Sentinel-3B

Sentinel-3B is the second flight unit of the Copernicus Sentinel-3 programme, jointly operated by ESA and EUMETSAT. It launched on 2018-04-25 into a sun-synchronous orbit at 814.5 km altitude, 98.65 degree inclination, with a 10:00 descending node and a 27-day repeat cycle. When paired with Sentinel-3A the combined revisit is approximately 0.9 days globally. The satellite carries four main instruments: the Ocean and Land Colour Instrument (OLCI) for ocean colour and terrestrial vegetation monitoring; the Sea and Land Surface Temperature Radiometer (SLSTR) for sea and land surface temperature measurements; the SAR Radar Altimeter (SRAL) for ocean topography, sea ice and inland water level; and the Microwave Radiometer (MWR) providing wet-tropospheric path delay correction for the altimeter. Precise orbit determination is supported by DORIS, a GPS receiver, and a laser retroreflector. The mission delivers global measurements for ocean colour, sea surface temperature, sea level, sea ice, coastal water quality, and inland water extent. ^[1][2][3]