DEM Generation over Ice Fields in Nunavut with Along-track SPOT5 HRS Stereo Data

International audienceA digital elevation model (DEM) was generated using a SPOT5 HRS stereo pair acquired over a challenging ice field and fjord study site in Nunavut (80% of the area was ice covered and almost 50% of the area had 40 degrees slopes). The DEM was thus evaluated by comparison with a topographic 1959 DEM and ICESat data, over and outside the ice fields and as a function of slope. The DEM generation did not need any reference cartographic data for collecting ground control points. The method could be applied to ice-covered areas with a 15 m accuracy (1 sigma) over less than 5 degrees slopes or a 22 m accuracy (1 sigma) over less than 40 degrees slopes. In addition, a systematic elevation lowering of 8-10 m computed between 1959 DEM and recent elevation data (HRS and ICESat) could be due to ice field wastage over the last 50 year