Sentinel :ESA is developing a series of next-generation Earth observation missions, on behalf of the joint ESA/European Commission initiative GMES (Global Monitoring for Environment and Security).
Sentinel/OLCI-A :OLCI is an optical instrument used to provide data continuity for ENVISAT's MERIS. OLCI is a push-broom imaging spectrometer that measures solar radiation reflected by the Earth, at a ground spatial resolution of 300 m, in 21 spectral bands.