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Measurement of the Directional Information Flow in fNIRS-Hyperscanning Data using the Partial Wavelet Transform Coherence Method
Published on: September 3, 2021
A model for spatial coherence from directive ambient noise in attenuating, dispersive media
1Marine Physical Laboratory of the Scripps Institution of Oceanography, University of California San Diego, La Jolla, California 92093-0238, USA. scwalker@ucsd.edu
The Journal of the Acoustical Society of America
|July 12, 2012
Summary
This study presents exact formulas for analyzing diffuse sound waves, aiding in understanding underwater environments using ambient noise. These models help infer geo-acoustic properties from wave field coherence.
Area of Science:
- Geophysics and Acoustics
- Oceanography
- Wave Propagation
Background:
- Inferring geo-acoustic properties from ambient noise is crucial for underwater exploration.
- Experimental efforts require complementary theoretical models for validation and broader application.
- Understanding the behavior of diffuse random wave fields is key to accurate environmental characterization.
Purpose of the Study:
- To derive exact, explicit, closed-form expressions for the cross-spectral density and spatial coherence of diffuse random wave fields.
- To provide a theoretical framework that complements experimental seismics and acoustics.
- To facilitate the modeling of broadband wave coherence in complex underwater environments.
Main Methods:
- Development of analytical expressions for wave field statistics.
- Focus on second-order statistics of ambient noise.
- Formulation for dispersive and attenuating media.
Main Results:
- Exact, explicit, closed-form expressions for cross-spectral density and spatial coherence.
- Demonstration of suitability for modeling broadband, diffuse wave coherence.
- Inclusion of directive ambient noise from local and distant sources.
Conclusions:
- The derived expressions offer a robust theoretical tool for analyzing ambient noise in underwater acoustics.
- These models enhance the interpretation of geo-acoustic properties derived from wave field measurements.
- The work supports advancements in underwater sensing and environmental characterization through improved wave propagation modeling.
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