Estimating a Volumetric Backscatter Coefficient from Measurements on the Greenland Ice Sheet

Abstract

Abstract — We obtained in-situ radar backscatter data at several sites on the Greenland Ice Sheet to better relate scattering signatures to flrn physical properties. Backscatter measurements were made using an ultra-wide band radar system (,5-18 GHz) for incidence angles between O and 50 degrees, with respect to the snow surface. For large angles of incidence (> 25°) the measured backscatter is dominated by volumetric scattering, as opposed to surface and specular backscatter occurring at near normal incidence. Using the data we present a method for estimating the volumetric backscatter coefficient as a function of depth in flrn. Results show trends consistent with both seasonal variations and long-term grain growth, which is primarily influenced by the accumulation rate I