Accession Number : ADA270465


Title :   Passive Localization of Underwater Acoustic Beacons


Descriptive Note : Master's thesis


Corporate Author : WOODS HOLE OCEANOGRAPHIC INSTITUTION MA


Personal Author(s) : Wojcik, Dennis M


Full Text : http://www.dtic.mil/dtic/tr/fulltext/u2/a270465.pdf


Report Date : Sep 1993


Pagination or Media Count : 222


Abstract : 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.


Descriptors :   *HYDROPHONES , *UNDERWATER ACOUSTICS , *SONAR BEACONS , MAXIMUM LIKELIHOOD ESTIMATION , BEARING(DIRECTION) , MOVING TARGETS , THESES , ACOUSTIC VELOCITY , SYNTHETIC APERTURE SONAR , DESIGN CRITERIA , RANGE FINDING , MONTE CARLO METHOD , ACOUSTIC ARRAYS , ACOUSTIC SIGNALS


Subject Categories : Acoustic Detection and Detectors


Distribution Statement : APPROVED FOR PUBLIC RELEASE