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Modeling of shallow water ambient noise directionality using the effective depth approximation

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Date Issued:
1996
Summary:
A theoretical model has been developed to compute the vertical array directional response for surface generated ambient noise in a shallow water environment. The cross spectrum function is based on a normal mode solution to the wave equation in which the effective depth approximation is used to yield closed form solutions for two distinct mode types. The effective depth modes encompass the shallowest grazing angles where the bottom reacts as a pressure release surface to the incident plane waves. The rigid bottom solution takes over as the grazing angle increases and attenuation becomes significant. The computed vertical array beam output was compared to other models including a fast field wavenumber integration method and a multipath eigenray method with mixed results. The results indicated good agreement for both comparisons with the realization that the effective depth model is sensitive to the approximation discontinuity at the mode transition point.
Title: Modeling of shallow water ambient noise directionality using the effective depth approximation.
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Name(s): Galletta, Frank Anton.
Florida Atlantic University, Degree grantor
Glegg, Stewart A. L., Thesis advisor
Type of Resource: text
Genre: Electronic Thesis Or Dissertation
Issuance: monographic
Date Issued: 1996
Publisher: Florida Atlantic University
Place of Publication: Boca Raton, Fla.
Extent: 101 p.
Language(s): English
Summary: A theoretical model has been developed to compute the vertical array directional response for surface generated ambient noise in a shallow water environment. The cross spectrum function is based on a normal mode solution to the wave equation in which the effective depth approximation is used to yield closed form solutions for two distinct mode types. The effective depth modes encompass the shallowest grazing angles where the bottom reacts as a pressure release surface to the incident plane waves. The rigid bottom solution takes over as the grazing angle increases and attenuation becomes significant. The computed vertical array beam output was compared to other models including a fast field wavenumber integration method and a multipath eigenray method with mixed results. The results indicated good agreement for both comparisons with the realization that the effective depth model is sensitive to the approximation discontinuity at the mode transition point.
Identifier: 15237 (digitool), FADT15237 (IID), fau:12008 (fedora)
Collection: FAU Electronic Theses and Dissertations Collection
Note(s): College of Engineering and Computer Science
Thesis (M.S.E.)--Florida Atlantic University, 1996.
Subject(s): Underwater acoustics--Measurement
Noise--Measurement
Acoustic surface waves
Held by: Florida Atlantic University Libraries
Persistent Link to This Record: http://purl.flvc.org/fcla/dt/15237
Sublocation: Digital Library
Use and Reproduction: Copyright © is held by the author, with permission granted to Florida Atlantic University to digitize, archive and distribute this item for non-profit research and educational purposes. Any reuse of this item in excess of fair use or other copyright exemptions requires permission of the copyright holder.
Use and Reproduction: http://rightsstatements.org/vocab/InC/1.0/
Host Institution: FAU
Is Part of Series: Florida Atlantic University Digital Library Collections.