THE 0.4 ARC-SEC TANDEM-X INTERMEDIATE DEMWITH RESPECT TO THE SRTM AND ASTER GLOBAL DEMS

Recently a preliminary version of the new global DEM collected by the TanDEM-X mission became available to the scientific commu-nity: the TanDEM-X Intermediate DEM (IDEM) version. It is available over selected areas of the globe with a pixel spacing of 0.4, 1 and 3 arc-seconds. This paper presents the TanDEM-X IDEM with respect to global and local elevation data over Aegean Islands with mountainous terrain: the SRTM and ASTER global DEMs, and the national network of triangulation pillars (trig-points) and national archive Digital Terrain Model. Possible systematic 3D translations between global DEMs and local data are also determined and the relative gain in accuracy is assessed. TanDEM-X IDEM is shown to be dramatically enhanced with respect to the other global DEMs although a few jitters exist. 1