Use of the distorted wave Born approximation to predict scattering by inhomogeneous objects : application to squid
Jones, Benjamin A.
Lavery, Andone C.
Stanton, Timothy K.
MetadataShow full item record
KeywordAcoustic wave scattering; Approximation theory; Bioacoustics; Computerised tomography; Inhomogeneous media; Underwater sound; Zoology
A new method has been developed to predict acoustic scattering by weakly scattering objects with three-dimensional variability in sound speed and density. This variability can take the form of inhomogeneities within the body of the scatterer and/or geometries where the acoustic wave passes through part of the scattering body, into the surrounding medium, and back into the body. This method applies the distorted wave Born approximation (DWBA) using a numerical approach that rigorously accounts for the phase changes within a scattering volume. Ranges of validity with respect to material properties and numerical considerations are first explored through comparisons with modal-series-based predictions of scattering by fluid-filled spherical and cylindrical fluid shells. The method is then applied to squid and incorporates high resolution spiral computerized tomography (SCT) scans of the complex morphology of the organism. Target strength predictions based on the SCT scans are compared with published backscattering data from live, freely swimming and tethered squid. The new method shows significant improvement for both single-orientation and orientation-averaged scattering predictions over the DWBA-homogeneous-prolate-spheroid model.
Author Posting. © Acoustical Society of America, 2009. This article is posted here by permission of Acoustical Society of America for personal use, not for redistribution. The definitive version was published in Journal of the Acoustical Society of America 125 (2009): 73-88, doi:10.1121/1.3021298.
Suggested CitationJournal of the Acoustical Society of America 125 (2009): 73-88
Showing items related by title, author, creator and subject.
Acoustic mode radiation from the termination of a truncated nonlinear internal gravity wave duct in a shallow ocean area Lin, Ying-Tsong; Duda, Timothy F.; Lynch, James F. (Acoustical Society of America, 2009-10)Horizontal ducting of sound between short-wavelength nonlinear internal gravity waves in coastal environments has been reported in many theoretical and experimental studies. Important consequences arising at the open end ...
Differences between sound scattering by weakly scattering spheres and finite-length cylinders with applications to sound scattering by zooplankton Stanton, Timothy K.; Wiebe, Peter H.; Chu, Dezhang (Acoustical Society of America, 1998-01)A modeling study was conducted to determine the conditions under which fluidlike zooplankton of the same volume but different shapes (spherical/cylindrical) have similar or dramatically different scattering properties. ...
Casey, Kevin D. (Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 1988-06)Two approaches to determining the ocean sound speed profile using measured acoustic modal eigenvalues are examined. Both methods use measured eigenvalues and mode dependent assumed values of the WKB phase integral as ...