The calibration of AATSR data is led by the Rutherford Appleton Laboratory, who also maintain an AATSR webpage. The latest results are:
Please note that the above are type B estimates of the uncertainty due to systematic effects and not the random noise estimates.
Depending on the products you have, specific corrections may need to be applied to the VIS-SWIR channels in L1B products. Further information can be found here.
Note: these corrections have already been incorporated in the third reprocessing; no further action is required if you have only data from the third reprocessing.
AATSR 12 micron channel