Difference between revisions of "Single detector maps"

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[[Category:Mission science products]]
 
[[Category:Mission science products]]
  
== VERY MUCH DAFT ==
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== Introduction ==
  
===Description of the product===
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<center>
These are maps built using a single detector, and covering the full (or the nominal TBC) mission. They are produced only for the unpolarised bolometers
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{| border="1" cellspacing="10" cellpadding="8" align="center" style="background:yellow; color:maroon; font-size:150%"  width="600px"
 +
! There  are no single detector maps in the first release.  
  
===Pipeline===
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This section will serve for later releases.
Mapmaking
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|}
 +
</center>
  
===Input Data===
 
  
* Signal TOIs
 
* Destriping offsets
 
* Calibration factors (from IMO)
 
  
===Related products===
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Maps for single detectors are built for full or part of the mission and are used primarily for characterization purposes: while the ones built with an unpolarized detector have a scientific value, the ones built using a polarization sensitive one have little, since, among other things, the polarization angle varies around the sky.  Each signal map will be accompanied by a hit map and a variance map. All maps are in Healpix format, with Nside of 2048 for HFI and of  1024 for LFI, in Galactic coordinates, and Nested ordering. The three maps will be packaged into a FITS files with a single ''BINTABLE'' extension containing a table of three columns; the structure of the FITS file is given in the [[#FITS file structure | FITS file structure]] section below. 
  
Other maps
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The FITS filenames are of the form ''{H|L}FI_{detname}_nnnn_yyyymmdd_{type}_{mission}.fits'', where ''detname'' is a detector identifier, and ''nnnn'' is the Healpix Nside of the map, the optional ''type'' indicates the subset of input data used, and ''mission'' indicates the coverage period, i.e., ''full'', ''nominal'', or ''survey_n'' (TBC; an alternative of the type ''{H|L}FI_detname_{type}_{mission}_Rn.mm.fits'' is being considered, where Rn.mm is the release number).  A full list of products, by their names, is given in the [[#List of products | List of products]] below.
 +
These
  
===Data format===
 
  
These maps are delivered as FITS files containing a single extension named CH-MAP with a 3-column table containing:
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=== HFI Processing ===
  
* col 1, "I_Stokes": Intensity (units: K_cmb)
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See [[Frequency Maps#Introduction|Frequency Maps]] section
* col 2, "II_cov": variance estimate (diagonal elements of the pixel covariance matrix) on the Intensity (units: K_cmb)
 
* col 3, "Hits": Number of hits per pixel (units: none)
 
  
In accordance with ICD-031, all maps are in GALACTIC coordinates with N_side=2048.  There are 18 individual detector maps for HFI (all unpolarised detectors except for the 143-8 and 545-3 RTS bolometers) and ??? for LFI
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=== LFI PRocessing ===
 +
 
 +
TBW
 +
 
 +
 
 +
== List of products ==
 +
 
 +
=== First release ===
 +
 
 +
None
 +
 
 +
=== Second Release ===
 +
 
 +
TBW
 +
 
 +
== FITS file structure ==
 +
 
 +
The FITS file structure is like that of Intensity-only frequency maps as described in [[Frequency_Maps#FITS_file_structure | the next section]]
  
 
===Header keywords===
 
===Header keywords===

Latest revision as of 10:47, 18 October 2012


Introduction[edit]

There are no single detector maps in the first release.

This section will serve for later releases.


Maps for single detectors are built for full or part of the mission and are used primarily for characterization purposes: while the ones built with an unpolarized detector have a scientific value, the ones built using a polarization sensitive one have little, since, among other things, the polarization angle varies around the sky. Each signal map will be accompanied by a hit map and a variance map. All maps are in Healpix format, with Nside of 2048 for HFI and of 1024 for LFI, in Galactic coordinates, and Nested ordering. The three maps will be packaged into a FITS files with a single BINTABLE extension containing a table of three columns; the structure of the FITS file is given in the FITS file structure section below.

The FITS filenames are of the form {H|L}FI_{detname}_nnnn_yyyymmdd_{type}_{mission}.fits, where detname is a detector identifier, and nnnn is the Healpix Nside of the map, the optional type indicates the subset of input data used, and mission indicates the coverage period, i.e., full, nominal, or survey_n (TBC; an alternative of the type {H|L}FI_detname_{type}_{mission}_Rn.mm.fits is being considered, where Rn.mm is the release number). A full list of products, by their names, is given in the List of products below. These


HFI Processing[edit]

See Frequency Maps section

LFI PRocessing[edit]

TBW


List of products[edit]

First release[edit]

None

Second Release[edit]

TBW

FITS file structure[edit]

The FITS file structure is like that of Intensity-only frequency maps as described in the next section

Header keywords[edit]

A typical header for the extension is

XTENSION= 'BINTABLE'           / binary table extension                         
BITPIX  =                    8 / 8-bit bytes                                    
NAXIS   =                    2 / 2-dimensional binary table                     
NAXIS1  =                   12 / width of table in bytes                        
NAXIS2  =             50331648 / number of rows in table                        
PCOUNT  =                    0 / size of special data area                      
GCOUNT  =                    1 / one data group (required keyword)              
TFIELDS =                    3 / number of fields in each row                   
TTYPE1  = 'I_Stokes'           / label for field   1                            
TFORM1  = '1E8     '           / data format of field: 4-byte REAL              
TUNIT1  = 'K_CMB   '           / physical unit of field                         
TTYPE2  = 'Hits    '           / label for field   2                            
TFORM2  = '1J      '           / data format of field: 4-byte INTEGER           
TUNIT2  = 'none    '           / physical unit of field                         
TTYPE3  = 'II_cov  '           / label for field   3                            
TFORM3  = '1E8     '           / data format of field: 4-byte REAL              
TUNIT3  = '(K_CMB)^2'          / physical unit of field                         
EXTNAME = 'CH-MAP  '           / name of this binary table extension            
FREQ    = '857     '                                                            
PIXTYPE = 'HEALPIX '                                                            
COORDSYS= 'GALACTIC'                                                            
ORDERING= 'NESTED  '                                                            
FILENAME= 'HFI_857-2_2048_20120210_nominal.fits'                                
NSIDE   =                 2048                                                  
CHANNEL = '857-2   '                                                            
FIRSTPIX=                    0                                                  
LASTPIX =             50331647                                                  
EXTVER  = '1       '                                                            
PROCVER = 'v50     '                                                            
BAD_DATA= '-1.63750E+30'                                                        
COMMENT = 'Rel DR4 '                                                            
END

(Planck) High Frequency Instrument

(Planck) Low Frequency Instrument

Flexible Image Transfer Specification

To be confirmed

Cosmic Microwave background