Reprocessing of TerraSAR-X Divided-Antenna Mode Data for Current Retrievals in Coastal Areas and Rivers

Most TerraSAR-X divided-antenna mode images exhibit noticeable ghost signatures of bright scatterers. These correspond to azimuth ambiguities in the SAR processing, which are particularly strong for divided-antenna mode data because the processing is done without azimuth bandwidth restrictions. When trying to retrieve surface currents from such data by along-track interferometry, the ghost signatures can produce strong artifacts, particularly for scenes with large contrasts between land and water. We propose a new reprocessing technique that uses adaptive multilooking to minimize the ghost signatures while maximizing the utilization of uncontaminated original information content to obtain an improved interferogram at a reduced resolution.