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

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.