A hyperspectral imager for the future ESA land surface processes Earth Explorer Mission

The Land Surface Processes and Interaction Mission is one of the candidates for the future Earth Explorer Missions, which are planned to be launched beyond the year 2003 after the ENVISAT and METOP programmes. The scientific requirements for such a mission can be met by PRISM, a hyperspectral imager studied by ESA which makes simultaneous measurements of reflectance and temperature of selected sites of the Earth. PRISM is designed to be flown in a polar sun-synchronous orbit, providing coregistered images in the Visible and Short-Wave InfraRed (0.45 - 2.35 mu m), with a spectral resolution of about 10 nm, and the thermal IR range from 3.5 to 12.3 mu m, divided into 4 spectral bands with a typical width of 1 mu m PRISM will make simultaneous observation of the same scene in all spectral bands with tight coregistration. The spatial sampling on ground is about 50 m over a swath of 50 km. Across-track pointing capability is available for convenient accessibility of the observation sites. The paper describes the main mission and instrument requirements with emphasis on the radiometric requirements. Results of the system feasibility studies will. be given. The most important results of the related technological developments will also be discussed.