Characterization of glacier facies using SAR polarimetry at long wavelengths

Abstract

At dry conditions, synthetic aperture radar (SAR) sensors are sensitive to both surface and sub-surface features of glaciers and ice sheets. In particular, polarimetric SARs (PolSAR) are sensitive to different scattering mechanisms as well as to geometrical and dielectric properties of the illuminated objects. Hence, they can potentially deliver information about several glaciological parameters. In this thesis, a novel three-component model is proposed to interpret PolSAR measurements of glaciers as the sum of volume and surface scattering components along with a newly-developed anisotropic propagation component. The latter is able to relate polarimetric phase differences to structural properties of firn with the potential to estimate its thickness, density and degree of anisotropy, helpful to improve glacier facies classification and surface mass balance estimation. The proposed model is tested with L- and P-band airborne data acquired by the E-SAR sensor of the German Aerospace Center (DLR) over the Austfonna ice cap, Svalbard. Results are validated by comparison with GPR and stratigraphic measurements.