PREPARING THE USE OF PLEIADES IMAGES FOR MAPPING PURPOSES: PRELIMINARY ASSESSMENTS AT IGN-FRANCE

The Pleiades system, of which the first platform of the constellation shall be ready for launch in early 2009, is the new generation of high resolution optical sensor satellites developed by CNES, the French space agency. With its ability to provide photogrammetrists with instantaneous colour image stereo-pairs of 20km swath and 70cm resolution acquired with B/H ratios ranging from 0.15 to 2, the very agile and precisely pointing Pleiades platforms should open in many countries a new era for the updating of high scale maps, by probably avoiding heavy aerial survey campaigns in many cases. In the framework of a cooperation agreement between CNES and IGN-France (IGN-F), designed to prepare an operational use of these images, several experimentations and simulations are being carried out, in order to verify the ability of the system to fulfill the technical and operational requirements of the map-making processes, in comparison with those presently based on digital aerial photography. Among others, present studies particularly focus on: the geometric and radiometric quality assessment of the planned system products (sensor level, orthoimages and mosaics). the capacity assessment of the Pleiades constellation to meet the IGN-F cartographic mission needs in terms of image volume for the coverage of the national territory, whether in monoscopic or stereoscopic mode. the potential of stereo- and three-fold stereoscopic image simulations for the extraction of buildings in 3D, afte