On the Use of Multi-frequency Sar Imagery for a Surveillance of the Wadden Sea Ecosystem on the German North Sea Coast

High-resolution multispectral remote sensing data from satellite-borne optical sensors have already been used for the classification of sediments, macrophytes, and mussels in the German Wadden Sea. Since the use of those sensors in northern latitudes is strongly limited by clouds and haze, we included synthetic aperture radar (SAR) data, allowing earth observation that is independent of cloud coverage and daytime. The data acquired at different radar bands (L, C, and X band, from ALOS PALSAR, ERS SAR and ENVISAT ASAR, and TerraSAR-X , respectively) have been used to analyse their potential for crude sediment classification on dry-fallen intertidal flats and for detecting benthic fauna such as blue mussel or oyster beds. The information gained from optical and SAR sensors, together with in-situ observations, will yield an improved classification of different sediment types, together with mussel beds and sea grass.