Advanced Search

Acoustic scattering by axisymmertic finite-length bodies with application to fish : measurement and modeling

Research and Teaching Output of the MIT Community

Show simple item record

dc.contributor.advisor Timothy K. Stanton. en_US Reeder, D. Benjamin (Davis Benjamin), 1966- en_US
dc.contributor.other Woods Hole Oceanographic Institution. en_US 2005-10-14T19:27:35Z 2005-10-14T19:27:35Z 2002 en_US 2002 en_US
dc.description Thesis (Ph. D.)--Joint Program in Applied Ocean Physics and Engineering (Massachusetts Institute of Technology, Dept. of Ocean Engineering and the Woods Hole Oceanographic Institution), 2002. en_US
dc.description Includes bibliographical references (leaves 140-148). en_US
dc.description.abstract This thesis investigates the complexities of acoustic scattering by finite bodies in general and by fish in particular through the development of an advanced acoustic scattering model and detailed laboratory acoustic measurements. A general acoustic scattering model is developed that is accurate and numerically efficient for a wide range of frequencies, angles of orientation, irregular axisymmetric shapes and boundary conditions. The model presented is an extension of a two-dimensional conformal mapping approach to scattering by irregular, finite-length bodies of revolution. An extensive series of broadband acoustic backscattering measurements has been conducted involving alewife fish (Alosa pseudoharengus), which are morphologically similar to the Atlantic herring (Clupea harengus). A greater-than-octave bandwidth (40-95 kHz), shaped, linearly swept, frequency modulated signal was used to insonify live, adult alewife that were tethered while being rotated in 1-degree increments over all angles of orientation in two planes of rotation (lateral and dorsal/ventral). Spectral analysis correlates frequency dependencies to morphology and orientation. Pulse compression processing temporally resolves multiple returns from each individual which show good correlation with size and orientation, and demonstrate that there exists more than one significant scattering feature in the animal. en_US
dc.description.abstract (cont.) Imaging technologies used to exactly measure the morphology of the scattering features of fish include very high-resolution Phase Contrast X-rays (PCX) and Computerized Tomography (CT) scans, which are used for morphological evaluation and incorporation into the scattering model. Studies such as this one, which combine scattering models with high-resolution morphological information and high-quality laboratory data, are crucial to the quantitative use of acoustics in the ocean. en_US
dc.description.statementofresponsibility by D. Benjamin Reeder. en_US
dc.format.extent 148 leaves en_US
dc.format.extent 5018894 bytes
dc.format.extent 5018703 bytes
dc.format.mimetype application/pdf
dc.format.mimetype application/pdf
dc.language.iso eng en_US
dc.publisher Massachusetts Institute of Technology en_US
dc.rights M.I.T. theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission. See provided URL for inquiries about permission. en_US
dc.subject Ocean Engineering. en_US
dc.subject Joint Program in Applied Ocean Physics and Engineering. en_US
dc.subject Woods Hole Oceanographic Institution. en_US
dc.title Acoustic scattering by axisymmertic finite-length bodies with application to fish : measurement and modeling en_US
dc.type Thesis en_US Ph.D. en_US
dc.contributor.department Massachusetts Institute of Technology. Dept. of Ocean Engineering. en_US
dc.contributor.department Joint Program in Applied Ocean Physics and Engineering. en_US
dc.contributor.department Woods Hole Oceanographic Institution. en_US
dc.identifier.oclc 51758176 en_US

Files in this item

Name Size Format Description
51758176-MIT.pdf 7.049Mb PDF Full printable version

This item appears in the following Collection(s)

Show simple item record