Propagation and Scattering in Layers with Rough Interfaces: Shallow Water Acoustics
Abstract
LONG-TERM GOAL. This research is being pursued in order provide good approximations for the behavior of acoustic fields propagating in layers bounded by statistically rough interfaces and to understand the importance of multiple scattering between interfaces. SCIENTIFIC OBJECTIVE. The immediate scientific objective of this research is to develop improved methods for computing the mean and the second moments of acoustic fields in waveguides with rough boundaries. Of particular concern is the problem of surface scattered fields returning to interact with a scattering interface many times. A secondary objective is to determine how to incorporate non-perturbative scattering amplitudes which have been developed for half-space scattering into the description of scattering in a waveguide where plane-waves do not provide a natural description of propagation. APPROACH. In a waveguide with many interfaces, the net field incident on one particular interface is the result of adding the field arising directly from any sources and the field which is multiply reflected and scattered from the remainder of the waveguide. The scattered field is determined by this net incident field plus the result of this field after it has been multiply scattered. To describe this complicated situation I have developed a compact formulation of the scattering in a waveguide with arbitrary sound speed profile which uses impedance operators to describe the effects of rough interfaces. This formulation is analogous to multiple scattering formalisms used in solid state physics to describe electron localization, and I have been able to adapt the methods used there to multimodal propagation in waveguides.
Document Details
- Document Type
- Technical Report
- Publication Date
- Sep 30, 1997
- Accession Number
- ADA634305
Entities
People
- David H. Berman
Organizations
- University of Iowa