Precipitation Induced Signatures in SAR Images

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 are present. This holds especially for the case of convective rain events imaged at X–band frequencies and beyond. 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, a first attempt is made to extrapolate the effects observed in X-band SAR images to images acquired at higher nominal frequency bands.