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Geoacoustic inversion of ambient noise: a simple method
1SACLANT Undersea Research Centre, La Spezia, Italy. harrison@saclantc.nato.int
The Journal of the Acoustical Society of America
|October 26, 2002
Summary
Ambient noise directionality reveals seabed properties. This method uses vertical array measurements to infer geoacoustic parameters from noise reflections, simplifying inversion processes.
Area of Science:
- Oceanography
- Acoustics
- Geophysics
Background:
- Vertical directionality of ambient noise is significantly affected by seabed reflections.
- Understanding seabed properties is crucial for various oceanographic and acoustic applications.
Purpose of the Study:
- To demonstrate a novel method for inferring geoacoustic parameters using ambient noise.
- To validate the feasibility of using noise reflection properties for seabed characterization.
Main Methods:
- Utilizing vertical array measurements to compare upward- and downward-going ambient noise.
- Calculating the power reflection coefficient directly from the noise ratio.
- Minimizing the need for complex modeling and detailed source distribution knowledge.
Main Results:
- Experimental data from five sites (Mediterranean and New Jersey Shelf) were analyzed.
- Consistent reflection properties were observed across different Mediterranean sites despite temporal noise variations.
- The method proved feasible for characterizing seabed reflection properties.
Conclusions:
- The proposed method offers a simplified approach to geoacoustic inversion using ambient noise.
- This technique has potential for characterizing stratified and range-dependent environments.
- Further research can focus on automatic search techniques for geoacoustic parameter estimation.
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