Matched-field replica model optimization and bottom property inversion in shallow water

Area of Science:

• Ocean acoustics
• Geophysical signal processing
• Shallow-water acoustic propagation

Background:

• Inaccurate geoacoustic parameters in matched-field models lead to incorrect mode predictions.
• This impacts the ambiguity surface and source localization accuracy in shallow-water channels.

Purpose of the Study:

• To reduce degradation in matched-field ambiguity surfaces.
• To obtain optimal replica models for improved source localization.
• To validate improved models with experimental data.

Main Methods:

• Modal-sum-limit optimization
• Bottom-property inversion using multi-tone source-tow data.
• Comparison with nonoptimized models using SWellEX-1 data.

Main Results:

• Optimized models significantly increased matched-field correlation levels.
• Source localization accuracy improved compared to nonoptimized models.
• Predicted number of propagating modes was substantially reduced.

Conclusions:

• Optimized replica models enhance accuracy in shallow-water acoustic propagation studies.
• Inversion for bottom properties yields reliable sediment attenuation estimates.
• Validated techniques improve understanding of acoustic mode behavior.