Sea state measurements using TerraSAR-X data

Abstract

Synthetic Aperture Radar (SAR) is a unique sensor able to provide two dimensional information on meteo-marine parameters of the ocean surface e.g. wind speed and wave height. We present an algorithm (XWAVE) to derived significant wave height (H s from TerraSAR-X (TS-X) data without the need of a priori information. The algorithm is based on spectral analyses of TS-X data, using a Geophysical model function, the coefficients are fitted to collocated in-situ buoy measurements using the least squares method. Wind speed information provided by the wind speed estimation XMOD algorithm [1] is combined in the XWAVE algorithm as well. Sea state parameters derived from TS-X data using the proposed algorithm have been compared to in-situ buoy measurements. Additionally, the one dimensional spectra are compared to the wave spectrum provided by the one given by the NOOA buoys. The SAR wave peak direction is also compared to the wave peak direction given by directional buoys. Sea state properties in coastal areas change rapidly in the spatial domain. TS-X data are especially suitable for the study of sea state variability in coastal areas due to its high resolution. Coastal wave fields have been derived from TS-X data and verified with numerical wave model results and with in-situ buoy measurements for the collated point in the area of the North Sea.