Monitoring the Receiver Gain Droop of ASAR

Inhalt:
Before launch it was known that the gain of ASAR’s receive window was not linear, that it ‘drooped’ over time. This was characterized on ground and is corrected for in the ASAR processor. However, despite the fact that the correction appears to work, this effect has never been measured in orbit. This paper describes an experiment to measure and characterize the receiver gain droop using a digital, coded calibration transponder.