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Scattering from extended targets in range-dependent fluctuating ocean-waveguides with clutter from theory and
Srinivasan Jagannathan1, Elizabeth T Küsel, Purnima Ratilal
1Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, USA.
The Journal of the Acoustical Society of America
|August 17, 2012
Summary
Sonar Equation and Ingenito models inaccurately estimate acoustic scattering from underwater targets. Full-field modeling accurately predicts scattered returns, enabling better distinction between man-made objects and natural clutter like fish schools.
Area of Science:
- Ocean acoustics
- Underwater acoustics
- Waveguide scattering
Background:
- Accurate acoustic scattering models are crucial for underwater target detection.
- Traditional models often fail in complex, range-dependent ocean environments.
Purpose of the Study:
- To evaluate the accuracy of existing acoustic scattering models.
- To develop and validate a more robust modeling approach for complex environments.
- To assess the potential for multi-frequency sensing in target discrimination.
Main Methods:
- Conducted bistatic, long-range acoustic scattering measurements.
- Compared field data with Sonar Equation and Ingenito model predictions.
- Employed Green's theorem-based full-field modeling for range-dependent waveguides.
Main Results:
- Sonar Equation and Ingenito models produced significant errors (order of magnitude).
- Full-field modeling accurately described scattered field statistics in field experiments.
- Distinct spectral dependencies observed between man-made targets and fish schools.
Conclusions:
- Existing models are inadequate for fluctuating, range-dependent waveguides.
- Green's theorem-based full-field modeling provides accurate predictions.
- Multi-frequency sensing can differentiate man-made targets from natural clutter.
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