Investigation of passive microwave signatures over snow-covered forest areas

Airborne passive microwave signatures collected in Northern Finland during EMAC-95 is analysed with the emphasis on forested areas and dry snow conditions. The microwave signatures covers the 6.8-18.7 GHz frequency range and are acquired at vertical and horizontal polarisation. The analysis is carried out with respect to the forest stem volume data and comprises three different snow depth situations. Emissivities indicate an exponential increase with stem volume, with a subsequent saturation at higher stem volumes. At 10.65 GHz the saturation level was found to be linearly related to snow water equivalent.