This Level is responsible of the whole 1D (i.e. on detectors timelines) and the subsequent 2D Sky Map building for each of HFI frequencies. This includes Astrometric and Photometric Calibration, Glitch Removal, Control of all possible Systematics, followed by sky map building using the information comming from various sky scans by various detectors at the same frequency, both for signal Intensity ("Thermal" ) and Polarisation. An added task is the creation, early during the mission ( 1 year after completion of the first survey) of an Early Release Compact Source Catalogue (ERCSC) in order to enable the astrophysical community to make some follow-up observation as soon as possible.

This task is under the responsibility of F. Bouchet (IAP, Paris, France).