Show simple item record

dc.contributor.advisorKapolka, Daphne
dc.contributor.authorKok, Chuen Wah
dc.dateDec-12
dc.date.accessioned2013-02-15T23:13:45Z
dc.date.available2013-02-15T23:13:45Z
dc.date.issued2012-12
dc.identifier.urihttp://hdl.handle.net/10945/27855
dc.descriptionApproved for public release; distribution is unlimited.en_US
dc.description.abstractThe advent of particle velocity sensors as a viable addition to traditional pressure-based sensors in acoustics has fueled considerable research into the additional capabilities they might bring. Previous thesis work performed at NPS successfully demonstrated a working acoustic beamformer using a hybrid array comprised of a single conventional omnidirectional microphone and two 3D Microflown Ultimate Sound Probes in an anechoic chamber. These Microflown sensors are vector sensors. They have integrated directionality through the inclusion of three orthogonal particle velocity sensors with a microphone. Unfortunately, the signals of the particle velocity sensors obtained outside in a light, gusting wind were unusable due to broadband noise. Since the fundamental limit to detecting quiet targets depends on the noise floor, the aim of this thesis was to perform an in situ measurement of the pressure equivalent noise floor of all sensors in the array and to minimize the wind noise. Noise levels measured in an anechoic chamber were 915 dB higher than the levels expected from the sensors alone. The additional noise is attributed to the data acquisition equipment. The use of an ACO WS7 windscreen was shown to be extremely effective in mitigating broadband wind noise.en_US
dc.publisherMonterey, California. Naval Postgraduate Schoolen_US
dc.titleDetermination of the pressure equivalent noise signal of vector sensors in a hybrid arrayen_US
dc.typeThesisen_US
dc.contributor.secondreaderSmith, Kevin B.
dc.contributor.departmentPhysics
dc.subject.authorParticle Velocityen_US
dc.subject.authorAcoustic Arrayen_US
dc.subject.authorAcoustic Vector Sensoren_US
dc.subject.authorMicroflownen_US
dc.subject.authorHybrid Arrayen_US
dc.subject.authorDirectionalen_US
dc.subject.authorPressure Equivalent Noise Floor.en_US
dc.description.serviceME5, Republic of Singapore Navyen_US
etd.thesisdegree.nameMaster of Science In Combat Systems Technologyen_US
etd.thesisdegree.levelMastersen_US
etd.thesisdegree.disciplineCombat Systems Technologyen_US


Files in this item

Thumbnail

This item appears in the following Collection(s)

Show simple item record