SENTINEL-2: geometric calibration during commissioning phase

Sentinel-2 is a multispectral, high-resolution, optical imaging mission, developed by the European Space Agency (ESA) in the frame of the Copernicus program of the European Commission. In cooperation with ESA, the Centre National d’Etudes Spatiales (CNES) is responsible for the image quality of the project, and will ensure the CAL/VAL commissioning phase. Sentinel-2 mission is devoted the operational monitoring of land and coastal areas, and will provide a continuity of SPOT- and Landsat-type data. Sentinel-2 will also deliver information for emergency services. Launched in 2015 and 2016, there will be a constellation of 2 satellites on a polar sun-synchronous orbit, imaging systematically terrestrial surfaces with a revisit time of 5 days, in 13 spectral bands in visible and shortwave infra-red. Therefore, multi-temporal series of images, taken under the same viewing conditions, will be available. This paper first briefly presents Sentinel-2 system, the design, the level-1 products, and the main geometric image quality requirements: geolocation with and without ground control points, multi-temporal and multi-spectral registration. Then, it presents the methods foreseen during commissioning: the viewing frames orientation, the focal plane mapping, the global reference image generation. Finally, it presents the Sentinel-2 image simulation tool, used to provide data for the validation of these developments.