The goal of AATSR calibration and validation activities was to verify the accuracy and quality of data the instrument acquired.
Instrument and instrument data calibration activities involve pre- and post-launch measurements that are used to characterise the instruments fully, and subsequently configure the ground segment processors to provide calibrated products (Level 1 products). Subsequent validation activities involve the validation of geophysical products (Level 2 products) against independent geophysical measurements (i.e. in-situ measurements). Overall, the latter is used to derive the accuracy and quality of the instrument data.