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Extension of DAMAS Phased Array Processing for Spatial Coherence Determination (DAMAS-C)The present study reports a new development of the DAMAS microphone phased array processing methodology that allows the determination and separation of coherent and incoherent noise source distributions. In 2004, a Deconvolution Approach for the Mapping of Acoustic Sources (DAMAS) was developed which decoupled the array design and processing influence from the noise being measured, using a simple and robust algorithm. In 2005, three-dimensional applications of DAMAS were examined. DAMAS has been shown to render an unambiguous quantitative determination of acoustic source position and strength. However, an underlying premise of DAMAS, as well as that of classical array beamforming methodology, is that the noise regions under study are distributions of statistically independent sources. The present development, called DAMAS-C, extends the basic approach to include coherence definition between noise sources. The solutions incorporate cross-beamforming array measurements over the survey region. While the resulting inverse problem can be large and the iteration solution computationally demanding, it solves problems no other technique can approach. DAMAS-C is validated using noise source simulations and is applied to airframe flap noise test results.
Document ID
20060020679
Document Type
Conference Paper
Authors
Brooks, Thomas F.
(NASA Langley Research Center Hampton, VA, United States)
Humphreys, William M., Jr.
(NASA Langley Research Center Hampton, VA, United States)
Date Acquired
September 7, 2013
Publication Date
January 1, 2006
Subject Category
Acoustics
Report/Patent Number
AIAA Paper 2006-2654
Meeting Information
Meeting: 12th AIAA/CEAS Aeroacoustics Conference
Location: Cambridge, MA
Country: United States
Start Date: May 8, 2006
End Date: May 10, 2006
Sponsors: American Inst. of Aeronautics and Astronautics, National Oceanic and Atmospheric Administraion
Funding Number(s)
OTHER: 23-781-10-09
Distribution Limits
Public
Copyright
Work of the US Gov. Public Use Permitted.
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