High-performance towing cable hydrophone array with an improved ultra-sensitive fiber-optic distributed acoustic...

Area of Science:

• Oceanography
• Acoustics
• Sensor Technology

Background:

• Traditional hydrophone arrays face limitations in sensitivity and weight for towing applications.
• Fiber-optic distributed acoustic sensing (DAS) offers potential for enhanced underwater acoustic monitoring.

Purpose of the Study:

• To demonstrate and test a high-performance towing cable hydrophone array utilizing an improved ultra-sensitive fiber-optic distributed acoustic sensing (uDAS) system.
• To evaluate the array's performance in terms of sensitivity, noise floor, and remote target localization capabilities.

Main Methods:

• Development and optimization of a new composite transducer to improve acoustic pressure sensitivity.
• Sea trial testing of the uDAS hydrophone array, assessing flow noise, signal capture, beamforming, and localization.
• Utilizing picostrain sensitivity for enhanced acoustic detection.

Main Results:

• Achieved an average sensitivity of -129.23 dB re rad/µPa across a frequency range of 10 Hz to 1500 Hz.
• Successfully localized artificial acoustic sources at distances of 5 km and 10 km.
• Demonstrated high sensitivity and a low noise floor in the hydrophone array.

Conclusions:

• The developed uDAS towing cable hydrophone array exhibits excellent performance, including high sensitivity and remote target localization.
• The system's simple structure and capabilities suggest potential for next-generation lightweight hydrophone arrays for towing applications.
• This technology paves the way for advancements in underwater acoustic detection and monitoring systems.