The processing of data from multi-hydrophone towed arrays of uncertain shape
The processing of data from multi-hydrophone towed arrays of uncertain shape
An array of omni-directional hydrophones in tow to locate distant sources of acoustic radiation.
Where it is impossible, either actually or virtually, either to rotate the antenna or to change its shape, it is expedient to maximize the parallactic angle of point source and antenna through lengthening the antenna, and, since the antenna in question is implemented in the form of a string of discrete elements, to maximize the noise-rejective potential of the antenna by maximizing the number of elements in the string.
Although a priori the placing of hydrophones in an array is influenced by an uncertainty in knowledge of array disposition, an uncertainty which increases with distance from the towing vessel, for convenience an actual array with hydrophones spaced equidistantly is assumed for most of the thesis, although a modicum of flexibiltiy of the antenna is allowed. In practice, the appropriateness or otherwise of a particular disposition of hydrophones is a function of the actual location and spectral character of a source.
In virtue of the uncertainty of sensor location as well as a modest relative motion of source and array, phase-differences of signal, reflected by measured pressures compared between hydrophones, are surmised in terms of bands of tolerance. It is shown that three such phase `bins' per wavelength is optimal in a novel method presented in the thesis for comparing and contrasting the contents of bins such that a maximum may be associated uniquely with the location of a source.
The thesis is submitted with the conviction that a practical solution to a contemporary given problem of `fuzzy' instrumentation has been found, a solution elaborated upon a theoretical basis with which, taking account of modern facilities for practical implementation, advances in accuracy and speed of processing beyond existing limits may be achieved.
University of Southampton
Sweet, Geoffrey William
49d5d738-8698-4185-83a6-3caeb534c2f4
1993
Sweet, Geoffrey William
49d5d738-8698-4185-83a6-3caeb534c2f4
Sweet, Geoffrey William
(1993)
The processing of data from multi-hydrophone towed arrays of uncertain shape.
University of Southampton, Doctoral Thesis.
Record type:
Thesis
(Doctoral)
Abstract
An array of omni-directional hydrophones in tow to locate distant sources of acoustic radiation.
Where it is impossible, either actually or virtually, either to rotate the antenna or to change its shape, it is expedient to maximize the parallactic angle of point source and antenna through lengthening the antenna, and, since the antenna in question is implemented in the form of a string of discrete elements, to maximize the noise-rejective potential of the antenna by maximizing the number of elements in the string.
Although a priori the placing of hydrophones in an array is influenced by an uncertainty in knowledge of array disposition, an uncertainty which increases with distance from the towing vessel, for convenience an actual array with hydrophones spaced equidistantly is assumed for most of the thesis, although a modicum of flexibiltiy of the antenna is allowed. In practice, the appropriateness or otherwise of a particular disposition of hydrophones is a function of the actual location and spectral character of a source.
In virtue of the uncertainty of sensor location as well as a modest relative motion of source and array, phase-differences of signal, reflected by measured pressures compared between hydrophones, are surmised in terms of bands of tolerance. It is shown that three such phase `bins' per wavelength is optimal in a novel method presented in the thesis for comparing and contrasting the contents of bins such that a maximum may be associated uniquely with the location of a source.
The thesis is submitted with the conviction that a practical solution to a contemporary given problem of `fuzzy' instrumentation has been found, a solution elaborated upon a theoretical basis with which, taking account of modern facilities for practical implementation, advances in accuracy and speed of processing beyond existing limits may be achieved.
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Published date: 1993
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Local EPrints ID: 462796
URI: http://eprints.soton.ac.uk/id/eprint/462796
PURE UUID: 5891d2e7-2e3a-434f-83aa-8bfe4e342238
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Date deposited: 04 Jul 2022 20:04
Last modified: 16 Mar 2024 18:58
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Author:
Geoffrey William Sweet
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