30 and 44 GHz and <i>N</i><sub>side</sub> = 256 at 70 GHz, in order to approximate the optical beam size. This downgrading has been applied in all cases that a systematic effect has been evaluated at map level.<br />
<br />
In Table 2 we list the rms and the difference between the 99% and the 1% quantities in the pixel value distributions. For simplicity we refer to this difference as the "peak-to-peak" (p-p) difference, although it neglects outliers but effectively approximates the peak-to-peak variation of the effect on the map.<br />
<br />
<center><br />
<small>'''Table 2. Summary of systematic effects uncertainties on maps in μK<sub>CMB</sub> units.'''</small><br />
</center><br />
<br />
{| border="0" cellspacing="0" cellpadding="2" align="center"<br />
|width="450"| <center>'''30 GHz'''</center> <br />
|-<br />
|width="450"| [[File:Selection_263.png|450px]]<br />
|-<br />
|width="450"| <center>'''44 GHz'''</center> <br />
|-<br />
|width="450"| [[File:Selection_261.png|450px]]<br />
|-<br />
|width="450"| <center>'''70 GHz'''</center> <br />
|-<br />
|width="450"| [[File:Selection_262.png|450px]]<br />
|}<br />
<br />
Angular power spectra have been obtained from full resolution (<i>N</i><sub>side</sub> = 1024) systematic effect maps at each frequency using the HEALPix Anafast routine {{BibCite|gorski2005}}. In Fig. 1 we show the power spectrum of the various effects compared with the Planck best-fit spectra and with the noise level coming from the half-ring difference maps. <br />
<br />
Our assessment shows that the global impact of systematic effect uncertainties in the LFI do not limit either temperature or <i>E</i>-mode spectrum measurements.<br />
<center><br />
[[File:Selection_264.png|900px]]<br />
<br />
[[File:Selection_265.png|900px]]<br />
<br />
[[File:Selection_266.png|900px]]<br />
<br />
<small>'''Figure 1. Angular power spectra of the various systematic effects compared to the Planck beam-filtered temperature and polarization spectra. The thick dark-grey curve represents the total contribution. The dark-green dotted curve represent the contribution from far sidelobes that has been removed from the data and, therefore not considered in the total. The CMB <i>TT</i> and <i>EE</i> curves correspond to the Planck best-fit power spectra. The theoretical <i>B</i>-mode CMB spectrum assumes a tensor-to-scalar ratio <i>r</i> = 0.1, a tensor spectral index <i>n</i><sub>T</sub>=0 and has not been beam-filtered. ''Rows'': 30, 44 and 70 GHz spectra. ''Columns'': temperature, <i>E</i>-mode and <i>B</i>-mode spectra. .'''</small><br />
</center><br />
<br />
==Detailed description of the various effects==<br />
<br />
A detailed description of the impact of the various effects is conained in the paper {{PlanckPapers|planck2014-a04||Planck-2015-A04}} and details will also be updated in this supplement.<br />
<br />
<br />
<!--<br />
<br />
A detailed description of the impact of the various effects is conained in the paper being prepared for the submission of a dedicated paper to A&A and will also appear in this supplement. We expect it to be available by the end of February.<br />
<br />
<br />
==Effects independent of sky signal==<br />
===Noise correlations and 1/<i>f</i> noise===<br />
TBW<br />
<br />
<br />
As described in Ref. {{BibCite|seiffert2002}} and {{PlanckPapers|planck2011-1-4}}, imperfect matching of components generates isolation between the complementary diodes of a receiver between −10 and −15 dB. This imperfect isolation leads to a small anti-correlated component in the white noise that is cancelled by a weighted average of the time-ordered data from the two diodes of each receiver as the first step of athe processing. This avoids the complication of tracking the anti-correlated white noise throughout the analysis.<br />
We treat the combined diode data as the raw data, and calibration, noise estimation, mapmaking etc. are performed on these combined data. The weights are determined from some initial estimates of the calibrated noise for each detector, and are kept fixed for the entire mission.<br />
<br />
We estimate the signal-subtracted noise power spectrum of each receiver on 5-day time periods. Except for specific, mostly well understood events, shorter<br />
timescale noise estimation does not produce any evident trends. For nearly all the radiometers our noise model is a very good approximation of the power spectrum. <br />
<br />
Over the course of the nominal mission, the noise is well fit by the model, with the exception of the early parts of Survey 3. During this time, thermal instabilities brought on by the switchover from the nominal to the redundant sorption cooler cause poor fits and some changes in the parameters.<br />
<br />
===Thermal effects===<br />
<br />
TBW<br />
<br />
The LFI is susceptible to temperature fluctuations in the 300-K back-end modules, in the 4-K reference loads and in the 20-K focal plane. <br />
<br />
The temperature of 70-GHz reference loads was actively controlled by a proportional-integral-derivative (PID) system and is very stable (δ<i>T</i><sub>rms</sub> ∼ 0.13 mK). Reference loads of 30 and 44 GHz channels, instead, do not benefit from active thermal control. Their temperature is consequently more unstable and susceptible to major system-level events such as, for example, the switchover to the redundant sorption cooler.<br />
<br />
The 20-K LFI focal plane temperature was measured by a sensor placed on the feedhorn flange of the LFI-28 receiver. The temperature during the first sky survey was very stable. Towards the end of the first year of operations the sorption cooler performance started to degrade and its stability was maintained with a series of controlled temperature changes. The switchover to the redundant cooler left a clear signature on all the main LFI temperatures. After this operation the level of temperature fluctuations on the focal plane increased unexpectedly, and this was later understood to be the effect of liquid hydrogen that was still present in the cold-end of the nominal cooler, because of the degraded compressor system not being able to absorb all the hydrogen that was present in the cooler line. Although this effect was later mitigated by a series of dedicated operations, most of the third sky survey suffered from a higher-than-nominal level of temperature variations.<br />
<br />
The temperature of the 300-K electronics box was measured by one of its temperature sensors. During the first sky survey the back-end temperature suffered from a 24-hour fluctuation caused by the satellite transponder that was switched on daily during contact with the ground station. After day 258 the system was left continuously on and the 24-hour modulation disappeared. This operation caused an increase of the absolute temperature level. The second temperature change that occurred corresponded to the sorption cooler switch-over operation. A yearly temperature modulation due to the satellite rotation around the Sun and a specific temperature spike need also to be considered. This was caused by an operational anomaly that caused the satellite to fail to repoint for an entire day, with a corresponding temperature increase of the warm units.<br />
<br />
Details regarding the thermal stability performance of Planck can be found in {{PlanckPapers|planck2011-1-3}}, while the susceptibility of the LFI to temperature variations is discussed in Ref. {{BibCite|terenzi2009b}}.<br />
<br />
<br />
<br />
===Bias fluctuations===<br />
<br />
TBW<br />
<br />
<br />
The signal detected by the radiometers can vary because of fluctuations in the front-end and back-end amplifier bias voltages. In the LFI these fluctuations occurred on two timescales:<br />
* slow electric drifts, due to thermal changes in the power supply, in the RF amplifiers, and in the detector diodes;<br />
* fast and sudden electric instabilities, arising in the warm electronics or from electromagnetic interference effects, and affecting both the cold amplifiers and the warm detector diodes.<br />
<br />
The effect of slow drifts is suppressed by the pseudo-correlation architecture of the differential radiometers. Fast electric changes produce quasi-random fluctuations and abrupt steep drops or jumps in the signal. If jumps are caused by instabilities in the front-end bias voltage then the effect involves the output voltage of both diodes in the radiometer. When the jumps occur in the back-end detector diodes (so-called “pop-corn noise”) they impact only the output voltage of the corresponding diode, affecting sky and reference load samples. In both cases the differenced signal is largely immune from these effects.<br />
<br />
<br />
===1-Hz spikes===<br />
<br />
TBW<br />
<br />
An effect at 1 Hz is caused by pickup from the housekeeping electronics clock that occurs in the chain after the detector diodes and before the ADC converters {{PlanckPapers|planck2011-1-4}}{{BibCite|meinhold2009}}{{PlanckPapers|mennella2010}}. This spurious signal is detected in the radiometer time-domain outputs as a 1-s square wave with a rising edge near 0.5 s and a falling edge near 0.75 s in on-board time. In the frequency domain it appears at multiples of 1 Hz.<br />
Frequency spikes are present at some level in the output from all detectors, but affect the 44 GHz data most strongly because of the low voltage output and high post-detection gain values in that channel. For this reason spikes are removed from the 44 GHz time-ordered data via template fitting, as described in {{PlanckPapers|planck2013-p02}}.<br />
<br />
<br />
===Main beam ellipticity===<br />
TBW<br />
<br />
===Near sidelobe pickup===<br />
TBW<br />
<br />
==Effects dependent on sky signal==<br />
===Sidelobe pick-up===<br />
<br />
TBW<br />
<br />
<br />
Straylight contamination arises from the spurious signal pickup from the telescope far sidelobes. The main sources of straylight contamination are the Galaxy, especially at 30 GHz, and the cosmological dipole, mainly detected in the directions of the main reflector and sub-reflector spillover. In principle we should also include the straylight contribution from the orbital dipole, but its effect is about a factor ten lower than the cosmic dipole so that it can safely be neglected in this framework (although it has been considered in the calibration pipeline). Further details about the Planck optical system are reported in {{PlanckPapers|tauber2010b}} and the LFI beam properties are provided in {{PlanckPapers|sandri2010}}.<br />
<br />
Straylight impacts the measured signal essentially in two ways: (i) through direct contamination and coupling with the main beam sky signal; and (ii) in the photometric calibration of the radiometer detected signal. The impact on calibration and the adopted mitigation strategies are described in {{PlanckPapers|planck2013-p02b}}.<br />
Because of the beam orientation, the straylight fingerprint is different in odd surveys compared to even surveys. The Galaxy, for example, is detected by the sub-reflector spillover in the odd surveys and by the main reflector spillover in the even surveys. Because the sub-reflector spillover points approximately in the main beam direction, the Galaxy straylight pattern is close to the Galactic plane. The main spillover, instead, points at about 85&deg; from the main beam so that the Galaxy is re-imaged onto a ring.<br />
<br />
<br />
===ADC nonlinearity===<br />
<br />
TBW<br />
<br />
The linearity of analogue-to-digital converters (ADC) requires that the voltage step sizes between successive binary outputs are<br />
constant over the entire input dynamic range. If these steps are not constant we have a nonlinearity in the ADC response that leads to calibration errors.<br />
<br />
The typical fingerprint of ADC non linearity is a variation of the detector voltage output white noise that is not matched by a detectable variation in the voltage level. This effect was observed in the LFI radiometer data for the first time in flight, where drops of a few percent were observed in the voltage white noise, but not in the output level over, periods of few weeks. <br />
The typical amplitude of the region where the nonlinearity occurs is of the order of 1 mV, corresponding to about three bits in the ADC. The ADC effect is strongest (3% to 6%) in the 44 GHz channels, because of their lower detector voltages. The ADC nonlinearity effect has been characterized from flight data and removed from the TOIs according to the procedure described in the main LFI data processing paper {{PlanckPapers|planck2013-p02}}.<br />
<br />
<br />
<br />
===Imperfect photometric calibration===<br />
<br />
<br />
An important set of systematic effects are those related to the photometric calibration of the radiometers. Such effects are discussed at length in {{PlanckPapers|planck2013-p05}}. There are three different kinds of systematic effects that can affect the calibration.<br />
<br />
* Incorrect assumptions regarding the calibration signal. In the case of LFI, the signal used for the calibration is the dipolar field caused by the motion of the Solar System with respect to the CMB rest frame and by the motion of the spacecraft around the Sun. We model the former using the values quoted by Ref. {{BibCite}} and the latter using the spacecraft’s attitude information. Any error in the numbers would directly lead to an error in the calibration of Planck-LFI data.<br />
* Incorrect treatment of the calibration signal. To actually use any previous knowledge of the CMB dipole, we need to convolve the signal with the beam response of each LFI radiometer. Any error in this step would produce a systematic effect in the map, not only because of the incorrect shape expected for the calibration signal, but also because of the removal of the (wrong) dipole from the calibrated maps performed by the Planck-LFI pipeline {{PlanckPapers|planck2013-p02}}. Possible types of errors include: systematic errors in Planck’s dipole estimate; wrong convolution of the expected dipole with the radiometer beams; and incorrect masking of the Galaxy when fitting the observed signal with the dipole.<br />
* Incorrect reconstruction of gain fluctuations. Some of the algorithms adopted in calibrating LFI data for this release use the radiometer equation and the recorded variations of the radiometer total-power output to track gain changes. In principle, any deviation in the behaviour of the radiometer from the ideal case (e.g., ADC nonlinearities) can therefore induce systematic effects in the gain curves.<br />
<br />
<br />
<br />
===Pointing effects===<br />
<br />
TBW<br />
<br />
<br />
Pointing uncertainties are translated into uncertainties in pixel temperature measurements. If pointing uncertainties are not constant in time then the statistics of the sky anisotropy measurements are not preserved, with a consequent impact on the power spectrum and cosmological parameters. In Planck-LFI pointing uncertainties arise from two distinct sources.<br />
* Satellite pointing determination. The Planck Attitude Control Movement System guarantees a pointing accuracy of approximately 2′′ {{PlanckPapers|planck2013-p01}}, which is well within scientific requirements. However, small non-idealities in the system and errors in the attitude reconstruction caused, for example, by thermoelastic effects, can still affect the data.<br />
* Uncertainties in the focal plane geometry reconstruction. The measurement of the LFI focal plane geometry is based on the determination of the beam pointing with respect to the nominal line of sight, exploiting observations of Jupiter. The peak of each beam was determined by fitting data with a bivariate Gaussian function, which may be not be precisely equivalent to the real beam centre.<br />
<br />
<br />
<br />
===Polarization angle uncertainty===<br />
TBW<br />
<br />
===Ortho-mode transducer cross-polarization===<br />
TBW<br />
<br />
--><br />
<br />
== References ==<br />
<br />
<References /><br />
<br />
<br />
<br />
[[Category:LFI data processing|005]]</div>Azaccheihttps://wiki.cosmos.esa.int/planck-legacy-archive/index.php?title=Map-making_LFI&diff=14055Map-making LFI2018-07-06T09:26:27Z<p>Azacchei: /* Production */</p>
<hr />
<div>==Mapmaking==<br />
The inputs to the mapmaking procedure consist of the calibrated timelines, along with the corresponding pointing information.<br />
The main output consists of temperature and polarization maps. <br />
An important part of the mapmaking step is the removal of correlated 1/<i>f</i> noise.<br />
<br />
LFI maps were constructed with the MADAM mapmaking code, version 3.7.4.<br />
The code is based on a generalized destriping technique, where the correlated noise component is modelled as a sequence of constant offset "baselines". <br />
The baseline solution is constrained by a noise filter.<br />
As auxiliary information, the code produces a hit-count map and a white noise covariance matrix.<br />
No beam information is used, with the signal being simply assigned to the pixel where the centre of the beam falls.<br />
<br />
The chosen baseline length was 1s for the 44GHz and 70GHz maps, 0.25s for the 30GHz map. This gives good noise removal,<br />
without being computationally burdensome.<br />
The noise filter was built according to the noise parameters (see noise section).<br />
Flagged samples were excluded from the analysis. The Galaxy region was masked out in the destriping phase, to reduce errors arising from strong signal gradients. Radiometers were combined according to the horn-uniform weighting scheme to minimize systematics. The polarization component was included in the analysis and is part of this release.<br />
A detailed description of the mapmaking procedure is given in {{PlanckPapers|planck2013-p02}}, {{PlanckPapers|planck2014-a03}}, {{PlanckPapers|planck2014-a07}} no relevant changes has been applyed in the 2018 release. See also the section on [[Frequency Maps]].<br />
<br />
The maps are in HEALPix format, at resolution <i>N</i><sub>side</sub>=1024 for all frequencies with an additional map at <i>N</i><sub>side</sub>=2048 for the LFI 70GHz channel, in the nested pixelization scheme.<br />
Unobserved pixels are marked by a special value.<br />
<br />
The released maps are in Galactic coordinates.<br />
The conversion between ecliptic and Galactic coordinates is described by the rotation matrix<br />
<math><br />
\newcommand{\Re}{\mathrm{Re}\,}<br />
\newcommand{\pFq}[5]{{}_{#1}\mathrm{F}_{#2} \left( \genfrac{}{}{0pt}{}{#3}{#4} \bigg| {#5} \right)}<br />
</math><br />
<br />
:<math> <br />
\begin{align}<br />
\label{def:Rot_matrix}<br />
\left (\begin{matrix}<br />
-0.054882486 & 0.494116468 & -0.867661702\\ <br />
-0.993821033 & -0.110993846 & -0.000346354\\ <br />
-0.096476249 & 0.86228144 & 0.497154957 <br />
\end{matrix} \right).<br />
\end{align} <br />
</math> <br />
The conversion was applied to the input pointing data, prior to the construction of the map.<br />
<br />
==Low-resolution maps and noise covariance matrices==<br />
<br />
To fully exploit the information contained in the large-scale structure of the microwave sky, pixel-pixel covariances are needed in the maximum likelihood estimation of the CMB power spectrum. However, full covariance matrices are impossible to employ at the native map resolution due to resource limitations. A low-resolution data set is therefore required for the low-&#8467; analysis. This data set has been packed into three different files, one per frequency, called "LFI_NoiseCovMat_0??_0016_R3.00.tgz", that can be downloaded from the Cosmology section of the Planck Legacy Archive. <br />
They consist of low-resolution maps, and descriptions of residual noise present in those maps given by pixel-pixel noise covariance matrices (NCVMs).<br />
Note the in the 2018 release the Low-resolution maps full mission coverage, excluding Surveys 2 and 4 has not been used. We release them for crosschecking purposes with respect 2015 release.<br />
<br />
{| border="1" cellpadding="3" cellspacing="0" align="center" style="text-align:left" width=800px<br />
|+ Contents of '''LFI_NoiseCovMat_0??_0016_R3.00.tgz'''<br />
|- bgcolor="ffdead"<br />
! Filenames || Comment<br />
|- <br />
| LFI_SkyMap_0??_0016_nobs_DX12_full_regnoise.fits || Low-resolution maps. Full mission coverage.<br />
|- <br />
| LFI_SkyMap_0??_0016_nobs_DX12_Corrected_full_regnoise.fits || Low-resolution maps BandPass Corrected. Full mission coverage. Corrected for the BandPass.<br />
|- <br />
| LFI_SkyMap_0??_0016_nobs_DX12_s1-s3-s5-s6-s7-s8_regnoise.fits || Low-resolution maps. Full mission coverage, excluding Surveys 2 and 4. <br />
|- <br />
| LFI_SkyMap_0??_0016_nobs_DX12_Corrected_s1-s3-s5-s6-s7-s8_regnoise.fits || Low-resolution maps. Full mission coverage, excluding Surveys 2 and 4. Corrected for the BandPass.<br />
|- <br />
| offset_covmat_toast_nside64T16_nobs_025sec_??GHz_DX12_full_bin.dat || Low-resolution noise covariance matrices. Regularization noise added. Format: C unformatted.<br />
|- <br />
| offset_covmat_toast_nside64T16_nobs_025sec_??GHz_DX12_s1-s3-s5-s6-s7-s8_bin.dat || Low-resolution noise covariance matrices. Regularization noise added. Format: C unformatted.<br />
|- <br />
| covmat_toast_nside64T16_nobs_025sec_??GHz_DX12_full_bin.dat || Low-resolution noise covariance matrices. No regularization noise added. Format: C unformatted.<br />
|- <br />
| covmat_toast_nside64T16_nobs_025sec_??GHz_DX12_s1-s3-s5-s6-s7-s8_bin.dat || Low-resolution noise covariance matrices. No regularization noise added. Format: C unformatted.<br />
|- <br />
|}<br />
<br />
<br />
<br />
The low-resolution data set can currently be utilized efficiently only at resolution <i>N</i><sub>side</sub> = 16, or lower. All the low-resolution data products are produced at this target resolution.<br />
===Low-resolution maps===<br />
A number of different schemes to obtain the low-resolution maps are discussed in {{BibCite|keskitalo2013}}. We chose to downgrade the maps using the inverse noise weighting, no changes on the procedure has been applyed to the 2018 release. This is discussed further in {{PlanckPapers|planck2013-p02}} {{PlanckPapers|planck2014-a07}}.<br />
====Inputs====<br />
We took the high-resolution maps described in [[Map-making LFI#Map-making|Map-making]] and [[Frequency Maps]], and the corresponding 3&times;3 matrices as an input for this analysis step.<br />
<br />
====Production====<br />
The high-resolution maps were downgraded to <i>N</i><sub>side</sub> = 16 using inverse noise weights (given by the 3&times;3 matrices), and subsequently the temperature part was smoothed with a symmetric Gaussian beam with FWHM = 440arcmin.<br />
<br />
===Noise covariance matrices===<br />
<br />
The statistical description of the residual noise in the maps is given in the form of a pixel-to-pixel noise covariance matrix (NCVM), as described in {{BibCite|keskitalo2013}}. <br />
<br />
====Inputs====<br />
<br />
The noise model was determined by three noise parameters: the white noise level &sigma;; slope; and knee frequency <i>f</i><sub>knee</sub>. We actually used three sets of noise parameters, one for the entire mission (noise parameters are listed in Table 1), and one for each sky survey (SS1 and SS2).<br />
<br />
We used the same pointing as in the noise Monte Carlo simulations. See the description in [[Map-making LFI#Noise Monte Carlo Simulation#Inputs|Noise Monte Carlo Simulation Inputs]].<br />
<br />
We used the gap files produced during the making of the flight maps to leave out samples that were flagged as bad for various reasons.<br />
<br />
====Production====<br />
<br />
The output of the NCVM module of MADAM mapmaker are inverse NCVMs. Since the inverse matrices are additive, we divided the computations into a number of small chunks to save computational resources. We first calculated one inverse NCVM per radiometer per survey at resolution <i>N</i><sub>side</sub>=32, and then combined these individual inverse matrices to form the actual inverse matrices. The mapmaking parameters were almost identical to the standard mapmaking runs. The differing parameter values are listed below:<br />
* baseline lengths were 0.25s for 30GHzand 1.0s for 44GHz, and 70GHz;<br />
* the calculations were performed at resolution <i>N</i><sub>side</sub> = 64;<br />
* no destriping mask was applied;<br />
* the horns were weighted optimally.<br />
<br />
To obtain the noise covariance from its inverse, the matrices are inverted using the eigen decomposition of a matrix. The monopole of the temperature map cannot be resolved by the mapmaker, and thus the matrix becomes singular. This ill-determined mode is left out of the analysis.<br />
<br />
Having calculated the eigen decomposition in the previous step, we can apply the same linear operators to modify the eigenvectors as were applied to the high-resolution maps while downgrading them. The eigenvectors are downgraded to <i>N</i><sub>side</sub> = 16 using inverse noise weights, and subsequently the temperature part is smoothed with a symmetric Gaussian beam with FWHM = 440arcmin.<br />
<br />
The final matrices are then recomposed from the original eigenvalues and modified eigenvectors.<br />
<br />
The low-resolution noise covariance matrices:<br />
* are C binary format files;<br />
* are organized in block form,<br />
<math><br />
\newcommand{\Re}{\mathrm{Re}\,}<br />
\newcommand{\pFq}[5]{{}_{#1}\mathrm{F}_{#2} \left( \genfrac{}{}{0pt}{}{#3}{#4} \bigg| {#5} \right)}<br />
</math><br />
<math><br />
\begin{align}<br />
\label{def:Block_form}<br />
\left (\begin{matrix}<br />
II & IQ & IU \\<br />
QI & QQ & QU \\<br />
UI & UQ & UU<br />
\end{matrix} \right);<br />
\end{align} <br />
</math><br />
<br />
* are in the HEALPix nested pixelisation scheme (with resolution is <i>N</i><sub>side</sub> = 16, and thus there are <i>N</i><sub>pix</sub> = 3072 pixels);<br />
* are in Galactic coordinates;<br />
* have K<sub>CMB</sub> units.<br />
<br />
==Half-ring jackknife noise maps==<br />
<br />
===Overview===<br />
In the 2018 release we follow the same procedure as in {{PlanckPapers|planck2014-a03||Planck-2015-A03}} in order to estimate the noise directly at the map level and in the angular power spectra.<br />
<br />
Briefly, instead of using the full time-ordered data as described above, we produced two sets of maps using either only the first half of each pointing period (map named <b>j</b><sub>1</sub> below) or only the second half of each pointing period (map named <b>j</b><sub>2</sub>). At each pixel <i>p</i>, these half-ring jackknife maps <b>j</b><sub>1</sub> and <b>j</b><sub>2</sub> contain the same sky signal, since they result from the same scanning pattern on the sky. However, because of instrumental noise, the maps <b>j</b><sub>1</sub> and <b>j</b><sub>2</sub> are not identical.<br />
<br />
We estimated the noise level in each map <b>m</b> made using the full (ring) data, by constructing a half-ring difference map<br />
<br />
<math>\mathbf{n_{m}}(p) = [ \mathbf{j_1}(p) - \mathbf{j_2}(p)] \ / \ \mathbf{w_{\rm hit}}(p)\,,</math><br />
<br />
with weights<br />
<br />
<math>\mathbf{w_{hit}}(p) = \sqrt{ \mathbf{hit_{full}}(p) \left[ \frac{1}{\mathbf{hit_1}(p)} +<br />
\frac{1}{\mathbf{hit_2}(p)} \right]}\,</math>.<br />
<br />
Here <b>hit</b><sub>full</sub>(<i>p</i>) = <b>hit</b><sub>1</sub>(<i>p</i>) + <b>hit</b><sub>2</sub>(<i>p</i>)<br />
is the hit count at pixel <i>p</i> in the full map <b>m</b>, while <b>hit</b><sub>1</sub> and <b>hit</b><sub>2</sub> are the hit counts of <b>j</b><sub>1</sub> and <b>j</b><sub>2</sub>, respectively. The weight factor <b>w</b><sub>hit</sub>(<i>p</i>) is equal to 2 only in those pixels where <b>hit</b><sub>1</sub>(<i>p</i>) = <b>hit</b><sub>2</sub>(<i>p</i>) . In a typical pixel, <b>hit</b><sub>1</sub>(<i>p</i>) will differ slightly from<br />
<b>hit</b><sub>2</sub>(<i>p</i>) and hence the weight factor is <b>w</b><sub>hit</sub>(<i>p</i>)>2.<br />
<br />
The half-ring difference maps <b>n</b><sub>m</sub> are the most direct measure of the noise in the actual maps. The other noise estimates (NCVM and noise Monte Carlo) rely on specific modelling of the noise and this modelling can be validated by comparing to the half-ring difference maps. However, the half-ring difference maps can only capture the noise that varies faster than half of the duration of the pointing period, i.e., the noise whose frequency is approximately <i>f</i> > 1/20min = 0.85mHz.<br />
<br />
We calculated the noise maps <b>n</b><sub>m</sub>, from half-ring "jackknife" maps for temperature (<i>I</i>) and polarization (<i>Q</i> and <i>U</i>) and as a first quality check of the maps (and as one of the tests of the whole data processing pipeline up to the map level) tested both numerically and visually that these noise maps divided pixel-by-pixel by the square root of the white noise covariance maps were approximately Gaussian with variance near to unity. Temperature noise maps for the nominal survey and for the first and second sky surveys are shown in the next subsection. Furthermore we calculated from the noise maps the temperature and polarization (E and B mode) auto-correlation and cross-correlation noise angular power spectra using HEALPix anafast and compared to these the results from the white noise covariance matrices and from the noise Monte Carlo simulations. A similar comparison was made between downgraded half-ring noise maps, downgraded noise Monte Carlo maps, and the low-resolution noise covariance maps. Detailed results are presented in {{PlanckPapers|planck2016-l02}}.<br />
<br />
===Comparison of noise estimates using Half-Ring===<br />
<br />
Here we compare noise angular power spectra estimated from half-ring difference maps (red), white noise covariance maps (black dash-dotted lines), and 100 full noise Monte Carlo simulations (grey band showing range for 16th and 84th quantiles of noise simulations, and the black solid lines giving the median, i.e., 50th quantile, of distributions). See the next section for details of noise Monte Carlo simulations. From top to botto we show ''TT'', ''EE'' and ''BB'' power spectra for 30 GHz (left), 44 GHz (centre), and 70 GHz (right). Half-ring spectra are binned with <math>\mathbf{\Delta}l = 25 </math> for <math> l \mathbf{\geq} 75 </math>.<br />
<br />
[[File:test_ffp10.png|thumb|800px|center|<b>Consistency Check</b>]]<br />
<br />
Below the null-tests comparing power spectra from survey differences to those from teh half-ring maps are showed. Difefrences are: left, Survey 1 - Survey 2; Middle , Survey 1- Survey 3; and right, Survey 1 - Survey4. these are for 30 GHz (top), 44 GHz (middle), and 70 GHz (bottom), for both ''TT'' and ''EE'' power spectra. There is a significant improvement in Surve1 - Survey 2 and Survey 1 - Survey 4 at 30 GHz, especially in ''EE''. See {{PlanckPapers|planck2016-l02}} for further details.<br />
<br />
[[File:nullhr1517.png|thumb|800px|center|<b>Null Test</b>]]<br />
<br />
<br />
====High-ell average noise relative to white noise estimate====<br />
<br />
The figure below is the same as the previous figures, but here the noise comparison is made from the high &#8467; tails of the angular power spectra, where the white noise dominates. We have taken the average of <i>C</i><sub>&#8467;</sub> from multipoles between 1150 and 1800 for both temperature and polarization and tehn comparing with the WNCVM. As already shown in previous releases, there is still an excess of 1/f noise, meaning tha both the real data and the noise MCs predict slightly larger noise than the WNCVM. It is important to note that such noise excess is reduced considerably with respect to the 2015 release.<br />
<br />
[[File:high.png|thumb|800px|center|<b>Ratio at high multipoles</b>]]<br />
<br />
==Noise Monte Carlo simulations==<br />
<br />
===Overview===<br />
Calculating and handling full pixel-to-pixel noise covariance matrices for Planck maps if feasible only at low resolution.<br />
To support the analysis of high-resolution maps, a Monte Carlo set of noise maps were produced. These maps were produced from noise timelines using the same map-making procedure as for the flight data. In the noise Monte Carlo it was possible to follow exactly the mapmaking procedure used for the flight maps, whereas for the calculation of noise covariance matrices some approximations had to be made.<br />
Such noise Monte Carlos were produced at two levels of the analysis: (1) LFI Monte Carlo (MC) as part of the LFI data processing procedure; and (2) Full Focal Plane (FFP) Monte Carlos as part of the joint HFI/LFI data processing. This page describes the LFI noise MCs. For the FFP MC, see [[HL-sims]] and [[Simulation data]].<br />
<br />
===Inputs===<br />
The noise MC uses a three-parameter noise model, consisting of white noise level (&sigma;), slope, and knee frequency (<i>f</i><sub>knee</sub>)). Here the noise consists of white noise and correlated 1/<i>f</i> noise, with a power spectrum<br />
<br />
:<math> P(f) = \frac{2\sigma^2}{f_\mathrm{sample}}\left(\frac{f}{f_\mathrm{knee}}\right)^\mathrm{slope} </math>,<br />
<br />
where <i>f</i><sub>sample</sub> is the sampling frequency of the instrument. The noise parameters were determined separately for each radiometer, as described in the section [[TOI processing LFI#Noise| Noise]] above, assuming they stayed constant over the mission. <br />
<br />
The detector pointing was reconstructed from satellite pointing information, focal-plane geometry, pointing correction (tilt angle), and sample timing, using Level-S simulation software. The same pointing solution (two focal planes) was used as for the LFI flight maps. Due to numerical accuracy, the detector pointing in the noise MC was not exactly the same as for the flight maps, so some data samples (of the order of one in a thousand) whose pointing was near the pixel boundary ended up assigned to the neighbouring pixel. During mapmaking from the flight data, a "gap file" was produced to represent the samples that were omitted from mapmaking due to various flags. This gap file was used in the noise MC instead of the full set of flags. The flight mapmaking procedure used destriping masks to prevent regions of strong signal gradients from contributing to the noise baseline solution. These same destriping masks (one for each frequency channel) were used for the noise MC.<br />
<br />
===Production===<br />
The noise was generated internally in the Madam mapmaking code using a stochastic differential equation (SDE) method, to avoid time-consuming writing and reading of noise timelines to and from disk. Noise for each pointing period was generated separately, using a double-precision random number seed constructed from the realization number, radiometer number, and the pointing period number; this allowed for regeneration of the same noise realization when needed. White noise and 1/<i>f</i> noise were generated separately. <br />
<br />
The same mapmaking code (Madam) with the same parameter settings was used for the noise MC as for the flight maps.<br />
In addition to the destriped maps from the full noise (output maps), binned maps from just the white noise (binned white noise maps) were produced; they represent the white noise part of the output maps. The difference between these two maps represents the residual correlated noise in the output map. The maps were made at HEALPix resolution <i>N</i><sub>side</sub> = 1024 for all LFI frequency channels and also at HEALPix resolution <i>N</i><sub>side</sub> = 2048 for the 70 GHz channel.<br />
For low-resolution analysis, these maps were downgraded (and the temperature part was smoothed) to <i>N</i><sub>side</sub> = 32 and <i>N</i><sub>side</sub> = 16.<br />
<br />
In addition to frequency maps for the nominal survey, also single-survey and 70 GHz horn-pair maps were produced in the noise MC. For each case 102-1026 realizations were produced.<br />
<br />
===Usage===<br />
<br />
These noise Monte Carlo maps were used for a number of purposes in LFI data analysis. They were compared to the low-resolution noise covariance matrices, generated for the same noise model, in order to reveal the impact of the approximations in the noise covariance matrix calculation. They were compared to the half-ring noise maps to see how well the noise model matches the noise in the flight maps (noting, however, that the half-ring noise maps misrepresent the lowest noise frequencies in the flight maps, and contain some effects from the sky signal). They were also used in power spectrum estimation and non-Gaussianity estimation.<br />
<br />
===Examples===<br />
<br />
As an example, we show below images of the first realization of the 70GHz frequency map noise for the nominal survey. The images are in the order: destriped full noise; binned white noise; and residual correlated noise. Note that it is difficult to see any difference between the first two images, since the residual correlated noise is more than an order of magnitude below the white noise level. The units here are K<sub>CMB</sub>. <br />
<br />
<br />
<br />
[[File:LFI_4_5_5_4_madam_mask_1sec_DB10_1_noise_70GHz_all_DX9delta_nom_1024outmap.00000.gif|thumb|800px|center|<b>Destriped full noise.</b>]]<br />
[[File:LFI_4_5_5_4_madam_mask_1sec_DB10_1_white_70GHz_all_DX9delta_nom_1024binmap.00000.gif|thumb|800px|center|<b>Binned white noise.</b>]]<br />
[[File:LFI_4_5_5_4_madam_mask_1sec_DB10_1_rcnoise_70GHz_all_DX9delta_nom_1024map.00000.gif|thumb|800px|center|<b>Residual correlated noise.</b>]]<br />
<br />
<br />
The following two images show the statistics of the angular power spectra of 101 realizations of the 70 GHz frequency map noise for the nominal survey. The thick black line shows the median <i>C</i><sub>&#8467;</sub>, while the green line the mean <i>C</i><sub>&#8467;</sub>. Thin black lines show the minimum, 16th percentile, 84th percentile, and the maximum <i>C</i><sub>&#8467;</sub>. The red line is the 102nd realization. The first plot is for the full noise in the output map, while the second plot is for the residual correlated noise.<br />
<br />
[[File:LFI_4_5_5_4_cl_TT_stat_noisemc101_1sec_70GHz_all_DX9delta_nom.png|thumb|800px|center|<b>Full noise.</b>]]<br />
[[File:LFI_4_5_5_4_cl_TT_stat_rcnoisemc101_1sec_70GHz_all_DX9delta_nom.png|thumb|800px|center|<b>Residual correlated noise.</b>]]<br />
<br />
==References==<br />
<br />
<br />
<References /><br />
<br />
<br />
<br />
<br />
[[Category:LFI data processing|004]]</div>Azacchei