Determination of Glacier Velocities on King George Island (Antarctica) by DInSAR

The Antarctic Peninsula is a region highly sensitive to climate change. For ice dynamic modelling and climatic impact studies several parameters have to be known. Radar interferometry is a feasible method in such remote areas to derive velocity fields. For King George Island, the available ERS-1/2 tandem pairs with reasonable baselines have been processed. Due to temporal decorrelation only 2 out of 19 pairs showed almost everywhere high coherence and an additional 6 have partial moderate coherence. A SAR DEM was constructed by double differencing interferometry. Ascending and descending scenes were combined to derive a velocity field for the main part of the Island. External elevation data were additionally incorporated in the processing. Glacier velocities range between 0 m and about 120 m per year. Validation with DGPS measurements from several field campaigns shows good agreement with the interferometric derived velocities. Inaccuracies exist for the edges of the ice cap as here decorrelation effects hampered the generation of an InSAR DEM and no external data were available.