Estimation of glacier ice extinction using long-wavelength airborne Pol-InSAR

Abstract

In recent years there has been increased interest in using synthetic aperture radar (SAR) to study and monitor glaciers and ice sheets for glaciological and climate change research. This paper describes the estimation of ice extinctions through modeling of Pol-InSAR (polarimetric interferometric SAR) coherences as a combination of a surface contribution (from the snow-firn interface and wind-induced sastrugi features) and a volume response. Ground-to-volume scattering ratios derived from a novel polarimetric decomposition are used in conjunction with Pol-InSAR coherence magnitudes to invert the extinction of the ice layer. The inversion is performed for experimental airborne Pol-InSAR data at L- and P-band acquired by DLR's E-SAR system over the Austfonna ice cap in Svalbard, Norway as part of the 2007 ICESAR campaign. Extinction-dependencies on frequency and glacier facie are investigated, and validation is performed comparing ground penetrating radar data to SAR backscatter and extinction values.