Sentinel 2: implementation of the means and methods for the CAL/VAL commissioning phase

Abstract

In partnership with the European Commission and in the frame of the Copernicus program, the European Space Agency (ESA) is developing the Sentinel-2 optical imaging mission devoted to the operational monitoring of land and coastal areas. The Sentinel-2 mission is based on a satellites constellation deployed in polar sun-synchronous orbit. Sentinel-2 will offer a unique combination of global coverage with a wide field of view (290km), a high revisit (5 days with two satellites), a high resolution (10m, 20m and 60m) and multi-spectral imagery (13 spectral bands in visible and shortwave infra-red domains). The first satellite is planned to be launched in late 2014. In this context, the Centre National d’Etudes Spatiales (CNES) supports ESA to insure the cal/val commissioning phase. This paper provides first, an overview of the Sentinel-2 system and the image products delivered by the ground processing. Then the paper will present the ground segment, presently under preparation at CNES, and the various devices that compose it : the GPP in charge of producing the level 1 files, the “radiometric unit” that processes sensitivity parameters, the “geometric unit” in charge of fitting the images on a reference map, MACCS that will produce Level 2A files (computing reflectances at the Bottom of Atmosphere) and the TEC-S2 that will coordinate all the previous software and drive a database in which will be gather the incoming Level 0 files and the processed Level 1 files.