SNOW PARAMETER DETERMINATION BY MULTICHANNEL MICROWAVE RADIOMETRY

A long-term observational program on the microwave scatter and emission behavior of snow began in 1977 at a high-altitude Alpine test site. The brightness temperatures at 4.9, 10.5, 21, 36, and 94 GHz measured at different incidence and polarization angles during the first season are analyzed with the aid of correlation, factorial, and cluster algorithms. The structure mathematically found within the data is compared with classical parameters of the snow cover. Snow state changed from a high winter state to a late spring state during our measurements. At least three different snow qualities and two grades of moisture for the uppermost 10 cm of the snow layer can clearly be distinguished with a high degree of accuracy. The information content of our measurements does not substantially degrade by reducing our data to data as delivered by the NIMBUS-5 and as expected of the NIMBUS-G satellites. Recommendations for optimum frequencies for the remote sensing of snow are given. © 1979.