Comparison of Measurements and Theory for Backscatter from Bare and Snow-covered Saline Ice

Abstract

C-band backscatter measurements were made on artificially grown sea ice at the U.S. Army Cold Regions Research and Engineering Laboratory (CRREL) during the winters of 1987-1988 and 1988-1989. These measurements were made on smooth, rough, and snow-covered saline ice. The measured 0° (0) of smooth saline ice (rms height < 0.05 cm) disagreed with small perturbation method (SPM) surface scattering predictions. Using physical parameters of the ice in a simple layer model, we show that this discrepancy can be explained by scattering from beneath the surface. A thin (7-cm) dry snow cover had a significant influence on backscatter from the smooth ice sheet. This influence was due to scattering from particles within the snow and can be predicted by a commonly used empirical layer model for snow. The results of backscatter measurements of a moderately rough saline ice sheet were found to agree with SPM predictions.