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UP: Fachverband Umweltphysik

UP 17: Satellitengestützte Messmethoden

UP 17.5: Vortrag

Mittwoch, 28. März 2007, 14:45–15:00, H48

Validation of Land Surface Temperatures (LSTs) derived from the MSG satellite with the Evora, Portugal ground-truth measurements — •Ewa Kabsch — Forschungszentrum Karlsruhe, IMK, Postfach 3640, 76021 Karlsruhe

Land Surface Temperature (LST) is an operational product generated from the Meteosat Second Generation (MSG) satellite data. The LST is the temperature that corresponds to the radiance emitted by the surface and it is calculated with an algorithm that performs correction for atmospheric effects based on differential absorption in adjacent infra-red MSG/SEVIRI bands (10.8 and 12.0 mikrom). The algorithm requires the emissivity as an input data. The LST product is validated with a ground-truth station. The main instrument at the validation station close to Evora in Portugal is a self-calibrating rotating radiometer with two black-bodies. Additionally, a second radiometer with a larger field of view is provided. The influence of emissivity is considered by the means of the radiometric sky temperature measurements. Due to the pixel size of MSG (~5x5 km2) the up-scaling is one of the most crucial matters by the validation. It is carried out in terms of the site characterisation. Several field investigations, as well as vegetation analysis with high resolution satellite images, showed that the structure of the site requires radiance measurements of tree crowns and ground. The station started operation in April 2005. However, due to overcast only some ground-based datasets are suitable for the comparison with the satellite product. This data and the validation results will be presented on the conference.