Echo statistics of individual and aggregations of scatters in the water column of a random, oceanic waveguide
Author
Jones, Benjamin A.
Colosi, John A.
Stanton, Timothy K.
Date
2014-07Metadata
Show full item recordAbstract
The relative contributions of various physical factors to producing non-Rayleigh distributions of
echo magnitudes in a waveguide are examined. Factors that are considered include (1) a stochastic,
range-dependent sound-speed profile, (2) a directional acoustic source, (3) a variable scattering
response, and (4) an extended scattering volume. A two-way parabolic equation model, coupled
with a stochastic internal wave model, produces realistic simulations of acoustic propagation
through a complex oceanic sound speed field. Simulations are conducted for a single frequency
(3 kHz), monostatic sonar with a narrow beam (5 3 dB beam width). The randomization of the
waveguide, range of propagation, directionality of the sonar, and spatial extent of the scatterers
each contribute to the degree to which the echo statistics are non-Rayleigh. Of critical importance
are the deterministic and stochastic processes that induce multipath and drive the one-way acoustic
pressure field to saturation (i.e., complex-Gaussian statistics). In this limit predictable statistics of
echo envelopes are obtained at all ranges. A computationally low-budget phasor summation
can successfully predict the probability density functions when the beam pattern and number of
scatterers ensonified are known quantities.
Description
The article of record as published may be located at http://dx.doi.org/10.1121/1.4881925
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.Collections
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