Operational determination of satellite derived sea surface temperature and wind speed from NOAA AVHRR and ERS SAR images

Abstract

The intention of DLR's remote sensing activities is to provide the user community with geophysical information both on land and ocean surfaces in near real time with highest possible reliability on the thermatic quality. Towards this end, the German Remote Sensing Data Centre (DFD) as part of the Germany's aerospace research establishment (DLR) operates a High Resolution Picture Transmission (HRPT) Station for the operational acquisition of Advanced Very High Resolution Radiometer (AVHRR) data. Additionally, DFD functions as a national Processing and Archiving Facility (PAF) for ERS-1/2 data on behalf of ESA. Also, high resolution SAR data from ERS missions can be captured in near-real time by DLR's X-band facilities at the DFD in Neustrelitz, enabling operational derivation of maritime and climatological parameters. This paper describes the value adding processes for the operational derivation of Multichannel Sea Surface Temperatures (MCSST) from NOAA AVHRR data in order to generate daily, weekly and monthly temperature maps of the Mediterranean including the Black Sea, the northeastern Atlantic including the Baltic and North Seas, and the region around Madeira and the Canary Islands. Emphasis is given to special sensor processing steps such as calibration, navigation and cloud-screening for the available products. The ERS SAR is used to derive parameters such as mesoscale wind fields, currents and water levels for the needs of coastal management. Since the SAR works with the same wavelength as the scatterometer, the signal can be evaluated by the same algorithm used for the scayterometer signal (CMOD4 Algorithm from ESA). The wind direction is determined by a method that uses the average direction of wind rows visible on SAR images. Comparisons of wind measurements using recalibrated ERS SAR images to ground truth data are given. Finally, the application potential is outlined and network data distribution, including public access to all products via DLR's Intelligent Satellite Information System (ISIS), are described.