Capability of multitemporal ERS-1 SAR data for wet-snow mapping

The backscattering behavior of the snow cover was investigated on the basis of nine European Remote Sensing-1 Synthetic Aperture Radar (ERS-1 SAR) images of a southeastern Québec study area in Canada (center latitude 47°30′ N, center longitude 69°45′W), which were acquired in the winters of 1992 and 1993. Comparative field measurements on physical properties of the snow cover were carried out in 25 test sites. Dry snow shows backscattering coefficients similar to those of snow-free surfaces, whereas backscattering is clearly reduced for wet snots. An algorithm was developed for wet-snow mapping by means of C-band SAR, based on multitemporal ERS-1 data. The SAR-derived snow imps could be successfully applied for runoff modeling during a full period of snow melt. The accuracy of the method for wet-snow mapping demonstrates the high operational potential of SAR. C-band ERS-1 SAR has been proved to be a suitable device for snow monitoring. It is of great interest for studies in hydrology. For our experimental conditions, the algorithm operates with a relative false detection ratio of 1.33% for the study area.