A look at the modal phase structure function in shallow water
| Autor: | Brian Sperry, Jim Lynch |
|---|---|
| Rok vydání: | 1999 |
| Předmět: |
Physics
Acoustics and Ultrasonics business.industry Phase (waves) Mode (statistics) Array processing Correlation function (statistical mechanics) Optics Modal Arts and Humanities (miscellaneous) Range (statistics) Perturbation theory (quantum mechanics) Statistical physics business Coherence (physics) |
| Zdroj: | The Journal of the Acoustical Society of America. 105:1311-1312 |
| ISSN: | 0001-4966 |
| DOI: | 10.1121/1.424785 |
| Popis: | Experimental and theoretical work in shallow‐water acoustic propagation has invariably encountered the complexities of the shallow‐water environment. A useful measure of the propagation complexity for array processing is the ‘‘modal phase structure function.’’ The modal phase structure function makes it possible to study how environmental fluctuations affect point‐to‐point phase differences, quantities which are directly related to modal coherences. A method has been developed, using perturbation theory, that directly relates the modal phase structure function to the environmental sound‐speed correlation function. Despite its relative simplicity, this method can address fully coupled mode range dependence, as well as anisotropy in the environmental correlation function. The phase structure function may be applied to time and frequency coherence problems as well. Another strength of the technique is that contributions from various processes, such as mesoscale and finescale variability, interface roughness and geoacoustic variability, may be separated out under reasonable assumptions. Early calculations show good agreement with experimental results. [Work supported by ONR.] |
| Databáze: | OpenAIRE |
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