Underwater Bottom-Topography in coastal areas from TerraSAR-X data

Abstract

In this paper, wave refraction and shoaling in coastal areas are investigated and used to derive the bathymetry. Due to its high spatial resolution, which can achieve up to 1m in Spotlight mode, and its low cut-off wavelength, images from the TerraSAR-X satellite are particular suitable for the observation of wave behavior in transient and shallow water. By computing the two dimensional spectra shoaling waves are tracked from the open sea up to the shoreline. The observed wave refraction and shoaling is compared with wave refraction laws and first order wave theory (Airy Theory). The retrieved bathymetry is compared against depth data from other sources like ETOPO1, US Coastal Relief Model and sea charts from the British Admiralty. Another goal of this paper is the investigation of breaking waves showing up as near shore image patterns. A theory is presented how to derive the height of breaking waves by use of this pattern. SAR images with azimuth as well as range traveling waves are investigated. As test sites the entrance of Port Phillip near Melbourne (Australia) and the Duck Research Pier in North Carolina (USA) are chosen.