Passive source localization with a horizontal line array in the shadow zone of the deep water

Area of Science:

• Underwater acoustics
• Array signal processing
• Geophysical exploration

Background:

• Passive source localization is crucial in underwater acoustics.
• Vertical line arrays are commonly used, but horizontal line arrays (HLAs) are less explored for deep-water localization.
• HLAs are widely deployed in deep-water operations, necessitating effective localization methods.

Purpose of the Study:

• To develop and validate a broadband source localization method using HLAs in deep-water shadow zones.
• To estimate both the range and depth of underwater sound sources.
• To improve computational efficiency and robustness compared to existing methods.

Main Methods:

• A novel localization approach employing a horizontal line array (HLA) in deep-water shadow zones.
• Matching measured time delays from multipath arrivals against a precomputed replica library.
• Time delays extracted from beamformed acoustic intensity steered toward the estimated source direction.
• Validation using numerical simulations and experimental data from the South China Sea.

Main Results:

• The proposed method effectively estimates source range and depth using HLAs.
• Demonstrated significant reduction in computational complexity compared to the matched-interference-structure method.
• Showcased enhanced robustness against environmental uncertainties, including sound speed profile and water depth variations.

Conclusions:

• The developed broadband source localization method using HLAs is effective in deep-water environments.
• The technique offers a computationally efficient and robust alternative for passive source localization.
• This research contributes to advancing underwater acoustic localization capabilities with widely deployed HLAs.