Mapping snow cover extent using optical and SAR data

Abstract

Snow cover plays an important role both globally and regionally as it is fundamental for local water availability, river run-off, and groundwater recharge. Hence, the exact knowledge of extent and dynamic of the snow coverage is essential. This study combines synergetic optical and SAR data with the main object to map the snow cover extent. As the Sentinel-Mission provides a wide swath width and a high revisit time (2-3 days at mid-latitudes with same acquisition geometry), the Sentinel-1 Interferometric Wide Swath Mode (IW) SAR data and Sentinel-2 multi-spectral data are used. Additionally, the TanDEM-X DEM is applied for the exact determination of the snow line as well as for snow classification. The mapping of the snow cover extent is applied on the three test sites Devon Island in Canada, Nordenskiöld, Svalbard, and French Alps, France which are characterized by different topography and land cover. The classification achieved an overall accuracy of 85% for Devon Island, 60% for Nordenskiöld and 88 % for the French Alps.