摘要 : The effects on surface-generated ambient noise of medium inhomogenieties caused by small sound-speed perturbation are considered. A noise-generation model combined with the wave propagation solution in a random medium is applied t... 展开 The effects on surface-generated ambient noise of medium inhomogenieties caused by small sound-speed perturbation are considered. A noise-generation model combined with the wave propagation solution in a random medium is applied to a typical oceanic environment to study the characteristics of the surface-generated noise field. Based upon leading-order analysis, the effects of medium inhomogeneities on the noise field, including the wavenumber spectrum, noise intensity, and spatial correlation, are analyzed. The results show that the sound-speed perturbations have an effect equivalent to that of medium absorption so that the efficiency of waveguide propagation is degraded. In particular, the normal modes become less prominent, which in turn reduces the noise intensity in the waveguide. Furthermore, the spatial coherence of the noise field decreases with increasing randomness in the medium, indicating that the coherence of the noise field is partly attributable to the characteristics of the medium inhomogenieties. 收起