Sources depth estimation for a tonal source by matching the interference structure in the arrival angle domain.

Area of Science:

• Underwater acoustics
• Acoustic signal processing
• Oceanography

Background:

• Passive source depth estimation using Vertical Line Arrays (VLA) relies on acoustic arrival angle interference patterns.
• Existing methods using isovelocity approximations fail at longer ranges due to ignored sound speed profile effects.

Purpose of the Study:

• To develop an improved passive source depth estimation method for moving tonal sources.
• To incorporate sound speed profile information for enhanced accuracy, especially at greater ranges.

Main Methods:

• Developed a theoretical formula to model interference structures in the arrival angle domain, considering the sound speed profile.
• Matched measured interference patterns from VLA beamforming with modeled structures to estimate source depth.

Main Results:

• Successfully estimated source depths for both simulated and experimental data, including towed and passing ship sources.
• Demonstrated improved depth estimation accuracy for sources at remote ranges compared to previous methods.

Conclusions:

• The proposed method effectively estimates the depth of moving tonal sources, even at extended ranges.
• Accounting for the sound speed profile is crucial for accurate passive acoustic source localization in underwater environments.