Map-making

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Introduction[edit]

Flux calibration[edit]

Noise properties[edit]

Zodi correction[edit]

Zodiacal Emission is removed from the 353, 545 and 857 GHz channels. It is described in the HFI DPC Paper, but a synopsis of the procedure is as follows:

  • During each survey, a large fraction of the sky has observations which all fall within a week of each other. That is, during a single survey, most pixels are observed during a short, well-defined period. The contribution from Zodiacal Emission to the total brightness seen, then, is well defined.
  • We use the the COBE model of the Zodiacal Light to make predictions for this Zodiacal emission for those pixels observed over a span of one week or less, and use GRASP models of the beams to predict the emission from the Galaxy given our sidelobes.
  • We fit the survey difference maps with these model templates to estimate the emissivity of each Zodi component and sidelobe at the Planck wavelengths.
  • We reconstruct each ring of the the full mission using the combination of the COBE geometric model with the emissivities determined above and the sidelobe models.
  • We remove the reconstruction above from each ring of data.
  • We then make maps as described in section elsewhere in this section.

Far Sidelobe Correction[edit]

CO Correction[edit]

Map validation[edit]

[LFI meaning]: absolute calibration refers to the 0th order calibration for each channel, 1 single number, while the relative calibration refers to the component of the calibration that varies pointing period by pointing period.

(Planck) High Frequency Instrument

Data Processing Center