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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
Observations of low-frequency temporal and spatial coherence in shallow water
1Division of Applied Marine Physics, RSMAS-University of Miami, Miami, Florida 33149, USA. hdeferrari@rsmas.miami.edu
The Journal of the Acoustical Society of America
|January 29, 2009
Summary
Multipath interference complicates coherence measurements. This study separates signals to accurately compute temporal and spatial coherence, finding lower-order surface/bottom reflected modes are more coherent.
Area of Science:
- Acoustics
- Oceanography
- Signal Processing
Background:
- Multipath interference commonly confounds measurements of temporal and spatial coherence.
- Accurate coherence assessment is crucial for understanding wave propagation in complex environments.
Purpose of the Study:
- To develop a method for separating individual propagating modes to enable unambiguous coherence computations.
- To investigate the coherence properties of different acoustic modes, specifically surface reflected bottom reflected (SRBR) versus refracted bottom reflected modes.
Main Methods:
- Utilized two datasets to separate arrivals from individual propagating modes.
- Performed unambiguous computations of temporal and spatial coherence, mitigating multipath effects.
Main Results:
- Lower-order surface reflected bottom reflected (SRBR) modes consistently exhibit higher temporal and spatial coherence than higher-order modes.
- SRBR paths demonstrate significantly greater coherence compared to refracted bottom reflected mode groups.
Conclusions:
- The developed method effectively removes multipath interference for accurate coherence analysis.
- Mode order is a critical factor influencing acoustic coherence, with lower-order modes being more coherent.
- Distinct coherence characteristics exist between SRBR and refracted bottom reflected modes.
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