Difference between revisions of "Map-making"
| Line 11: | Line 11: | ||
Zodiacal Emission is removed from the 353, 545 and 857 GHz channels. It is described in <span style="color:red">the HFI DPC Paper</span>, but a synopsis of the procedure is as follows: | Zodiacal Emission is removed from the 353, 545 and 857 GHz channels. It is described in <span style="color:red">the HFI DPC Paper</span>, 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. | * 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 emission. | + | * We use the the COBE model of the Zodiacal Light to make predictions for this emission for those pixels observed over a span of one week or less. |
* We fit the survey difference maps with these model templates to estimate the emissivity of each component at the Planck wavelengths. | * We fit the survey difference maps with these model templates to estimate the emissivity of each component at the Planck wavelengths. | ||
* We reconstruct the full mission using the combination of the COBE geometric model with the emissivities determined above. | * We reconstruct the full mission using the combination of the COBE geometric model with the emissivities determined above. | ||
Revision as of 12:02, 18 October 2012
Contents
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 emission for those pixels observed over a span of one week or less.
- We fit the survey difference maps with these model templates to estimate the emissivity of each component at the Planck wavelengths.
- We reconstruct the full mission using the combination of the COBE geometric model with the emissivities determined above.
- We remove the reconstruction above from each ring of data.
- We then make maps as described in 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
