Multi-Channel SAR Instrument Calibration Using the Spatial Correlation Properties of Homogeneous Scenes

Abstract

Synthetic Aperture Radar (SAR) instruments with multiple channels in azimuth and elevation are of great interest for near-future satellite missions. An on-board calibration of the channels can be performed by utilizing the raw SAR data. For a radar clutter signal the spatial correlation between the channels is employed. However, to calibrate the elevation channels of a SAR instrument with said method the SAR geometry, the transmitted signal properties, the patterns as well as multiple simultaneous echoes have to be taken into account. A model incorporating these considerations is presented in this paper. A comparison of the SAR measurements to the model allows a calibration of the SAR instrument.