The ACD Pedestals and Gains used in processing are based on ground calibrations and can be greatly improved.
ACD Pedestals
As seen in this report, The ACD pedestals values are pretty close to the ground data, with deviations of up to 20-30 pha counts. Correctly subtracting the pedestals will improve our handling of small signals in the ACD and reduce the self-veto.
The relevent file is at:
/afs/slac.stanford.edu/g/glast/ground/releases/calibrations/ACD/PROD/ACD_Ped/vanilla_flight_peds_080626.xml
ACD Gain (aka MIP calibration)
As seen in this report, The ACD MIP peak values are generally 20% higher in orbit that on the ground. In addition are dozen channels or so are badly miscalibrated in the ground data. Correctly applying the MIP calibrations will improve our calibration of signals in the ACD and reduce the self-veto and improve background rejection efficiency.
The relevent file is at:
/afs/slac.stanford.edu/g/glast/ground/releases/calibrations/ACD/PROD/ACD_ElecGain/vanilla_flight_gains_080630.xml