sentinel-3A SLSTR – Early results The main objective of the Sentinel-3 SLSTR instrument is to maintain continuity with the ENVISAT (A)ATSR series of instruments within the European Copernicus programme. SLSTR will retrieve global coverage sea surface skin temperature (SSTskin) with zero bias and an uncertainty of ± 0.3 K (1σ) for a 5 x 5 degree latitude longitude area, having a temporal stability of 0.1 K/decade in support of Copernicus climate monitoring and operational Numerical Ocean/Weather Prediction (NOP/NWP) applications. In addition, SLSTR using a suite of visible and infrared radiance measurements, monitoring, ice surface temperature, cloud imagery, atmospheric aerosol, land, forestry and hydrology products in support of Copernicus serviceswill provide land surface temperature, active ﬁre. This poster presentation presents initial results from the Sentinel-3A SLSTR as of May 25th 2016. C. Donlon, D. Smith (RAL), B. Berruti, J. Nieke and J. Frerick. Contact: Craig.Donlon@esa.int and for dave.smith@stfc.ac.uk further information. èAbout sentinel-3 Sea and Land Surface Temperature Radiometer è A BIGGER PICTURE FOR COPERNICUS SLSTR Band L Centre [µm] ΔL [µm] SNR [-] / NeΔT [mK] Spatial Sampling Distance (SSD) [km] Function S1 0.555 0.02 20 0.5 Cloud screening, vegetation monitoring, aerosol S2 0.659 0.02 20 0.5 NDVI, vegetation monitoring, aerosol S3 0.865 0.02 20 0.5 NDVI, Cloud flagging, Pixel co- registration S4 1.375 0.015 20 0.5 Cirrus detection over land S5 1.61 0.06 20 0.5 Cloud clearing, Ice and snow, vegetation monitoring, S6 2.25 0.05 20 0.5 Vegetation State and Cloud Clearing S7 3.74 0.38 80 mK 1.0 SST, LST, Active Fire S8 10.95 0.9 50 mK 1.0 SST, LST, Active Fire S9 12 1.0 50 mK 1.0 SST, LST F1 3.74 0.38 < 1 K 1.0 Active Fire F2 10.95 0.9 < 0.5 K 1.0 Active Fire èSpectral channels èSLSTR Optical design ç The complete suite of AATSR and ATSR-2 spectral channels (0.55, 0.66, 0.85, 1.6, 3.7, 10.8 and 12 µm) is included in the SLSTR design in order to maintain continuity. Additional channels at 1.378 µm and 2.25 µm are included to enhance thin cirrus cloud detection. SLSTR has an additional capability to derive active ﬁre measurements using an extended dynamic range of the 3.7 µm channel and dedicated optimized detectors at 10.8 µm that are capable of detecting ﬁres at ~450 K without saturation. è SLSTR uses two independent scan chains each including a separate scan mirror (scanning at a constant velocity of 180 rpm), an off-axis paraboloid mirror, and a fold mirror to focus measured radiance into the instrument Detector Assembly (DA). An innovative recombination “ﬂip” mirror alternately relays each of the scanned optical beams into a common ﬁeld plane at the entrance of the DA where there is a cold bafﬂe. ç While more complex than the single scan system employed by the (A)ATSR instrument series, the SLSTR 3-mirror scan conﬁguration increases the instrument oblique view swath to ~750 km (centred at the SLSTR nadir point) and the nadir swath to~1400 km (offset in a westerly direction). The nadir swath is asymmetrical with respect to the nadir point to provide identical and contemporaneous coverage with OLCI ocean/land colour measurements. Visible and short-wave infrared detectors have a spatial resolution of 0.5 km on ground. Thermal infrared detectors have a spatial resolution of 1 km on ground. 05/04/2016 10:02 am. The first image from the Sentinel-3A SLSTR thermal-infrared channels at 1km spatial resolution reveals thermal signatures over a part of western Namibia and the South Atlantic Ocean. Cold water is seen along the Namibian coast upwelling from deeper waters. The Benguela current flows north along the west coast of South Africa driven by southeasterly winds, creating coastal upwelling. Many eddies and meanders are generated in this complex system and these small-scale features are captured beautifully. Over land, the distinct folds of desert dunes can be seen. In fact, further north, Gobabeb is the locati