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dc.contributor.advisorHofler, Thomas J.
dc.contributor.advisorRice, Joseph A.
dc.contributor.authorSineiro, Guilherme da Silva
dc.date.accessioned2012-03-14T17:47:54Z
dc.date.available2012-03-14T17:47:54Z
dc.date.issued2003-12
dc.identifier.urihttp://hdl.handle.net/10945/6143
dc.description.abstractAn underwater piezoelectric directional transducer prototype, to be used in underwater acoustic networks, combines different vibration modes of a cylinder to synthesize desired beam patterns. Performance is evaluated in an anechoic water tank, with reference hydrophones and a signal analyzer capable of Fast Fourier Transform (FFT) data processing. An impulse technique is used for measuring impedance, admittance, Transmitted Voltage Response (TVR), Receiving Voltage Sensitivity (RVS), and horizontal and vertical beam patterns. In this technique, a single-cycle tone burst is emitted at a low frequency repetition rate and excites the driving transducer. The signal analyzer excludes the acoustic reverberations from the tank walls by adequate adjusting of the FFT sampling window. Additionally, for beam-pattern data acquisition, a computer simultaneously samples the azimuthal orientation of the prototype relative to a reference hydrophone and the corresponding frequency response, as the evaluated transducer continuously rotates. The FFT capability of the signal analyzer also supports intrinsic noise evaluation. The results show that the new transducer architecture is capable of producing directional beam patterns according to the present operational requirements by electronic control of the internal electrode applied voltage distribution.en_US
dc.description.urihttp://archive.org/details/underwatermultim109456143
dc.format.extentxii, 55 p. : ill. (chiefly col.) ;en_US
dc.publisherMonterey, California. Naval Postgraduate Schoolen_US
dc.rights Copyright is reserved by the copyright owner.en_US
dc.subject.lcshUnderwater acousticsen_US
dc.subject.lcshUnderwater acoustic telemetryen_US
dc.subject.lcshTransducersen_US
dc.titleUnderwater multimode directional transducer evaluationen_US
dc.typeThesisen_US
dc.contributor.departmentEngineering Acoustics
dc.description.serviceLieutenant Commander, Brazilian Navyen_US
etd.thesisdegree.nameM.S. in Engineering Acousticsen_US
etd.thesisdegree.levelMastersen_US
etd.thesisdegree.disciplineEngineering Acousticsen_US
etd.thesisdegree.grantorNaval Postgraduate Schoolen_US
etd.verifiednoen_US
dc.description.distributionstatementApproved for public release; distribution is unlimited.


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