Development and Testing of a Dual Accelerometer Vector Sensor for AUV Acoustic Surveys

Area of Science:

• Oceanography
• Acoustics
• Robotics

Background:

• Geophysical acoustic surveys at sea are crucial for understanding underwater environments.
• Current methods using Autonomous Underwater Vehicles (AUVs) can be improved for efficiency and data processing.
• Traditional towed arrays present limitations in maneuverability and integration with AUVs.

Purpose of the Study:

• To design, manufacture, and test a novel Dual Accelerometer Vector Sensor (DAVS).
• To assess the DAVS's capability to enhance geophysical acoustic surveys conducted by AUVs.
• To demonstrate the spatial filtering capabilities of the DAVS for improved data acquisition.

Main Methods:

• The DAVS was designed and manufactured as a compact unit integrating two tri-axial accelerometers and one hydrophone.
• Sensor sensitivity and directionality were calibrated in a controlled tank environment.
• Acoustic wave azimuth estimation capabilities were evaluated using the DAVS mounted on a Medusa Class AUV around a sound source.

Main Results:

• The DAVS demonstrated potential for spatial filtering, enabling discrimination between surface and bottom reflections.
• The compact design facilitates easier integration with AUVs, enhancing maneuverability.
• Successful acoustic wave azimuth estimation was achieved, validating the sensor's directional capabilities.

Conclusions:

• The Dual Accelerometer Vector Sensor (DAVS) offers a promising solution for improving the efficiency of marine geophysical acoustic surveys.
• Its spatial filtering and compact design contribute to reduced post-processing and enhanced AUV operations.
• The DAVS technology supports the advancement of underwater acoustic sensing and autonomous survey methodologies.