Extraction of wave field from TerraSAR-X data

Kurzfassung

The new X-band Synthetic Aperture Radar (SAR) onboard the satellite TerraSAR-X (TSX) was launched on June 15, 2007. Since then it has provided numerous high quality data over land and ocean operationally. In the present study, integral wave parameters and two-dimensional ocean wave spectra are extracted from TerraSAR-X data. The preliminary results are compared to numerical wave models results, coastal X-band marine radar WaMoS (Wave and Surface Current Monitoring System) data. We developed an empirical geophysical model function (XWAVE) to derive significant wave height from TerraSAR-X data without using prior information. The comparison shows that the empirical model can yield reliable sea state measurements up to 5 m significant wave height. The model can be used for the near real-time services to deliver sea state measurements from high resolution TerraSAR-X data. Cross spectra are extracted from TerraSAR-X SSC (Single look Slant range Complex) products to remove the 180° ambiguity for wave propagation direction. A positive peak in the imaginary part of the cross spectrum indicates the ocean wave traveling direction. Peak wavelength is determined as well from the cross spectrum and compared to the WaMoS marine radar at Ekofisk oil platform in the North Sea is chosen as a test site.