Depth for Underwater Acoustic Detection in Deep-Sea (>5000 m) Complex Marine Environments Based on the Bellhop Model

Area of Science:

• Acoustics and Oceanography
• Underwater Remote Sensing
• Marine Engineering

Background:

• Buoy-based sonar efficiency and deployment optimization are challenging in complex marine environments.
• Existing acoustic models often rely on idealized conditions, limiting applicability in deep-sea settings.

Purpose of the Study:

• To enhance underwater remote sensing data quality through transceiver depth optimization.
• To validate acoustic reciprocity in deep-sea environments (>5000 m) and develop a novel transmission loss model.
• To establish quantitative deployment criteria for deep-sea acoustic detection networks.

Main Methods:

• Utilized the Bellhop ray model for transceiver depth optimization.
• Validated acoustic reciprocity in deep-sea environments with complex sound speed profiles and terrain.
• Developed an equivalent, superposition modeling framework for bidirectional transmission loss (TL).

Main Results:

• Acoustic reciprocity was validated in deep-sea environments with <1.2% relative error.
• A depth-layered dependency mechanism was uncovered, with critical depth difference thresholds identified.
• A performance degradation cliff was observed at ~185m depth difference, reducing detection range by 50%.

Conclusions:

• Defined an optimal detection depth window of 160-350 m and a 150 m transceiver depth difference threshold for mid-layer operations.
• Proposed a layered deployment protocol for deep-sea acoustic detection networks.
• Provided quantitative engineering criteria for designing reliable underwater remote sensing systems.