Statistical methodology for monitoring radiometric performance of RADARSAT-1

An important objective of RADARSAT-1 is to provide users with geometrically and radiometrically calibrated products. This has been achieved largely through continuous long term monitoring of both point target measures at Canadian transponder sites, and the elevation beam patterns using the Amazon rainforest. This paper describes a statistical method useful for monitoring the radiometric performance of calibrated single beams during the life of the mission. The method is useful for early detection of radiometric problems associated with changes in the beam pattern shape or pointing; this is important for initiating the process of re-calibration of the beam pattern used by the processor.