Accounting for water-column variability in shallow-water waveguide characterizations based on modal eigenvalues

Journal Article · Mon Sep 06 00:00:00 EDT 2010 · AIP Conference Proceedings

DOI:https://doi.org/10.1063/1.3493103· OSTI ID:21436005

Becker, Kyle M ^[1]; Ballard, Megan S ^[2]

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1. Pennsylvania State University, Applied Research Laboratory, P.O. Box 30, State College, PA 16804-0030 (United States)
2. Applied Research Laboratories, University of Texas at Austin, Austin, TX 78713-8029 (United States)

The influence of water-column variability on the characterization of shallow-water waveguides using modal eigenvalue information is considered. This work is based on the relationship between the acoustic pressure field in shallow water and the depth-dependent Green's function through the Hankel transform. In many practical situations, the Hankel transform can be approximated by a Fourier transform, in which case the Green's function is approximated by a horizontal wave number spectrum with discrete peaks corresponding with individual modal eigenvalues. In turn, the wave number data can be used in inverse algorithms to determine geoacoustic properties of the waveguide. Wave number spectra are estimated from measurements of a point-source acoustic field on a horizontal aperture array in the water column. For range-dependent waveguides, techniques analogous to using a short-time Fourier transform are employed to estimate range-dependent wave number spectra. In this work, water-column variability due to linear internal waves and mesoscale features are considered. It will be shown that these two types of variability impact the estimation of range-dependent modal eigenvalues in different ways. Approaches for accounting for these different types of variability will be discussed as they apply to waveguide characterization.

• OSTI ID: 21436005
• Journal Information: AIP Conference Proceedings, Vol. 1272, Issue 1; Conference: SWAC'09: 2. international shallow-water acoustics conference, Shanghai (China), 16-20 Sep 2009; Other Information: DOI: 10.1063/1.3493103; (c) 2010 American Institute of Physics; ISSN 0094-243X
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ACOUSTICS
ALGORITHMS
EIGENVALUES
FOURIER TRANSFORMATION
GREEN FUNCTION
HANKEL TRANSFORM
INTERNAL WAVES
WATER
WAVE EQUATIONS
WAVEGUIDES
DIFFERENTIAL EQUATIONS
EQUATIONS
FUNCTIONS
HYDROGEN COMPOUNDS
INTEGRAL TRANSFORMATIONS
MATHEMATICAL LOGIC
OXYGEN COMPOUNDS
PARTIAL DIFFERENTIAL EQUATIONS
TRANSFORMATIONS