Influence of land-cover category on brightness temperature of snow

A helicopter-borne multifrequency radiometer (24, 34, 48 and 94 GHz vertical polarization) was used to investigate the behavior of the brightness temperature of snow in Sodankyla (latitude: 67.41 N, longitude: 26.58 E), Northern Finland. The measurements were carried out during dry snow, wet snow, and snow-free conditions. The angle of incidence was 45 degrees in all measurements. The measurements and the main results are presented. The analysis is focused on the effect of vegetation and land type on the brightness temperature of snow. The main topics of this paper are: a) the general behavior of the brightness temperature of snow for different land types, b) the effect of forest vegetation on the brightness temperature of snow, and c) the capability of the radiometer system to monitor snow extent in forests during the melting period.