Truncated aperture extrapolation for Fourier-based near-field acoustic holography by means of border-padding
2009 (English)In: Journal of the Acoustical Society of America, ISSN 0001-4966, E-ISSN 1520-8524, Vol. 125, no 6, 3844-3854 p.Article in journal (Refereed) Published
Although near-field acoustic holography (NAH) is recognized as a powerful and extremely fast acoustic imaging method based on the inverse solution of the wave-equation, its practical implementation has suffered from problems with the use of the discrete Fourier transformation (DFT) in combination with small aperture sizes and windowing. In this paper, a method is presented that extrapolates the finite spatial aperture before the DFT is applied, which is based on the impulse response information of the known aperture data. The developed method called linear predictive border-padding is an aperture extrapolation technique that greatly reduces leakage and spatial truncation errors in planar NAH (PNAH). Numerical simulations and actual measurements on a hard-disk drive and a cooling fan illustrate the low error, high speed, and utilization of border-padding. Border-padding is an aperture extrapolation technique that makes PNAH a practical and accurate inverse near-field acoustic imaging method.
Place, publisher, year, edition, pages
2009. Vol. 125, no 6, 3844-3854 p.
Discrete fourier transformation, Extrapolation techniques, Fourier, Hard Disk Drive, Imaging method, Inverse solution, Near-field acoustics, Nearfield Acoustic Holography, Numerical simulation, Practical implementation, Small aperture, Truncation errors, Acoustic holography, Acoustics, Approximation theory, Discrete Fourier transforms, Extrapolation, Fourier analysis, Holographic interferometry, Imaging systems, Impulse response, Interferometry, Inverse problems, Probability density function, Acoustic imaging, accuracy, article, Fourier transformation, frequency modulation, holography, imaging, mathematical analysis, measurement, noise measurement, prediction, priority journal, quantum mechanics, simulation, sound detection, spectroscopy, waveform
Fluid Mechanics and Acoustics
IdentifiersURN: urn:nbn:se:kth:diva-66757DOI: 10.1121/1.3126994ISI: 000266667400043OAI: oai:DiVA.org:kth-66757DiVA: diva2:498955
QC 201202132012-02-122012-01-272012-02-13Bibliographically approved