Echo statistics of individual and aggregations of scatters in the water column of a random, oceanic waveguide
Jones, Benjamin A.
Colosi, John A.
Stanton, Timothy K.
MetadataShow full item record
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.
The article of record as published may be located at http://dx.doi.org/10.1121/1.4881925
RightsThis 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.
Showing items related by title, author, creator and subject.
Humara, Michael Jesus (Monterey California. Naval Postgraduate School, 2020-05);Developing accurate and computationally efficient models for ocean acoustics is inherently challenging due to several factors including the complex physical processes and the need to provide results on a large range of ...
Goodman, Alvin S.; Lewis, Peter A. W.; Robbins, Herbert E. (Monterey, California. Naval Postgraduate School, 1971-12); NPS55LW71122AThe large random access memory and high internal speeds of present day computers can be used to increase the efficiency of large-scale simulation experiments by estimating simultaneously several quantiles of each of several ...
Hashad, Atalla I. (Monterey, California. Naval Postgraduate School, 1994-12);Fundamental results developed by Wiener in the 1950's are combined with new work in the area of higher-order statistics to develop and explore a general model for nonlinear stochastic processes. The Wiener model is developed ...