A Vertical Array Of Directional Acoustic Sensors

Nickles, J. C.; Edmonds, G. L.; Harriss, R.A.; Fisher, F. H.; Hodgkiss, William S.; Giles, John W.; D’Spain, Gerald L.

doi:10.1109/oceans.1992.612714

Cited by 47 publications

(23 citation statements)

References 3 publications

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“…Vector gradient arrays of hydrophones have been used in the past for underwater direction-finding by Nickles et al ͑1992͒ andTichavsky et al ͑2001͒. However, the successful application of aeroacoustic vector gradient arrays for highresolution direction-finding has not been reported to our knowledge, except in our initial studies ͑Mohan et al, 2003a,b͒.…”

Section: Resultsmentioning

confidence: 92%

Localization of multiple acoustic sources with small arrays using a coherence test

Mohan

Lockwood

Kramer

et al. 2008

The Journal of the Acoustical Society of America

106

108

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Direction finding of more sources than sensors is appealing in situations with small sensor arrays. Potential applications include surveillance, teleconferencing, and auditory scene analysis for hearing aids. A new technique for time-frequency-sparse sources, such as speech and vehicle sounds, uses a coherence test to identify low-rank time-frequency bins. These low-rank bins are processed in one of two ways: (1) narrowband spatial spectrum estimation at each bin followed by summation of directional spectra across time and frequency or (2) clustering low-rank covariance matrices, averaging covariance matrices within clusters, and narrowband spatial spectrum estimation of each cluster. Experimental results with omnidirectional microphones and colocated directional microphones demonstrate the algorithm's ability to localize 3-5 simultaneous speech sources over 4 s with 2-3 microphones to less than 1 degree of error, and the ability to localize simultaneously two moving military vehicles and small arms gunfire.

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Section: Resultsmentioning

confidence: 92%

Localization of multiple acoustic sources with small arrays using a coherence test

Mohan

Lockwood

Kramer

et al. 2008

The Journal of the Acoustical Society of America

106

108

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“…Many different types of velocity hydrophones are available [2] and have been constructed using a variety of technologies, with designs ranging from mechanically based [4], to optically based [6], to derivative-based [16]. One implementation of the vector hydrophone is the DIFAR sensor [11], [12].…”

mentioning

confidence: 99%

Extended-aperture underwater acoustic multisource azimuth/elevation direction-finding using uniformly but sparsely spaced vector hydrophones

Wong

Zoltowski

1997

IEEE J. Oceanic Eng.

129

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Abstract-Aperture extension is achieved in this novel ESPRITbased two-dimensional angle estimation scheme using a uniform rectangular array of vector hydrophones spaced much farther apart than a half-wavelength. A vector hydrophone comprises two or three spatially co-located, orthogonally oriented identical velocity hydrophones (each of which measures one Cartesian component of the underwater acoustical particle velocity vector-field) plus an optional pressure hydrophone. Each incident source's directions-of-arrival are determined from the source's acoustical particle velocity components, which are extracted by decoupling the data covariance matrix's signal-subspace eigenvectors using the lower dimensional eigenvectors obtainable by ESPRIT. These direction-cosine estimates are unambiguous but have high variance; they are used as coarse references to disambiguate the cyclic phase ambiguities in ESPRIT's eigenvalues when the intervector-hydrophone spacing exceeds a halfwavelength. In one simulation scenario, the estimation standard deviation decreases with increasing intervector-hydrophone spacing up to 12 wavelengths, effecting a 97% reduction in the estimation standard deviation relative to the half-wavelength case. This proposed scheme and the attendant vector-hydrophone array outperform a uniform half-wavelength spaced pressurehydrophone array with the same aperture and slightly greater number of component hydrophones by an order of magnitude in estimation standard deviation. Other simulations demonstrate how this proposed method improves underwater acoustic communications link performance. The virtual array interpolation technique would allow this proposed algorithm to be used with irregular array geometries.

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“…, e K ] denotes a perturbation matrix of eigenvectors in signal subspace, and it is assumed that the perturbation on matrix T is not considered. Since 8 the perturbation on the steering vector a 1 k is given by Thus, the covariance matrix of a u k is given by …”

Section: The Covariance Of the Steering Vector Estimate Errormentioning

confidence: 99%

“…A standard DIFAR (DIrectional Frequency Analysis and Recording) sensor [8] consists of only two velocity-hydrophones, in X and Y axis, and one pressurehydrophone. Thus, the standard DIFAR sensor produces a 3×…”

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confidence: 99%

Direction-finding of coherent signals based on cylindrical vector-hydrophones array

Tao

Chang

Cui

2009

SIViP

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In this paper, a new "particle-velocity-field and spatial smoothing" (PVFSS) algorithm is proposed for direction-finding of coherent signals, using the cylindrical vector-hydrophones array in the underwater acoustic medium. In contrast to the customary "spatial smoothing" technique, it provides a smaller reduction in the overall array's spatial aperture. While in contrast to the "particlevelocity-field smoothing" technique, it may increase the number of decorrelate-able coherent signals. Moreover, an ESPRIT-based, closed-form direction-finding algorithm is proposed and a method of removing cyclic ambiguity is provided. Finally, the theoretical performance of the proposed algorithm is analyzed. Simulation results are shown to verify the efficacy of the proposed algorithm.

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A Vertical Array Of Directional Acoustic Sensors

Cited by 47 publications

References 3 publications

Localization of multiple acoustic sources with small arrays using a coherence test

Localization of multiple acoustic sources with small arrays using a coherence test

Extended-aperture underwater acoustic multisource azimuth/elevation direction-finding using uniformly but sparsely spaced vector hydrophones

Direction-finding of coherent signals based on cylindrical vector-hydrophones array

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