Temporal coherence of the acoustic field forward propagated through a continental shelf with random internal waves
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Makris_Temporal coherence.pdf
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1.32 MB
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4a613a65bac813c7ca68d1f226b01c64
Author(s)
Gong, Zheng
Chen, Tianrun
Ratilal, Purnima
Makris, Nicholas
Date Issued
September 2013
Journal
The Journal of the Acoustical Society of America
Publisher
Acoustical Society of America (ASA)
Citation
Gong, Zheng, Tianrun Chen, Purnima Ratilal, and Nicholas C. Makris. “Temporal Coherence of the Acoustic Field Forward Propagated through a Continental Shelf with Random Internal Waves.” The Journal of the Acoustical Society of America 134, no. 5 (2013): 3476. © 2013 Acoustical Society of America
Version
Final published version
Abstract
An analytical model derived from normal mode theory for the accumulated effects of range-dependent multiple forward scattering is applied to estimate the temporal coherence of the acoustic field forward propagated through a continental-shelf waveguide containing random three-dimensional internal waves. The modeled coherence time scale of narrow band low-frequency acoustic field fluctuations after propagating through a continental-shelf waveguide is shown to decay with a power-law of range to the −1/2 beyond roughly 1 km, decrease with increasing internal wave energy, to be consistent with measured acoustic coherence time scales. The model should provide a useful prediction of the acoustic coherence time scale as a function of internal wave energy in continental-shelf environments. The acoustic coherence time scale is an important parameter in remote sensing applications because it determines (i) the time window within which standard coherent processing such as matched filtering may be conducted, and (ii) the number of statistically independent fluctuations in a given measurement period that determines the variance reduction possible by stationary averaging.
MIT Department
Massachusetts Institute of Technology. Department of Earth, Atmospheric, and Planetary Sciences
Massachusetts Institute of Technology. Department of Mechanical Engineering
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Article is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use.
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DOI of Published Version
https://doi.org/10.1121/1.4824157
