Results from a Ground-Based Microwave Multi-Frequency Radiometer Campaign of Seasonal Snow in Finland

The brightness temperature of snow-covered terrain was monitored from January 2 through April 21, 1985. Ground- based radiometers operating at 37, 16.5 and 1 GHz (vertical and horizontal polarization) were used. The ground was partially covered with aluminum sheets, allowing measurement of both snow-covered ground (incidence angle 30 to 60 degrees) and snow only (10 degrees). Detailed ground truth data concerning snow, soil and weather were collected. In order to obtain layered dielectric and extinction information on snow in the test site under a variety of weather conditions, a total of 200 slabs of snow were taken from different depths and measured with free-space transmission systems operating at 12 GHz, 18 GHz (occasionally) and 35 GHz. This paper concentrates on the 37 and 16.5 GHz radiometer results for dry snow and also discusses the effects of snow wetness to the brightness temperature.