Synthetic aperture radar observation of ocean surface

To analyze the coastal environment, the ocean surface wind field with high spatial resolution is one of important factors. The high spatial resolution of SAR agrees well to measure the wind field in coastal ocean. In this paper, the dependency of the normalized radar cross section in the X - and L-band on wind direction is analyzed under high and low wind speed conditions. As a result of this study, the dependencies of the NRCS in the X-band on the wind direction represent different features between the parallel polarizations. The difference of dependencies of the NRCS on the relative wind direction suggests the possibility of the wind measurement using an X-band polarimetric SAR. Moreover the difference of the dependency between the radar frequencies also suggests the ocean wind measurements by a dual-frequency SAR.