Refining Sentinel-1 radiometric and pointing calibration by on-board temperature compensation emulation

Abstract:
The paper summarizes the on-board temperature compensation strategy implemented in the Sentinel-1 instrument and discusses its potential impact on S1 imagery. The temperature compensation is designed to cope with gain and phase drifts of the antenna elements induced by the temperature increase during long acquisitions. The strategy ensures very good long-term stability of the instrument, but it can introduce small radiometric artifacts and azimuth pointing variations in some acquisitions. In the paper, we present a procedure to predict such variations in order to compensate for them and further improve the S-1 calibration.