Potential of Ers-1 Sar Data for Snow Cover Monitoring

The aim of this study is to develop a methodology to map the snow cover parameters (extent, state, liquid water content, snow water equivalent) from an orbiting SAR sensor (ERS-1 and eventually RADARSAT) and to use the resulting information as input to an hydrological simulation model. During the winter of 1992, ERS-1 scenes were ac uired over an agricultural region located to the EAST of Qut%ec City, in Eastern Canada. Snow cover and soil state were characterized by ground measurements over a number of sites in order to interpret quantitatively the SAR data. The pro osed methodology is based on the results of a previous study &ne at INRS-Eau. Those results suggest that a model based on the thermal properties of the snow cover could be developed to estimate the Snow Water Equivalent (SWE) with SAR data using a minimum of ground data. The preliminary analysis of the ground data indicates that a relationship between the surface temperature of the soil and the thermal resistance of the snow cover, similar to that found before, can be obtained. However, it is expected that a specific relationship could be obtained between the signal ratio and the thermal resistance of the snowpack for each soil type. Preliminary results of the SAR data analysis will be presented at the Symposium.