Imaging of Snow/Ice Subsurface Features from Airborne Sar At UHF, L And X Band. The Onera Sar Campaign in South Greenland

An acquisition campaign of the ONERA airborne synthetic aperture radar system RAMSES have been set up on the Greenland ice-shelf to assess the detectability of buried objects and subsurface feature through dry snow/ice cover. Three band were investigated UHF band, L band and X band, forecasting a better penetration at lower band, but an higher radar cross section for a given object/feature at higher band, thus a trade off for the optimal frequency band to use that was not clear prior to experiment.Three sites were imaged, one in the accumulation zone North of the polar circle (East of Kangerlussuaq airport), one in the accumulation zone in a warmer southern area (East of Narsassuaq airport) and one in the intermediate zone between accumulation and ablation zones (plus a calibration zone and a front glacier close to Kangerlussuaq).Processing of the data revealed that both UHF and X band are indeed providing complementing results (deeper bigger feature versus shallow smaller features), but intermediate L band combining both drawbacks of higher attenuation and lower features RCS did not seem to yield any further information.