DEM corrected ERS-1 SAR data for snow monitoring

This paper presents the results from a study on the use of ERS-1 Synthetic Aperture Radar (SAR) data for snow parameter extraction in mountainous areas. Eight ERS-1 SAR data set and data from four field measurements from the Kvikne area in south Norway have been available. The data have been acquired during the snow melt period from April until June 1992. The SAR data have been calibrated and geocoded using Digital Elevation Model (DEM) data, and analysed in terms of evaluating the relationship between the backscattering coefficient sigma(o), and snow conditions. A decrease in sigma(o) of similar to 3 dB between dry and wet snow has been observed, which indicates that ERS-1 SAR data can be used for monitoring the extent of wet snow cover. Significant differences between sigma(o) as a function of local incidence angle for ascending and descending passes have been observed. These differences are likely to be explained by differences in snow properties. For the dry snow cover we have an indication of the volume scattering effects.