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DIRECTION OF ARRIVAL ESTIMATION IN PASSIVE SONAR

Since World War I, the area of acoustic undersea warfare has witnessed several research
activities targeting the development of advanced systems to accurately detect and localize
underwater moving targets. One of the main categories of these systems is the passive sound
navigation and ranging (SONAR) that searches for the location of the ships and submarines by
listening to the radiated noise produced by their propellers, machinery, and flow dynamics. The
performance of the passive sonar highly depends on the particular array signal processing
algorithms used in practice. Presently, one of the main challenges is to accurately estimate the
target direction of arrival (DOA) in severe underwater environments.
This thesis is proposed to enhance the DOA estimation in two distinct applications. This first
application is to improve the spatial resolution of the uniform linear towed arrays. This is done by
applying new spatial extrapolation techniques called 2D- and 3D- fast orthogonal search (FOS)
for both uniform linear and rectangular arrays, respectively. The presented methods show better
performance than the conventional methods with respect to signal to noise ratio (SNR), number
of snapshots and angular separation. Moreover it reduces the computational complexity required
by the spatial extrapolation methods based on linear prediction approach.
The other application concerns with developing a new DOA estimation that provides better
spatial spectrum than the one provided by conventional beamforming (CBF) when a nonuniform
linear array of directional frequency analysis and recording (DIFAR) sonobuoys is
employed. The introduced technique or the so called fourth order cumulant beamforming (FOCBF)
and shows an outstanding performance compared to CBF especially in low SNR.
Furthermore, a warping FOC-BF (WFOC-BF) method obtained by augmenting a warping
beamforming technique with FOC-BF is proposed to reduce the required computational
complexity by FOC-BF while preserving the same performance. / Thesis (Ph.D, Electrical & Computer Engineering) -- Queen's University, 2012-06-27 14:59:33.941

Identiferoai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:OKQ.1974/7294
Date27 June 2012
CreatorsMassoud, ALI
ContributorsQueen's University (Kingston, Ont.). Theses (Queen's University (Kingston, Ont.))
Source SetsLibrary and Archives Canada ETDs Repository / Centre d'archives des thèses électroniques de Bibliothèque et Archives Canada
LanguageEnglish, English
Detected LanguageEnglish
TypeThesis
RightsThis publication is made available by the authority of the copyright owner solely for the purpose of private study and research and may not be copied or reproduced except as permitted by the copyright laws without written authority from the copyright owner.
RelationCanadian theses

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