Document Detail


Methods for determining infrasound phase velocity direction with an array of line sensors.
MedLine Citation:
PMID:  19062850     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
Infrasound arrays typically consist of several microbarometers separated by distances that provide predictable signal time separations, forming the basis for processing techniques that estimate the phase velocity direction. The directional resolution depends on the noise level and is proportional to the number of these point sensors; additional sensors help attenuate noise and improve direction resolution. An alternative approach is to form an array of directional line sensors, each of which emulates a line of many microphones that instantaneously integrate pressure change. The instrument response is a function of the orientation of the line with respect to the signal wavefront. Real data recorded at the Piñon Flat Observatory in southern California and synthetic data show that this spectral property can be exploited with multiple line sensors to determine the phase velocity direction with a precision comparable to a larger aperture array of microbarometers. Three types of instrument-response-dependent beamforming and an array deconvolution technique are evaluated. The results imply that an array of five radial line sensors, with equal azimuthal separation and an aperture that depends on the frequency band of interest, provides directional resolution while requiring less space compared to an equally effective array of five microbarometers with rosette wind filters.
Authors:
Kristoffer T Walker; Mark A Zumberge; Michael A H Hedlin; Peter M Shearer
Publication Detail:
Type:  Journal Article    
Journal Detail:
Title:  The Journal of the Acoustical Society of America     Volume:  124     ISSN:  1520-8524     ISO Abbreviation:  J. Acoust. Soc. Am.     Publication Date:  2008 Oct 
Date Detail:
Created Date:  2008-12-09     Completed Date:  2009-03-05     Revised Date:  -    
Medline Journal Info:
Nlm Unique ID:  7503051     Medline TA:  J Acoust Soc Am     Country:  United States    
Other Details:
Languages:  eng     Pagination:  2090-9     Citation Subset:  IM    
Affiliation:
Institute of Geophysics and Planetary Physics, Scripps Institution of Oceanography, University of California, San Diego, 9500 Gilman Drive, MC 0225, La Jolla, California 92093-0225, USA.
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MeSH Terms
Descriptor/Qualifier:
Acoustics / instrumentation*
Algorithms
Computer Simulation
Equipment Design
Interferometry
Models, Theoretical
Motion
Noise
Pressure
Signal Processing, Computer-Assisted
Sound*
Time Factors
Wind

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