Understanding deep-water striation patterns and predicting the waveguide invariant as a distribution depending on...

Area of Science:

• Underwater acoustics
• Wave propagation modeling
• Geophysical signal processing

Background:

• Waveguide Invariant (WI) theory quantifies intensity interference patterns in underwater acoustics.
• In shallow waters with stratified sound speed, WI varies with source/receiver depth, aiding passive source localization.
• Deep-water acoustic interference patterns are complex and highly variable with range and depth.

Purpose of the Study:

• To investigate the phenomena causing variability in deep-water acoustic interference patterns.
• To develop a new WI distribution derivation integrating mode dominance and frequency-dependent eigenmodes.
• To validate the proposed derivation against synthetic data for deep-water acoustic analysis.

Main Methods:

• Employed a ray-mode approach to model acoustic propagation in deep water.
• Integrated the dominance of acoustic field by groups of modes and frequency dependence of eigenmodes into WI derivation.
• Validated the derived WI distribution against a reference distribution from synthetic acoustic data.

Main Results:

• Identified mode dominance and frequency-dependent eigenmodes as key factors in deep-water WI variability.
• Developed a novel WI distribution derivation that accounts for these deep-water phenomena.
• The derived WI distribution accurately predicts and explains striation patterns in deep-water acoustic fields.

Conclusions:

• The proposed WI derivation offers a robust method for understanding and predicting complex acoustic interference patterns in deep water.
• This approach enhances passive source localization and acoustic analysis in challenging deep-water environments.
• The study validates the importance of considering mode structure and frequency dependence for accurate acoustic modeling.