Multi-source snow cover monitoring in the Swiss Alps

Methods for the application of ERS-1 SAR and L-5 TM imagery to monitor and map the snow cover in high mountain areas are presented. Snow monitoring using SAR data considering the multitemporal optimal resolution approach MORA results in a sequence of wet snow cover maps. The climbing of the snow-line could clearly be detected. Furthermore snow cover maps based on L-5 TM imagery are discussed. Considering spectral reflectances of snow a simple snow cover maps were derived. Analyzing advantages and disadvantages of the use of SAR or EO sensors, finally, a data fusion model was used to evaluate the potential of data fusion techniques for the retrieval of geoecological parameters, e.g. snow. Including the SAR γ-values in a RGB-YUV-RGB-model results show more textural information in snow covered areas while edge information originates from the TM imagery. The information content of the calculated image is increased. The potentials and limitations of the approaches are discussed