Geometric and radiometric terrain correction of ERS SAR data for applications in hydrologic modelling

SAR data has the potential to provide information about land surfaces and is therefore a candidate for hydrologic studies. A major problem in SAR application is the estimation of the backscatter coefficient. The backscatter coefficient is affected by the imaging geometry and the shape of the terrain. To employ radar data for quantitative evaluation it is necessary to calibrate and eliminate the impact of the terrain in the backscatter coefficient. In this paper a method to apply an exact terrain correction of the backscatter coefficient for ERS SAR data is described. The improvements in the derivation of soil moisture and biomass of meadows by using this terrain correction is shown.