RADARSAT elevation antenna pattern determination

The operations plan for RADARSAT is based on implicit calibration of the imagery products from this sensor system. The determination of the antenna gain patterns in elevation for RADARSAT is a critical step in the radiometric calibration of this imagery. The shapes of the antenna patterns in elevation were derived from imagery collected over the South American rain forests of Brazil and Colombia with a consistency on the order of ±0.2 dB. The absolute levels of the patterns have been determined by superposing the shapes on results from a set of precision radar ground targets known as the RADARSAT Precision Transponders. As pattern revisions are determined, they are included operationally in the determination of the corrections that are required in the Canadian Data Processing Facility to create radiometrically calibrated image products