| Abstrakt: |
A technique for studying wave scattering from randomly rough surfaces by computer simulation is presented. Scattering of 1.0- and 1.5-kHz acoustic waves from numerical models of wind-driven sea surfaces having Neumann-Pierson spectra for a 5 m sec-1 wind speed is reported. The surfaces were generated using the theory of linear systems in two dimensions. Scattering was simulated by forming facets in the surface, applying laws of reflection at each facet, and accumulating the rays, with due regard to phase and spreading, onto a rectangular grid of 63 simulated hydrophones. The results are presented in terms of total, coherent, and incoherent intensities, amplitude and phase fluctuations, and degree of coherence all in specular and nonspecular directions, and spatial correlations in horizontal and vertical directions. Also presented is a study of incoherent sea-surface scattering of high-frequency waves emitted from a point source at infinity and having various position angles with respect to the zenith and the wind direction on the surface. [ABSTRACT FROM AUTHOR] |
