Variations in radar backscatter across the great ice sheets

Radar backscatter over the great ice sheets is modulated by the near surface properties of polar firn. These properties (grain size, density, stratigraphy, wetness) change in time and from region to region. Information was compiled on the spatial variation in backscatter across selected parts of Antarctica and Greenland from ERS-1 SAR data. The SAR-derived σ° compared favorably with both in situ and the ERS-1 scatterometer data obtained from literature. These results will be used to refine processing schemes for the Radarsat Antarctic Mapping Project. A difference plot of the azimuthal anisotropy of SAR-derived σ° was created to determine the magnitude of azimuthal anisotropy on a pixel by pixel basis. Azimuthal variability for a region of the Antarctic Peninsula was found to vary from 0 to 14 dB