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Characterization of Diffusive Noise Fields Using Ambient Noise Interferometry,…

Award Information

Department of Defense
Award ID:
Program Year/Program:
2010 / STTR
Agency Tracking Number:
Solicitation Year:
Solicitation Topic Code:
NAVY 10T004
Solicitation Number:
Small Business Information
Rocky Mountain Geophysics, Llc
167 Piedra Loop Los Alamos, NM 87544-3836
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Woman-Owned: No
Minority-Owned: No
HUBZone-Owned: No
Phase 1
Fiscal Year: 2010
Title: Characterization of Diffusive Noise Fields Using Ambient Noise Interferometry, Spatial Gradients and Acoustic Bright Spots
Agency / Branch: DOD / NAVY
Contract: N68335-10-C-0432
Award Amount: $70,000.00


We propose to conduct a feasibility study for utilizing broadband sampling of the diffusive noise field in a dynamic environment. In ambient noise studies, the ability to resolve a wavefield is proportional to its time-bandwidth (TB) product. In a dynamic environment such as in the atmosphere or ocean, the nature of the impinging wave field is changing rapidly so that only short time segments can be used to model the ambient wave field thereby reducing the TB product. One way to counter the effect of a reduced time window is to increase the bandwidth of measurement. Our approach is to broaden the frequency spectrum used to characterize diffusive noise fields in dynamic environments by addition of Intensity Level Differences (ILD) caused by diffraction around a shadowing object to the more commonly used interferometric phase delay methods. Diffraction around a shadowing object can create acoustic bright spots that are easily detected. As an experimental test, we will use ambient noise data from existing infrasonic arrays and characterize the dynamic wavefield using passive interferometry and spatial gradiometry techniques. For spatial gradient techniques, the required sensor footprint is smaller and the wavefield can be mapped at higher resolution at closer ranges.

Principal Investigator:

Steven Taylor

Business Contact:

Steven Taylor
Small Business Information at Submission:

Rocky Mountain Geophysics, Inc.
167 Piedra Loop Los Alamos, NM 87544

EIN/Tax ID: 262641778
Number of Employees:
Woman-Owned: No
Minority-Owned: No
HUBZone-Owned: No
Research Institution Information:
University of California, San Diego
Marine Physical Laboratory, Sc
University of California
San Diego, CA 92093
Contact: Peter Gerstoft
Contact Phone: 8585347768