Propagation Effects in Satellite mounted Radar Remote Sensing

Abstract

Abstract—Active microwave SAR imaging of the Earth’s surface is commonly considered to be of all weather capability. However, as the operating frequencies of SAR-systems are increasing, visible image distortions due to heavy precipitation in SAR-images may become present. This holds especially for the case of convective rain events imaged at X–band frequencies and beyond. These rain-cell signatures are thoroughly investigated, and the physical background of the related propagation effects is provided. A review of rain-cell signatures from former missions like SIR-C/X-SAR and the Shuttle Radar Topography Mission are provided. Furthermore, the German spaceborne satellite TerraSAR-X delivered several measurements, which facilitate to study precipitation effects in SAR-images. Based on this SAR-images and simultaneously acquired weather radar measurements, a quantitative estimation of precipitation effects in SAR-images is presented. In a further step, an attempt is made to extrapolate the effects observed in X-band SAR images to images acquired at higher nominal frequency bands such as Ka-band.