Vol. 4, No. 1, 119-129, 2005

Abstract
The Swiss Federal Institute for Snow and Avalanche Research in Davos (SLF) publishes daily snow and avalanche information including snow depth maps on a spatial resolution of 1x1 km² for Switzerland. These maps are generated using a spatial interpolation technique based on snow station measurements. Although the station network has become denser over the past years, several regions do not contribute well to the network. The U.S. National Oceanic and Atmospheric Administration (NOAA) Advanced Very High Resolution Radiometer (AVHRR) sensor is used to improve the information on snow-covered ground. The fusion of point measurements with small-scale remote sensing data leads to an improved area-wide snow information. The presented merging technique based on virtual snow stations is applied for a case study on the Swiss Alps on 4 January 2005. The combination technique is a new approach and the resulting nation-wide snow depth maps show a significant improvement compared to the conventional interpolation with a more accurate snow – no snow borderline. The interpolation method seems to be sensitive to an accurate snow - no snow classification of the satellite data. The preliminary results are very promising and a near-real time application is already in operational use. Ongoing work is concentrating on the validation of the snow cover maps and improvements to the spatial interpolation method.

ISSN 1729-3782