Accession Number : ADA190008

Title :   Target Localization in an Inhomogeneous Medium.

Descriptive Note : Master's thesis,

Corporate Author : NAVAL POSTGRADUATE SCHOOL MONTEREY CA

Personal Author(s) : Budney, Michael D

PDF Url : ADA190008

Report Date : Dec 1987

Pagination or Media Count : 64

Abstract : A computer algorithm was developed to determine if an acoustic transmitter can be localized based on estimates of local angles of arrival of acoustic signals incident upon a receive planar sonar array, knowledge of the deterministic effects of the ocean on sound propagation, and local sound-speed profiles of the ocean. The algorithm was designed to determine azimuthal and elevation/depression angles to the transmitter as well as computing the depth, range, cross range, and line-of-sight range separations between the transmitter and the receive array. The algorithm utilizes ray acoustics and model-based phase weights to determine the transmitter's location relative to the receive array's position. As written, the algorithm is capable of solving localization problems in which the transmitter and receiver are in the same gradient of the local sound-speed profile, provided that the range from transmitter to receiver is not so great that the acoustic signal passes through a turning point prior to reaching the receive array. The results indicate that the method proposed is viable for the class of problems for which it was designed, and accuracies on the order of 0.1 meters are obtained for line-of-sight ranges on the order of several kilometers.

Descriptors :   *ACOUSTIC SIGNALS, *COMPUTER APPLICATIONS, *DEPRESSION ANGLES, *SONAR ARRAYS, *SOUND TRANSMISSION, *TRANSMITTERS, ACOUSTIC EQUIPMENT, ACOUSTIC VELOCITY, ACOUSTICS, ALGORITHMS, ANGLES, ARRAYS, AZIMUTH, DETERMINANTS(MATHEMATICS), ELEVATION, LINE OF SIGHT, OCEANS, PLANAR STRUCTURES, POSITION(LOCATION), PROFILES, SEPARATION, TRANSMITTER RECEIVERS

Subject Categories : Acoustic Detection and Detectors
      Acoustics
      Computer Programming and Software
      Target Direction, Range and Position Finding

Distribution Statement : APPROVED FOR PUBLIC RELEASE