Line-array beamforming using linear prediction for aperture interpolation and extrapolation

Swingler, D.N.; Walker, Roger

doi:10.1109/29.17497

Cited by 81 publications

(47 citation statements)

References 15 publications

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“…Diverse approaches have been advanced to extend array aperture with a sparse array: 1) Swingler and Walker [7] model impinging signals as ARMA time series, estimate the ARMA coefficients from the data correlation matrix, and then use linear prediction to extrapolate actual data collected at actual array elements for virtual array elements located outside the physical array aperture; 2) Shiue et al [9], Tufts et al [18], and Wong and Zoltowski [24], [25] construct arrays with two or more sizes of intersensor spacing between adjacent array elements; and 3) Dogan and Mendel [19] use higher order statistics, which require long observation times and exceedingly intensive computation. The novel algorithm introduced in this paper embodies a fourth approach, recognizing the vectorfield nature of the impinging underwater acoustical wavefield and thus exploiting the arrival angle information embedded in individual Cartesian components of the impinging particle velocity vector-field.…”

Section: B Summary Of Relevant Literaturementioning

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.

130

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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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Section: B Summary Of Relevant Literaturementioning

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.

130

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“…However, the rst approach only estimates the power spectrum and ignores the phase spectrum. The second approach, despite being more computationintensive, produces both the power and phase spectra and this is sometimes useful for radar and sonar applications (Swingler andWalker 1989, Wu 1995). Moreover this data extrapolation approach is insensitive to the order of model.…”

Section: Super-resolution Processingmentioning

confidence: 99%

Three-dimensional space-borne synthetic aperture radar (SAR) imaging with multiple pass processing

She¹,

Gray²,

Bogner³

et al. 2002

International Journal of Remote Sensing

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Three-dimensional (3D) synthetic aperture radar (SAR) imaging via multiple-pass processing is an extension of interferometric SAR imaging. It exploits more than two flight passes to achieve a desired resolution in elevation. In this paper, a novel approach is developed to reconstruct a 3D space-borne SAR image with multiple-pass processing. It involves image registration, phase correction and elevational imaging. An image model matching is developed for multiple image registration, an eigenvector method is proposed for the phase correction and the elevational imaging is conducted using a Fourier transform or a super-resolution method for enhancement of elevational resolution. 3D SAR images are obtained by processing simulated data and real data from the first European Remote Sensing satellite (ERS-1) with the proposed approaches. Abstract. Three-dimensional (3D) synthetic aperture radar (SAR) imaging via multiple-pass processing is an extension of interferometric SAR imaging. It exploits more than two ight passes to achieve a desired resolution in elevation. In this paper, a novel approach is developed to reconstruct a 3D space-borne SAR image with multiple-pass processing. It involves image registration, phase correction and elevational imaging. An image model matching is developed for multiple image registration, an eigenvector method is proposed for the phase correction and the elevational imaging is conducted using a Fourier transform or a super-resolution method for enhancement of elevational resolution. 3D SAR images are obtained by processing simulated data and real data from the rst European Remote Sensing satellite (ERS-1) with the proposed approaches.

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“…12 Investigations have also included extrapolating an array to a larger aperture, allowing greater resolution. 10 These techniques do not attempt to give meaningful results above the spatial Nyquist frequency, f N , as accurate interpolation requires the array element spacing to be less than half a wavelength. 10 The most promising technique to date for increasing the bandwidth of a beamforming array involves carefully designed non-uniform microphone spacing patterns; even this technique only allows beamforming up to about 6 f N of the average spacing, 13 and does so at the cost of a significant decrease in SNR.…”

Section: Introductionmentioning

confidence: 99%

“…10 These techniques do not attempt to give meaningful results above the spatial Nyquist frequency, f N , as accurate interpolation requires the array element spacing to be less than half a wavelength. 10 The most promising technique to date for increasing the bandwidth of a beamforming array involves carefully designed non-uniform microphone spacing patterns; even this technique only allows beamforming up to about 6 f N of the average spacing, 13 and does so at the cost of a significant decrease in SNR. 14 An essential element of our proposed method to extend the bandwidth above f N is phase unwrapping, which is the process of computing the absolute phase difference between signals from the ½Àp; p limited argument of the cross spectrum.…”

Section: Introductionmentioning

confidence: 99%

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Extending the bandwidth of an acoustic beamforming array using phase unwrapping and array interpolation

Goates

Harker

Neilsen

et al. 2017

The Journal of the Acoustical Society of America

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A method is presented to suppress grating lobes in beamforming using phase unwrapping and array interpolation. When the phase of each cross spectrum is successfully unwrapped, the magnitude and phase of the cross spectral matrix may be interpolated; for cases where these quantities vary smoothly, interpolation is straightforward, even above the spatial Nyquist frequency. Two applications are presented: localization of a broadband source and characterization of a source with frequency-dependent location. In both cases, grating lobes are suppressed and the source is localized at frequencies up to at least 8 times the spatial Nyquist frequency.

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Line-array beamforming using linear prediction for aperture interpolation and extrapolation

Cited by 81 publications

References 15 publications

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

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

Three-dimensional space-borne synthetic aperture radar (SAR) imaging with multiple pass processing

Extending the bandwidth of an acoustic beamforming array using phase unwrapping and array interpolation

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