Monitoring river estuaries and coastal areas using TerraSAR-X

Morphological changes in coastal areas, especially in river estuaries, are of high interest in many parts of the world. A new X-band radar on board the TerraSAR-X satellite gives access to spatial resolution as fine as 1 m. In Spotlight (SL) mode, resolution is down to 1.7 m in azimuth, with 10 times 10 km coverage. Spotlight is the best choice to monitor river estuaries, river channels, and bathymetry. Stripmap (SM) mode with a resolution down to 3.3 m and a swath width around 30 km is a perfect tool to investigate morphological features, such as coastline changes or wadden sea areas. ScanSAR (SC) mode with a resolution as fine as 18 m and spatial coverage of 150 times 100 km is also used for remote sensing of coastal region and open seas. Several polarization modes allow better separation of land and water areas. For assessing the suitability of remote sensing satellite data (TerraSAR-X) to detect morphological changes, the highly morphodynamic area of the river Elbe estuary has been chosen. Morphological changes related to sedimentation, erosion and redeposition is shown by analysing in-situ data. Moreover, bottom topography retrieval can be quite efficiently demonstrated by using TerraSAR-X data compared to 1 arc-minute global relief model (ETOPO1).