Mapmaking and photometric calibration

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Introduction[edit]

This section gives an overview of the mapmaking and the calibration procedures used by the HFI DPC to build detector and frequency maps.

  • Procedures for the 2013 release is to be found in Planck-2013-VI[1] and Planck-2013-VIII[2] (see at the bottom of the page)
  • Procedures for the 2015 release is to be found in Planck-2015-A08[3] (see at the bottom of the page)
  • In 2016, a new mapmaking procedure SRoll has been introduced. This allowed for the first time the use of large scale polarized data and the extraction of the reionization parameter. The procedure and its results are described in Planck-2016-XLVI[4].
  • For the 2017 legacy release, the same SRoll procedure has been used to produce the frequency intensity and polarization maps. Planck-2020-A3[5] fully describes the procedures, the products and their characterization.


SRoll global solution[edit]

Inputs to the mapmaking[edit]

For the 2017 release, the TOI processing remains unchanged from the previous 2015 release (see http://wiki.cosmos.esa.int/planckpla-int/index.php/TOI_processing). Nevertheless a slight cut in the data selection has removed the data of 1000 pointing periods at the end of the cryogenic mission.

SRoll scheme[edit]

SRoll makes use of an extended destriper. Destriper method have been used previously to remove baseline drifts from detector time streams, while making co-added maps of the data, by taking advantage of the redundancy in the scanning strategy. \sroll\ is a generalized polarized destriper which, in addition, compares all the observations of the same sky pixel by the same detector with different polarization angles, as well as by different detectors within the same frequency band. This destriper thus fits differences between instrument parameters that minimize the difference between all polarized observations of the same sky pixel in the same frequency band. \sroll\ solves consistently for:

  • one offset for each pointing period,
  • an additional empirical transfer function to the correction already done in the TOI processing, covering the missing low frequency parts in both spatial and temporal domains,
  • a CMB calibration mismatch between detectors on the total kinetic dipole,
  • a bandpass mismatch for foregrounds response due to color corrections with respect to the CMB calibration, using spatial templates of each foreground,
  • the absolute calibration from the orbital dipole which does not project on the sky.

With all these differential measurements, the absolute value of some of the parameters is given by constraints on the average of all detectors in a frequency band imposing:

  • the sum of the offsets to be zero (no monopoles),
  • the average of the additional color corrections (for both dust and free-free emission) to be zero, thus keeping the same average as the one measured on the ground.

Products[edit]

Previous Releases: (2015) and (2013) Mapmaking and photometric calibration[edit]

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2015 Mapmaking and photometric calibration

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2013 Mapmaking and photometric calibration

References[edit]

  1. Jump up to: 1.01.11.21.31.41.5 Planck 2013 results. VI. High Frequency Instrument Data Processing, Planck Collaboration, 2014, A&A, 571, A6.
  2. Jump up to: 2.02.12.2 Planck 2013 results. VIII. HFI photometric calibration and Map-making, Planck Collaboration, 2014, A&A, 571, A8.
  3. Jump up to: 3.03.13.23.33.43.5 Planck 2015 results. VIII. High Frequency Instrument data processing: Calibration and maps, Planck Collaboration, 2016, A&A, 594, A8.
  4. Jump up Planck intermediate results. XLVI. Reduction of large-scale systematic effects in HFI polarization maps and estimation of the reionization optical depth, Planck Collaboration Int. XLVI A&A, 596, A107, (2016).
  5. Jump up Planck 2018 results. III. High Frequency Instrument data processing and frequency maps, Planck Collaboration, 2020, A&A, 641, A3.
  6. Jump up to: 6.06.1 Planck 2013 results. XIII. Galactic CO emission, Planck Collaboration, 2014, A&A, 571, A13.
  7. Jump up to: 7.07.17.2 Planck 2015 results. X. Diffuse component separation: Foreground maps, Planck Collaboration, 2016, A&A, 594, A10.
  8. Jump up Planck 2015 results. VII. High Frequency Instrument data processing: Time-ordered information and beam processing, Planck Collaboration, 2016, A&A, 594, A7.
  9. Jump up Five-Year Wilkinson Microwave Anisotropy Probe (WMAP) Observations: Data Processing, Sky Maps, and Basic Results, G. Hinshaw, J. L. Weiland, R. S. Hill, N. Odegard, D. Larson, C. L. Bennett, J. Dunkley, B. Gold, M. R. Greason, N. Jarosik, E. Komatsu, M. R. Nolta, L. Page, D. N. Spergel, E. Wollack, M. Halpern, A. Kogut, M. Limon, S. S. Meyer, G. S. Tucker, E. L. Wright, ApJS, 180, 225-245, (2009).
  10. Jump up Planck 2013 results. XV. CMB power spectra and likelihood, Planck Collaboration, 2014, A&A, 571, A15.
  11. Jump up Planck 2013 results. XXXI. Consistency of Planck data, Planck Collaboration, 2014, A&A, 571, A31.

(Planck) High Frequency Instrument

Data Processing Center

Cosmic Microwave background

(Hierarchical Equal Area isoLatitude Pixelation of a sphere, <ref name="Template:Gorski2005">HEALPix: A Framework for High-Resolution Discretization and Fast Analysis of Data Distributed on the Sphere, K. M. Górski, E. Hivon, A. J. Banday, B. D. Wandelt, F. K. Hansen, M. Reinecke, M. Bartelmann, ApJ, 622, 759-771, (2005).

analog to digital converter

Noise Equivalent Power

Full-Width-at-Half-Maximum

reduced IMO

Planck Sky Model