Status of the Sea & Land Surface Temperature Radiometer (SLSTR) for the Sentinel 3 GMES Mission

The Sea & Land Surface Temperature Radiometer (SLSTR) is a high accuracy infrared radiometer selected as optical payload for the Sentinel 3 component of the GMES mission, to provide climatological data continuity respect to the previous ERS and ESA Envisat missions, that embarked respectively the ATSR, ATSR-2 and AATSR payloads. The instrument design follows the dual view concept of the ATSR series with some notable improvements. An increased swath width in both nadir and oblique views (1400 and 740 km) provides measurements at global coverage of Sea and Land Surface Temperature (SST/LST) with daily revisit times, which is useful for climate and meteorology (1 Km spatial resolution). Improved day-time cloud screening and other atmospheric products will be possible from the increased spatial resolution (0.5 Km) of the VIS and SWIR channels and additional SWIR channels at 1.375μm and 2.25μm. Two additional channels using dedicated detector and electronics elements are also included for high temperature events monitoring (1 km spatial resolution). The two Earth viewing swaths are generated using two telescopes and scan mirrors that are optically combined by means of a switching mirror at the entrance of a common Focal Plane Assembly. The eleven spectral channels (3 VIS, 3 SWIR, 2 MWIR, 3 TIR) are split within the FPA using a series of dichroics. The SWIR, MWIR and TIR optics/detectors are cooled down to 80 K with an active cryocooler, while the VIS detectors work at a stabilised uncooled temperature. The paper highlights the technical and programmatic status of the project, which is now in phase C.