CONSIDERATION OF ANTENNA GAIN AND PHASE PATTERNS FOR CALIBRATION OF POLARIMETRIC SAR DATA

A general polarimetric model for orbital and earth, SAR systems, which explicitly includes key radar architecture elements and is not depend ent on the reciprocity assumption has been developed. The model includ es systems whose receiving configuration is independent of the transmi tted polarization (one configuration), as well as systems with two dis tinct receiving configurations according to the commanded transmitted polarization (H or V). The distortion matrices in this model separatel y consider parameters that are independent of target illumination angl e and those with illumination angle dependence, thus allowing calibrat ion approaches which are valid for targets at different illumination a ngles, provided that the complex antenna elevation gains are known. Th e calibration methods presented here make use of the model linearity t o provide tests for the radar model accuracy and for SAR data quality. X-band polarimetric SAR data acquired by CCRS in 1989, is used to val idate the theory and to illustrate the calibration approach. Extension of the model and calibration method to other radar systems is discuss ed.