Acoustic receiving on glider-type autonomous underwater vehicles: Advantages and challenges

Abstract

An ocean glider is a specific type of Autonomous Underwater Vehicle (AUV) that operates using a buoyancy engine rather than traditional propellors or thrusters. This method of propulsion enables a glider to be deployed for weeks or months and is relatively quiet, making the ocean glider a desirable platform for persistent acoustic monitoring. A glider typically remains submerged for several hours, during which time it can be challenging to localize the vehicle precisely. Gliders are low-power platforms that operate in the mid-water column, and therefore subsea navigation technologies implemented on other types of AUVs, such as inertial navigation systems aided by Doppler velocity logs, may not be suitable. Acoustic signals from fixed broadband sources have been used for subsea localization of Seaglider, a commercially available glider platform. Measurements of the multipath acoustic arrival structure received on Seagliders at ranges up to hundreds of kilometers from transmitting sources were used for vehicle localization in both temperate and polar underwater sound propagation environments. Methodology and results for subsea localization of the Seaglider platform will be presented and placed in the context of a broader discussion of the advantages and challenges specific to the glider as a moving acoustic receiving platform.