Observed space-time structure of radar backscatter from the ocean surface

Space-time radar images of the ocean surface were collected from an airship off the Oregon coast in the fall of 1995, using a coherent, short pulse, HH-polarized X-band system. The radar successfully mapped wind waves, long swell waves and internal wave features. The radar images are converted to two-dimensional spectra of microwave backscatter and the surface velocity field. These spectra are used to examine space-time properties of surface waves. Examples of the radar maps and their corresponding spectra are presented. It is demonstrated that the linear dispersion relation gives the relationship between the time and spatial dependence of the long gravity waves. Also, evident in the spectra are features that don´t obey the linear wave theory