Medium-Resolution Imaging Spectrometer (MERIS) stray light design

MERIS is a passive optical instrument, that will fly on the first polar orbiting Earth observation mission ENVISAT. The development of this instrument is currently carried by an international team led by AEROSPATIALE. The instrument primary mission goal is to monitor bio-optical ocean parameters on a large scale. Secondary goals of MERIS include atmospheric investigation on cloud and aerosols parameters and on land surface processes. The instrument will acquire 15 spectral images, programmable in width and position with a spectral sampling interval of 1.25 nm within the visible spectral range of 390 nm to 1040 nm. MERIS images will have, a swath width of 1100 km and spatial resolution of 300 m. The high radiometrical (1 to 5%) and spectrometrical performances (1 nm) will be provided by an on board calibration system. This paper describes the straylight design of the instrument and associated performances in order to obtain the high level of radiometric resolution.