Abstract:

The performance of active, multistatic sonar systems can be enhanced significantly, if the 3-dimensional environmental physics is incorporated into the processing. Thus fundamental understanding of the difference between target scattering and bottom reverberation could provide the basis for advanced, multistatic clutter reduction. Strong bottom interaction is the most distinct acoustic feature in shallow-water environments. Consequently, bottom roughness becomes the major reverberation mechanism limiting sonar system performance. To investigate the three-dimensional spatial characteristics of multistatic target scattering and bottom reverberation, a unified numerical model is being developed. It combines existing theoretical models for scattering from shells of finite length, anisotropic interface scattering and seismo-acoustic wave propagation in stratified media. The model generates Monte Carlo statistics for multistatic target scattering in the presence of a strongly reverberant, rough elastic bottom. The effects of anisotropic statistics of the bottom roughness on the multistatic field are investigated, and the significance of the geometric and acoustic properties of target is addressed. [Work supported by ONR.]