The data as acquired by an instrument are not of any use for scientists. Scientists need these data to be transformed into physical variables. The process between the data as acquired by the instrument and the data as used by the scientist requires the development of algorithms based on physics and engineering, which also includes the instrumental corrections (see Instrumental calibration section).

In particular, isardSAT’s main expertise is in the first levels of instrument processing, from the instruments source packets (Level 0 / Level 1 processing) to retracking algorithms for Level 2 processing.