The fading of a monochromatic acoustic plane wave, reradiated by a moving, rough surface, is described using the far-zone spectral density of the reradiated pressure. This quantity is calculated using the method of physical optics, and specialized to the cases of slightly rough and very rough wind-generated seas, which are described by the Neumann-Pierson directional wave spectrum. The results show the dependence of the radiation spectrum upon wind speed, and the angles of incidence and observation relative to the wind direction. Author
Prepared in cooperation with Western Electric Co., Inc., New York.