Calibration and classification of SIR-C polarimetric and interferometric SAR data in areas with slope variations

The goal of this paper is to present the capabilities and the limitations of SIR-C SAR magnitude data (dual frequency, dual polarization) and dual frequency interferometric SAR data for land cover classification purposes in areas with slope variations. The work consists of three parts. In a first step SIR-C SAR magnitude HH-, HV-polarized data acquired during the SRL-2 mission (DT 110.00) over an area with terrain ranging from hilly to mountainous (around 1800 sq. km) in Central Switzerland is geometrically and radiometrically calibrated, considering scattering area variations and radiometric errors due to topographic effects on the antenna gain pattern. After this step the backscattering coefficient is classified using a supervised method taking a-priori information into account (thematic and topographic information). In a second step, repeat-pass SIR-C InSAR VV-polarized data (DT 142.12 and 158.12) acquired 24 hours later over the same site is interferometrically processed. In order to correct the interferometric phase for slope variations and therefore to improve the coherence estimation the InSAR data is terrain geocoded. Only after these calibration steps can the backscattering coefficient and coherence data be qualitatively and quantitatively analysed