Radar signatures of the sea bed in coastal waters

The knowledge of the imaging mechanisms of submarine bedforms based on the functional dependence of the interaction between the current and water surface roughness on meteorological, oceanographic, and radar parameters was improved during recently conducted experiments. Within the framework of the Marine Science and Technology Program (MAST-I) during 1990-1992 of the Commission of the European Communities a group of several institutes in Europe has investigated the mapping of sea bottom topography in a multi-sensor approach for morphodynamic studies off the Dutch coast. During the SAR and X-Band Ocean Nonlinearities Research Platform North Sea (SAXON-FPN) Experiment in 1990 one aim was to improve the understanding of the hydrodynamics due to the sea bed. Within this project oceanographic, meteorological and remotely sensed shipborne radar data of a nonlinear flow regime were simultaneously observed and analysed. The maximum radar cross-section modulation caused by the sand waves in the MAST-I study area is about 3 dB and is located at the downstream end of the steep slope. A strong current-wave interaction creates the roughness modulation in the SAXON-FPN study area