ATSR-2 - THE EVOLUTION IN ITS DESIGN FROM ERS-1 TO ERS-2

The Along-Track Scanning Radiometer, or ATSR, was developed for the ER S-1 mission as an Announcement of Opportunity package by the United Ki ngdom and France. It consists of a four-band Infrared Radiometer (IRR) to measure the Sea Surface Temperature (SST), and a Microwave Radiome ter (MWR) to measure the integrated (vapour and liquid) atmospheric wa ter content. The IRR was developed by Rutherford Appleton Laboratory ( RAL, UK) and the MWR by the Centre de Recherche en Physique de I'Envir onment Terrestre et Planetaire (CRPE, F). For the ATSR-2 on ERS-2, the IRR has been upgraded by adding three more bands in the visible part of the spectrum to provide data for vegetation studies (Fig 1). The MW R is identical to that used on ERS-1, but is provided by a different i ndustrial contractor, namely Schrack Aerospace of Austria.