MERIS - A new generation of ocean-colour sensor onboard Envisat

ESA has developed a multidisciplinary Earth-observation instrument that foc uses on biological ocean observations. This Medium Resolution Imaging Spect rometer (MERIS) will provide a remote-sensing capability for observing, int er alia, oceanic biology and marine water quality through observations of w ater colour. MERIS, which will be the first spaceborne wide-field imaging s pectrometer, is a nadir-looking sensor operated in a push-broom mode. The i nstrument measures the solar reflected radiation in fifteen spectral bands in the visible and near-infrared parts of the spectrum. Of particular inter est is the ability to programme the position and width of the spectral band s in flight. This allows a large set of applications, making the instrument concept also attractive for future Earth Watch missions. ESA will produce a set of validated data products, such as chlorophyll concentration, water vapour and global vegetation index, which will be available at two spatial resolutions (300 m and 1200 m).