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Mid-frequency sound propagation through internal waves at short range with synoptic oceanographic observations
The Journal of the Acoustical Society of America
|December 3, 2008
Summary
Nonlinear internal waves alter underwater acoustics. Analysis of acoustic data during the Shallow Water 2006 Experiment revealed a new acoustic path generated by a nonlinear internal wave passing over the acoustic source.
Area of Science:
- Oceanography
- Acoustics
- Wave Physics
Background:
- Underwater acoustic propagation is influenced by environmental factors.
- Nonlinear internal waves (NIWs) are significant oceanographic phenomena.
- Previous studies have not fully explored the acoustic effects of NIWs.
Purpose of the Study:
- To analyze mid-frequency acoustic transmission data.
- To investigate the impact of a nonlinear internal wave on acoustic paths.
- To model the position of an internal wave.
Main Methods:
- Collected acoustic data using a vertical array.
- Utilized oceanographic data for wave modeling.
- Developed a plane-wave model for NIW position.
- Analyzed data collected before, during, and after NIW passage.
Main Results:
- Observed changes in acoustic transmission.
- Identified the generation of a new acoustic path.
- Demonstrated the influence of NIW passage on acoustic signals.
- Validated the plane-wave model with experimental data.
Conclusions:
- Nonlinear internal waves significantly affect underwater acoustic propagation.
- A new acoustic path can be formed by the presence of NIWs.
- The study provides preliminary evidence for acoustic path generation due to NIWs.
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