A Synopsis of Research on Subbottom Effects on Underwater Acoustic Propagation.
Abstract
This report investigates some effects of the subbottom on underwater acoustic propagation. Our major accomplishment was solving the problem of ordering and counting the normal modes of propagation in the ocean waveguide when the seafloor is described by an impedance boundary condition. The boundary condition, derived from the plane wave reflection coefficient, introduces mathematical complexities since it is a function of the separation parameter in the acoustic wave equation. As a natural extension of our theoretical approach, the relationship between mode concepts of normalization and cycle distance, and geometrical ray concepts of beam displacement and time delay were rigorously established. Additional work was also done to examine ray and normal mode approaches for predicting propagation in a sloping geometry. Keywords: Normal mode; Shallow water; Beam displacement; Slope; Impedance boundary condition; Low frequency; Seafloor; Beam time delay.
Document Details
- Document Type
- Technical Report
- Publication Date
- Nov 14, 1985
- Accession Number
- ADA165420
Entities
People
- Jo B. Lindberg
- Paul J. Vidmar
- Robert A. Koch
Organizations
- University of Texas at Austin