Qualification of SRTM DEM. A first approach toward an application dependant qualification framework

The now well-known SRTM (Shuttle Radar Topography Mission) mission, launched in February, 2000 for 11 days, used C-band and X-band interferometric SAR to acquire data all over the Earth surface. These data allowed to generate the world´s largest DEM. The aim of our study is to assess the quality of the SRTM DEM derived from the X-SAR system, compared with the quality of a reference DEM and of DEM from other sources. An important aspect of the study is to be able to conclude on the real relevancy of the SRTM product compared to the already existing products, for instance is it to be considered as a new global topographic reference or should it be only limited to some applications. The chosen test site is the Grand Morin, watershed of the Seine river nearby Paris, France, that exhibits a wide thematic diversity. Beyond the qualification of SRTM products, we tried to develop a systematic framework for the analysis of quality, which constitutes a challenging issue nowadays.