Propagation Effects and Polarimetric Methods in Synthetic Aperture Radar Imaging

Abstract

In this study, the influence of the atmosphere on the imaging capabilities of synthetic aperture radar (SAR) is investigated. One goal was to identify any potential effects capable of distorting SAR images. Investigations on the influence of phase errors and attenuation effects were carried out. Likewise a special experiment, called ATMOSAR (Atmospheric SAR Experiment) has been performed in order to determine possible distortions. A differential interferometric synthetic aperture (DinSAR) analysis was carried out which revealed that differences appearing in the differential interferograms are primarely either due to residual motion errors resulting from the limited baseline accuracy or based on soil moisture changes (temporal decorrelation) and possibly topographical changes between the two acquisitions. Furthermore, an algorithm is presented, which allows identification of artefacts in SAR images caused by heavy precipitation events. An additional aspect of this work was the introduction of the novel target decomposition techniques, namely the ”principal component analysis” and the ”Gersgorin disc theorem” and its applications.