The IASI processing system generates calibrated atmospheric spectra from raw interferograms. These spectra are ready for assimilation by users and are processed on-board the instrument and by the associated ground segment.
On-board processing reduces the data rate from 45 Megabits per second to 1.5 Megabits per second. The algorithms used to process the raw interferograms basically correct non-linearities in the detection process, calculate the inverse optical Fourier transform and perform radiometric calibration of the spectra obtained. These spectra are downlinked from the satellite to the ground segment and form level 0 data.