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IEEE/OES China Ocean Acoustics, 2021
In order to get a deeper research on the underwater acoustic transducer array and obtain the radiation impedance quickly and accurately, a measurement method based on near-field acoustic holography (NAH) for impedance characteristics of underwater ...
Yan Xiao +6 more
semanticscholar +1 more source
In order to get a deeper research on the underwater acoustic transducer array and obtain the radiation impedance quickly and accurately, a measurement method based on near-field acoustic holography (NAH) for impedance characteristics of underwater ...
Yan Xiao +6 more
semanticscholar +1 more source
Near field acoustic holography with microphones on a rigid sphere (L)
The Journal of the Acoustical Society of America, 2011Spherical near field acoustic holography (spherical NAH) is a technique that makes it possible to reconstruct the sound field inside and just outside a spherical surface on which the sound pressure is measured with an array of microphones. This is potentially very useful for source identification. The sphere can be acoustically transparent or it can be
Finn, Jacobsen +3 more
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Journal of the Acoustical Society of America
Near-field acoustic holography (NAH) reconstructs complex acoustic pressure fields from near-field microphone measurements. The equivalent source method (ESM), which relies on least squares inversion, is highly susceptible to measurement outliers.
William R. Lippincott +3 more
semanticscholar +1 more source
Near-field acoustic holography (NAH) reconstructs complex acoustic pressure fields from near-field microphone measurements. The equivalent source method (ESM), which relies on least squares inversion, is highly susceptible to measurement outliers.
William R. Lippincott +3 more
semanticscholar +1 more source
A one-step patch near-field acoustical holography procedure
The Journal of the Acoustical Society of America, 2007When performing holography measurements over a limited area of a source, the hologram pressure typically remains finite at the edge of the measurement aperture. Patch near-field acoustical holography (NAH) has been developed specifically to mitigate the effects related to that windowing.
Moohyung, Lee, J Stuart, Bolton
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THEORY AND BOUNDARY ELEMENT METHODS FOR NEAR-FIELD ACOUSTIC HOLOGRAPHY
Journal of Computational Acoustics, 2005We consider the problem of recovering surface vibrations from acoustic pressure measurements taken in the interior or the exterior of a region. We give two formulations of the problem. One is based on a representation of the pressure as layer potentials and the other is based on approximation by a class of specific solutions to the Helmholtz equation.
Delillo, Thomas +2 more
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Near-field acoustical holography—interior problems
The Journal of the Acoustical Society of America, 1997Near-field acoustical holography (NAH) provides a practical solution to a challenging inverse problem: Calculation of the normal velocity on the surface of a vibrator from the pressure field measured in the acoustic near field of the vibrating surface.
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A boundary element method based near field acoustic holography in noisy environments.
Journal of the Acoustical Society of America, 2020In noisy environments, the acoustic wave is complicated and consists of the radiated wave, the incident wave, as well as its scattering wave. Double-layered pressure measurement is introduced to the boundary element method based near field acoustic ...
Hai-Jun Wu +3 more
semanticscholar +1 more source
A comparison of SONAH and IBEM for near-field acoustic holography
The Journal of the Acoustical Society of America, 2008Among the popular techniques for acoustic source identification in complex environments are the Statistically Optimal Near Acoustic Holography (SONAH) and the Inverse Boundary Element Method (IBEM). These two methods are quite different regarding the underlying assumptions and the practical implementations: Whereas SONAH performs the back-propagation ...
Peter Juhl, Jesper Gomes
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Near-field acoustical holography in enclosed spaces
The Journal of the Acoustical Society of America, 2003In enclosed spaces, the locations of surfaces from which most of the noise radiation occurs can be difficult to determine in the presence of reverberation and contributions from other sources. By using microphones configured in an array that confirms to the surface of interest, it should be possible to map the acoustic field inside the enclosed space ...
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Applications of Near-field Acoustic Holography on Small Apertures
The Journal of the Acoustical Society of America, 2008Small, finite measurement apertures are a major impediment for accurate and fast application of near-field acoustic holography (NAH). In theory, FFT-based NAH methods are very powerful and acquire extremely fast inverse calculations of the sound field.
Rick Scholte +3 more
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