Use of the Wavenumber Technique with the Lloyds Mirror for an Acoustic Doublet.

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Authors
King, Portia Baird
Subjects
Lloyds mirror
underwater acoustics
fast Fourier transform
wavenumber technique
pressure spectrum
source depth determination
acoustic propagation
ASW
isospeed environment
Advisors
Coppens, A.B.
Dunlap, C.R.
Date of Issue
1985-03
Date
March 1985
Publisher
Monterey, California. Naval Postgraduate School
Language
en_US
Abstract
This thesis examines a method to determine the depth of a point source in an isospeed ocean environment. Using the Fourier Transform on the acoustic pressure field in the range domain results in the attainment of the acoustic pressure spectrum in the wavenumber domain and a characteristic nodal spacing unique to the source-receiver depths. Quantitative examination of a magnitude plot of the spectrum and use of simple mathematical formulae yield the source depth. The debilitative effects of narrowband noise and surface roughness on the pressure spectrum are also examined. The pressure spectrum is recognizable in noise after the pressure field in the range domain has been lost in the noise field. The effect of surface gravity waves on the pressure spectrum is similar to that on the pressure field in the range domain: the characteristic nodal spacing is suppressed as the height of the surface waves increases.
Type
Thesis
Description
Series/Report No
Department
Antisubmarine Warfare Academic Group
Organization
Naval Postgraduate School (U.S.)
Identifiers
NPS Report Number
Sponsors
Funder
Format
Citation
Distribution Statement
Approved for public release; distribution is unlimited.
Rights
This publication is a work of the U.S. Government as defined in Title 17, United States Code, Section 101. Copyright protection is not available for this work in the United States.
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