SENTINEL-3 builds directly on the proven heritage of ERS-1, ERS-2 and ENVISAT. Its innovative instrument package includes:
A Sea and Land Surface Temperature Radiometer (SLSTR), based on ENVISAT's Advanced Along Track Scanning Radiometer (AATSR), to determine global sea surface temperatures to an accuracy of better than 0.3 K. The SLSTR improves the along track scanning dual-view technique of AATSR and provides advanced atmospheric correction. SLSTR measures in nine spectral channels and two additional bands. A 1.3 micron band aimed at cirrus detection and a 2 micron band aimed at vegetation, mineral and atmospheric corrections for very turbid waters. An SLSTR with spatial resolution in the visible and shortwave infra-red channels of 500 m and 1 km in the thermal infra-red channels.
An Ocean and Land Colour Instrument (OLCI), based on ENVISAT's Medium Resolution Imaging Spectrometer (MERIS). With 21 bands, compared to 15 bands on MERIS, a design optimised to minimise sun-glint and a resolution of 300 m over all surfaces, OLCI marks a new generation of measurements over the ocean and land. The swath of OLCI and nadir SLSTR fully overlap.
A dual-frequency (Ku and C-band) advanced Synthetic Aperture Radar Altimeter (SRAL), derived from ENVISAT RA-2, CRYOSAT SIRAL and JASON-2/POSEIDON-3, provides measurements at a resolution of approximately 300 m in SAR mode along track. SRAL is supported by a MicroWave Radiometer (MWR), derived from ENVISAT MWR for atmospheric correction and a Precise Orbit Determination (POD) package, including a GPS receiver (GNSS), a DORIS instrument and a Laser Retro-Reflector (LRR).
The combined topography package provides exact measurements of sea surface height, essential for ocean forecasting systems and climate monitoring. SRAL also provides accurate topography measurements over sea-ice, ice sheets, rivers and lakes.