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| Content Provider | IEEE Xplore Digital Library |
|---|---|
| Author | Ohta, K. Frisk, G.V. |
| Copyright Year | 1976 |
| Abstract | In a shallow-water ocean environment, the range dependent variation of the geoacoustic properties of the seabed is one of the crucial factors affecting sound propagation. Since the local modes of propagation depend on the spatial changes in the bottom sediments, the local eigenvalues of these modes are useful as tools for examining the range dependence of the sediment properties. In order to extract the local eigenvalues from measurements of the pressure field in a laterally inhomogeneous waveguide, the zeroth-order asymptotic Hankel transform with a short sliding window is utilized. The local peak positions in the output spectra differ from the local eigenvalues due to both the range variation of the local modes and the interference of adjacent modes. The departure due to the former factor is evaluated analytically by using the stationary phase method. In order to reduce the error induced by the latter factor, mode filtering is utilized by incorporating data from a fixed vertical array of receivers. The methods developed are applied to simulated pressure field data as well as experimental field data, and it is shown that the range evolution of the local modes can be successfully estimated. In addition, field measurements are used to demonstrate that the modal trajectories in range can be used to infer the range-dependent geoacoustic properties of the seabed. |
| Sponsorship | IEEE Oceanic Engineering Society |
| Starting Page | 501 |
| Ending Page | 521 |
| Page Count | 21 |
| File Size | 1060689 |
| File Format | |
| ISSN | 03649059 |
| Volume Number | 22 |
| Issue Number | 3 |
| Language | English |
| Publisher | Institute of Electrical and Electronics Engineers, Inc. (IEEE) |
| Publisher Date | 1997-07-01 |
| Publisher Place | U.S.A. |
| Access Restriction | One Nation One Subscription (ONOS) |
| Rights Holder | Institute of Electrical and Electronics Engineers, Inc. (IEEE) |
| Subject Keyword | Eigenvalues and eigenfunctions Sea measurements Acoustic propagation Acoustic waveguides Oceans Underwater acoustics Optical reflection Sediments Acoustic reflection Acoustic waves |
| Content Type | Text |
| Resource Type | Article |
| Subject | Ocean Engineering Mechanical Engineering Electrical and Electronic Engineering |
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