Passive localization of underwater acoustic beacons.

458 Pages·1993·10.5 MB·en_US

by  Wojcik, Dennis Michael.

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PASSIVE LOCALIZATION OF UNDERWATER
ACOUSTIC BEACONS
by
Dennis Michael Wojcik
B.S. Electrical Engineering
Marquette University (1986)
Submitted to the
Massachusetts Institute of Technology/
Woods Hole Oceanographic Institution
Joint Program in Oceanography and
Applied Ocean Science and Engineering in
Partial Fulfillment of the Requirements of the Degree of
Master of Science in Oceanographic Engineering
at the
Massachusetts Institute of Technology and the
Woods Hole Oceanographic Institution
September 1993
© Dennis Michael Wojcik 1993
The author hereby grants to the Massachusetts Institute of Technology,
the Woods Hole Oceanographic Institution, and the U.S. Government
permission to reproduce and distribute copies of this thesis in whole or in part.

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93943-5101
PASSIVE LOCALIZATION OF UNDERWATER
ACOUSTIC BEACONS
by
Dennis Michael Wojcik
B.S. Electrical Engineering
Marquette University (1986)
Submitted to the Massachusetts Institute of Technology/
Woods Hole Oceanographic Institution Joint Program in
Oceanography and Applied Ocean Science and Engineering in
Partial Fulfillment of the Requirements of the Degree of
Master of Science in Oceanographic Engineering
This thesis examines the use of a single, omnidirectional hydrophone as a
receiving sensor to passively localize an acoustic beacon. The localization problem is
presented as a constrained, nonlinear parameter estimation problem, and Lagrange
multipliers are introduced to solve for the maximum likelihood estimate of the acoustic
beacon's position. An iterative algorithm is developed using range difference
measurements to solve for the maximum likelihood estimate of a stationary acoustic
beacon's position. This algorithm is then extended to include linear, constant velocity
motion of the acoustic beacon. Finally, design specifications for a receiver to
implement the maximum likelihood estimation algorithms are developed.
To test the maximum likelihood estimate algorithms, Monte Carlo simulations
are conducted. Results from six representative scenarios are presented. Test results
show that as the number of range differences used increases, or the distance that the
observer travels between received beacon signals increases, the accuracy of the
estimated position improves. Also, tests show that accuracy of the estimated beacon
position is directly related to the accuracy in which the observer's position is
measured. To test the receiver's design specifications, a prototype receiver is built
using commonly available components. It is then shown that the prototype receiver
meets or exceeds the design specifications.