There are four distinct processing chains that correspond to Sentinel-3’s three main instruments, namely the Sea and Land Surface Temperature Radiometer (SLSTR), the Ocean and Land Colour Instrument (OLCI), the Synthetic Aperture Radar Altimeter (SRAL) and a combination of SLSTR/OLCI data that generate ocean colour and land reflectance, land and sea temperature, ocean and land topography core products and vegetation core products.