Improvement and comparison of a dynamic tide model in the Elbe Estuary with ERS-2 satellite data

Within the framework of the current cooperation between the Federal Waterway Engineering and Research Institute (BAW) and the German Aerospace Center (DLR) in the Project TIDE, a possible improvement of the boundary conditions of the hydrodynamic tide model TRIM-2D in the Elbe estuary using satellite data is investigated. The model currently uses a bottom topography boundary condition determined by conventional vessel mounted echo sounder measurements, which is difficult and expensive to update. With the aid of Synthetic Aperture Radar (SAR) data of the European Remote Sensing Satellites (ERS-1/2) it can be shown that this intertidal Elbe estuary region underlies a continual change. This is essential for the model performance and has to be taken into account. The major goal of the TIDE project is the operational extraction of shorelines from the SAR data. The shorelines are transformed to isolines of bottom topography which then can be used as model boundary. The transformation is done either by combining the SAR data with conventional tide gauges or with satellite based ERS-2 altimeter data. To derive topography by satellite is much cheaper and less time consuming than conventional methods, but ifs accuracy has still to be validated against them.