Accession Number : ADA194731

Title :   Some Experiments with Underwater Acoustic Returns from Cylinders Relative to Object Identification for AUV Operation.

Descriptive Note : Master's thesis,

Corporate Author : NAVAL POSTGRADUATE SCHOOL MONTEREY CA

Personal Author(s) : Farren, Maureen A

PDF Url : ADA194731

Report Date : Mar 1988

Pagination or Media Count : 43

Abstract : Object identification and avoidance by an autonomous underwater vehicle requires that a knowledge-based, intelligent control system have some way to quantify sonar returns from an object for comparison with stored data on simple shapes. One measurement of an insonified object is its target strength, which is dependent on geometrical shape and surface properties. This thesis examines various aspects of target strength for two geometrically similar, open-ended cylinders with different expected surface properties. Experimental data was obtained in an anechoic underwater chamber using two acoustic transducers where position of the cylindrical object was varied relative to the transducer's locations. Target strength estimates, as well as propagation time delay of the insonifying signal, were studied. The experimental results were compared to the calculated values of a fully insonified, finite cylinder. Keywords: Object identification; Underwater acoustic imaging; Intelligent control system; Autonomous underwater vehicle; Theses.

Descriptors :   *UNDERWATER VEHICLES, *SONAR SOUND ANALYZERS, *UNDERWATER NAVIGATION, ACOUSTICS, ANECHOIC CHAMBERS, CYLINDRICAL BODIES, DATA STORAGE SYSTEMS, DELAY, ELECTROACOUSTIC TRANSDUCERS, ESTIMATES, EXPERIMENTAL DATA, GEOMETRIC FORMS, IDENTIFICATION, IMAGES, POSITION(LOCATION), PROPAGATION, SONAR, SURFACE PROPERTIES, TARGET STRENGTH, THESES, TIME INTERVALS, UNDERWATER, UNDERWATER EQUIPMENT

Subject Categories : Acoustic Detection and Detectors
      Submarine Engineering
      Underwater and Marine Navigation and Guidance

Distribution Statement : APPROVED FOR PUBLIC RELEASE