3D imaging of ice sheets

We developed and deployed, in July 2005, a wideband 8-channel synthetic aperture radar (SAR) at Summit Camp, Greenland (72.5783° N and 38.4596° W). The radar was designed to map internal layers, measure topography, and generate backscatter maps - all in a single pass. Information on ice thickness, bed topography and basal conditions is essential to the refinement of glaciological models of ice sheets, which are used to predict ice-sheet behavior (especially mass balance) and to select deep ice-core sites. This work focuses on the use of fine-resolution 3D imaging algorithms for combining all 8-channels to form cross-track image slices through the ice. As compared with traditional 2D depth sounding, these 3D images allow for the characterization of bed topography with very fine resolution. They also allow for the generation of strip-map SAR images with absolute geocoding without ground control points (these are unavailable at the bottom of the ice), and the ability to analyze the ice-sheet volume in 3D. Topography, backscattering, and 3D ice volume results are illustrated here.