Map-making

Zodiacal Emission is removed from the 353, 545 and 857 GHz channels. It is described in ?????, 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.
• 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 ?????