Accession Number : ADA323815

Title :   Single Mode Excitation in the Shallow Water Acoustic Channel Using Feedback Control.

Descriptive Note : Doctoral thesis,

Corporate Author : WOODS HOLE OCEANOGRAPHIC INSTITUTION MA

Personal Author(s) : Buck, John R.

PDF Url : ADA323815

Report Date : JUN 1996

Pagination or Media Count : 138

Abstract : The shallow water acoustic channel supports far-field propagation in a discrete set of modes. Ocean experiments have confirmed the modal nature of acoustic propagation, but no experiment has successfully excited only one of the suite of mid-frequency propagating modes propagating in a coastal environment. The ability to excite a single mode would be a powerful tool for investigating shallow water ocean processes. A feedback control algorithm incorporating elements of adaptive estimation, underwater acoustics, array processing and control theory to generate a high-fidelity single mode is presented. This approach also yields a cohesive framework for evaluating the feasibility of generating a single mode with given array geometries, noise characteristics and source power limitations. Simulations and laboratory waveguide experiments indicate the proposed algorithm holds promise for ocean experiments.

Descriptors :   *UNDERWATER ACOUSTICS, ALGORITHMS, COASTAL REGIONS, THESES, FAR FIELD, SHALLOW WATER, FEEDBACK, SOUND TRANSMISSION, ADAPTIVE SYSTEMS, CONTROL THEORY.

Subject Categories : Acoustics

Distribution Statement : APPROVED FOR PUBLIC RELEASE