Processing techniques for circular sonar arrays

Griffiths, HD; Griffiths, J.W.R.; Cowan, C.F.N.; Eiges, R.; Rafik, T.A.

doi:10.1049/cp:19940577

Cited by 6 publications

(6 citation statements)

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“…Our purpose in designing a new beamformer is to have robustness against error defined in (17) in addition to the error mentioned in (10). By the definition of the error er( f ) it is obvious that the errors in matrix T o are due to having inaccurate elements in matrix J or equivalently having errors in the equaliser part of Fig.…”

Section: Proposed Beamformermentioning

confidence: 99%

“…where ΔJ is a diagonal matrix in which the vector of its diagonal elements is equal to er( f ). With these considerations and substituting (10) and (16) into (15), the problem of finding optimum weights is converted to the following problem…”

Section: Proposed Beamformermentioning

confidence: 99%

“…where ε and ε i are defined in (10) and (26), respectively. In addition, it is shown in Appendix 1 that the vector z 3 = ΔTa belongs to the ellipsoid B 3v B 3v 0, P 3v = P 1/2 3v v| v ≤ 1 (29)…”

Section: Proposed Beamformermentioning

confidence: 99%

“…In this technique, the UCA is converted to a virtual uniform linear array (ULA) [7]. Using this transformation, beamforming and DOA estimation methods that need the Vandermode structure of steering vector can be applied to the virtual array [8][9][10][11]. However, this transformation is not ideal and there are some approximations in its formulation.…”

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Robust beamforming in circular arrays using phase‐mode transformation

Askari

Karimi

Atbaee

2013

IET signal process.

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Having many benefits, phase-mode transformation technique is used frequently in beamforming with circular arrays. Owig to the fact that this transformation is frequency dependent, some techniques are used to make this transformation appropriate for broadband applications. When this technique is used with uniform circular arrays, its performance degrades because of the approximations applied to the formulations. In this study, the authors propose a new beamforming method not only robust against uncertainty in the steering vector of the desired signal, but also robust against errors caused by the phase-mode transformation. The authors assume that steering vector of the desired signal pertains to a ball set and ellipsoid sets are considered to cover the transformation matrix columns. The proposed beamforming method is based on semi-definite programming. The performance of the proposed beamforming method is compared with several other beamforming techniques by using a simulation study.

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Section: Proposed Beamformermentioning

confidence: 99%

Section: Proposed Beamformermentioning

confidence: 99%

Section: Proposed Beamformermentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Robust beamforming in circular arrays using phase‐mode transformation

Askari

Karimi

Atbaee

2013

IET signal process.

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“…Even if a small number of sensors uniformly distribute on a uniform circular array, the fluctuation of the array pattern is extremely small [13]. The uniform cylindrical array with the characteristic of the uniform circular array and the uniform linear array have been applied to the source localization [14].…”

mentioning

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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