Open AccessBook
Fourier Acoustics: Sound Radiation and Nearfield Acoustical Holography
Earl G. Williams,J. Adin Mann +1 more
TLDR
The Inverse Problem: Cylindrical NAH. as discussed by the authors The Inverse problem: Planar NAH and the Inverse NP-hardness of planar plane waves.Abstract:
Preface. Fourier Transforms & Special Functions. Plane Waves. The Inverse Problem: Planar NAH. Cylindrical Waves. The Inverse Problem: Cylindrical NAH. Spherical Waves. Spherical NAH. Green Functions & the Helmholtz Integral. Index.read more
Citations
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Journal Article
Real-Time Conversion of Sensor Array Signals into Spherical Harmonic Signals with Applications to Spatially Localized Sub-Band Sound-Field Analysis
TL;DR: In this article, the authors present two real-time audio plug-ins for processing sensor array signals for sound field visualisation, which encode the array signals into spherical harmonic signals and use these intermediate signals to estimate the direction of arrival of sound sources.
Journal ArticleDOI
A Methodology for the Robust Estimation of the Radiation Pattern of Acoustic Sources
TL;DR: A novel methodology for estimating the radiation pattern of acoustic sources, which is general enough as to be suitable for a wide variety of sources without the need of anechoic conditions of operation, is proposed and experimental results confirm a relevant improvement in accuracy and robustness afforded by the adoption of dynamic plenacoustic solutions with respect to state of theart techniques.
Journal ArticleDOI
Direction of arrival estimation in practical scenarios using moving standard deviation processing for localization and tracking with acoustic vector sensors
TL;DR: Utilizing multiple AVS sites, in-air pp AVS are demonstrated to localize sources with complex signatures to estimate direction of arrival (DOA) in real-world environments with various frequency content and signal to noise ratio.
Spatial reproduction of near sources at low frequency using adaptive panning
Dylan Menzies,Filippo Maria Fazi +1 more
TL;DR: In this paper, the panning gains are no longer frequency independent, but can be approximated efficiently using a 1st order filter, which can be used to compensate for the tracked head orientation.
Dissertation
Application of PEA technique to space charge measurement in cylindrical geometry HV cable systems
Abstract: Space charge, as one of the major concerns for the reliability of polymeric High Voltage Direct Current (HVDC) cables, has drawn wide attention in both academia and industry. Accordingly, measurement techniques along with accurate data interpretation have been required to study space charge behaviour in insulation materials and to provide solid bases for simulation activities. In this work, a high temperature space charge measurement system for mini-cables has been developed based on the Pulsed Electro-Acoustic (PEA) method. In parallel, simulation tools for space charge accumulation, based on non-linear unipolar charge transport models, the acoustic signal formation, transmission of acoustic waves, and their detection, have been developed for PEA measurement on mini-cables to provide an alternative way for interpreting the raw experimental data rather than the traditional approaches of reconstructing space charge information by signal processing and calibration. The simulation uses 2-D simulation tools and includes the clamping unit of the PEA cell to provide, for the first time, a detailed comparison of the two commonly used shapes, flat and curved, of the base electrode. Benefiting from the ability of applying isothermal experimental conditions of 20 – 70 °C, the transient of ‘intrinsic’ space charge accumulation due to the field and temperature dependent conductivity has been studied by means of a novel experimental data analysis method proposed in this work. In addition, the analysis provides a way to assess conductivity models by matching the simulation results with the experimental space charge results. By applying the simulation tools, the effect of the possible cable defects of non-concentricity and a mismatch between the insulation and semicon layers could be assessed. Furthermore, the origin of the bulk space charge signal experimentally observed in a mini-cable was found to be consistent with a radius dependent conductivity which may be a consequence of incomplete degassing.
Related Papers (5)
A highly scalable spherical microphone array based on an orthonormal decomposition of the soundfield
Jens Meyer,Gary W. Elko +1 more