SAR capabilities for alpine hydrology

Applications of SAR data for monitoring snow extent and soil moisture in alpine basins are investigated. The studies are based on C-band data from ERS SAR and Radarsat SAR from 1996 to 1998 and on polarimetric SIR-C/X-SAR data from April and October 1994. An algorithm for mapping wet snow is described which applies change detection technique to repeat pass SAR images. Effects of different look angles are studied using ERS SAR data (look angle 19/spl deg/) and Radarsat SAR Beam Mode S7 (look angle 40/spl deg/) data. In a case study the temporal change of the snow extent during the melting season 1998 is derived for a drainage basin in the Alps. Time series of C-band backscatter of alpine surface classes are studied to investigate the capabilities for monitoring soil moisture changes.