Rigorous radiometric calibration of airborne AeS-1 InSAR data

The processing of synthetic aperture radar images usually does not include topographic information, and therefore significant radiometric uncertainties remain, making the processed data not directly suitable for signature analysis, for classification purposes or to relate SAR data to geophysical parameters. An accurate SAR data calibration in areas with terrain variations can only be accomplished considering high resolution elevation data, precise position and attitude data of the antenna, and the appropriate SAR geometry. Using these information one is able to correct each pixel in terms of radiometry. The AeS-1 interferometric SAR system allows the generation of high resolution surface height information at X-band. A rigorous approach to radiometrically calibrate the amplitude data is presented in this paper. Surface heights and slope variations derived from the interferometric phase are exploited for this purpose, considering also precise antenna pointing variations and topography for the antenna gain correction. The presented method is demonstrated for a test site having different terrain morphologies