Global Ice Sheet Mapping Observatory: Airborne experiments

We describe tests of a radar-system concept envisioned to measure the spatial reflectivity and the 3-dimensional surface and basal topography of terrestrial ice sheets and to determine the physical properties of the glacier bed. We conducted experiments during May 2006 over northwestern Greenland using a 150 MHz radar operated from a Twin Otter aircraft. We conducted more extensive experiments in September 2007 over northern and central Greenland when we operated 150 and 450 MHz radars installed on the NASA P-3 aircraft. We performed a final set of Twin Otter supported 150 MHz experiments in July 2008 near Jacobshavn Glacier in western Greenland. Here we show 150 and 450 MHz interferograms of the ice sheet base. We use both radar interferometry and tomography to construct three-dimensional bottom topography.