Title :
Passive microwave measurements of snow-covered forest areas in EMAC´95
Author :
Kruopis, Nerijus ; Praks, Jaan ; Arslan, Ali Nadir ; Alasalmi, Hanna M. ; Koskinen, Jarkko T. ; Hallikainen, Martti T.
Author_Institution :
Kaunas Univ. of Technol., Lithuania
fDate :
11/1/1999 12:00:00 AM
Abstract :
Airborne passive microwave signatures collected in Northern Finland during EMAC-95 are analyzed with the emphasis on forested areas and dry snow conditions. The microwave signatures cover the 6.8-18.7-GHz frequency range and were acquired at both vertical and horizontal polarizations. The analysis is carried out with respect to the forest-stem volume data and comprises three different snow-depth situations. Emissivities approach saturation limit with the increasing stem volume. At 10.65 GHz, the saturation level was found to be linearly related to the snow-water equivalent. On the basis of passive-microwave measurements, an empirical forest transmissivity model is developed. The model is valid at vertical polarization 50° incidence angle, and it accounts for microwave frequency and forest-stem volume effects in the range of 6.8-94 GHz and 0-150 m3/ha, respectively
Keywords :
forestry; hydrological techniques; radiometry; remote sensing; snow; terrain mapping; vegetation mapping; 6.8 to 94 GHz; EMAC´95; EMAC-95; Finland; SHF; biomass; dry snow conditions; forest; forest-stem volume; geophysical measurement technique; hydrology; incidence angle; microwave radiometry; passive microwave method; passive microwave signature; polarimetry; polarization; remote sensing; saturation limit; snow cover; snow-covered forest; snow-depth; snow-water equivalent; snowcover; snowpack; transmissivity model; vegetation mapping; Area measurement; Microwave measurements; Microwave radiometry; Ocean temperature; Polarization; Remote sensing; Sea measurements; Snow; Temperature sensors; Testing;
Journal_Title :
Geoscience and Remote Sensing, IEEE Transactions on
