Abstract
The microwave backscattering coefficient of ground covered with dry snow was observed at incidence angles of 25°, 35° and 45° using a C-band microwave scatterometer in winter in Sapporo, and relationships between the observations and snow water equivalent were examined. As a result, although the observations of each incidence angle did not show a correlation with the snow water equivalent, the differences between the observations at 25° and at 45° had a significant correlation with the snow water equivalent. This result shows possibility of estimating the snow water equivalent of dry snow pack using C-band multi-incident angular data with a Synthetic Aperture Radar (SAR) mounted on a satellite. From analysis using a backscattering model, it was guessed that an immediate factor in the increase of differences between observations at 25° and at 45° with the increase of the snow water equivalent was the change of the roughness condition of the soil surface (discontinuous plane of the dielectric constant) under dry snow pack. It was thought that this change of the roughness condition occurred along with snowmelt at the base of a snow pack.
