Passive localization improves underwater vehicle tracking despite wave motion
Wave-Robust Passive AUV Localization Using FP-MUSIC
Robotics
Summary
Tracking underwater vehicles without setting up special equipment on the seabed or relying on their own sensors is hard because waves move the floating receiver and distort signals. The authors created a method that uses a sensors on a floating buoy to correct for wave motion and better figure out where the vehicle is in 3D. Their technique processes signals more accurately by adjusting for movement and helps distinguish signal directions and distances. In tests on fake wave data, their method improved location accuracy substantially over previous ways.
What this means in practice
- •For marine robotics teams: Enable precise 3-D tracking of underwater vehicles using a single surface buoy without seabed equipment under wave conditions.
- •For environmental monitoring operators: Provide accurate passive localization of sensors or vehicles in marine environments affected by surface waves.
Authors
Usama Saqib, Ola Rønning, Andrzej Wąsowski
Abstract
Localizing an autonomous underwater vehicle without pre-deployed seabed transponders, or direct access to onboard vehicle sensors remains a core challenge. We present a receiver-passive 3-D localization and spatial mapping system utilizing a single floating surface buoy equipped with a hydrophone array and an inertial measurement unit (IMU). The central difficulty is that surface wave motion induces six-degree-of-freedom (6-DOF) perturbations that rotate the array between snapshots, degrading conventional subspace processing. We resolve this by introducing a fixed-point iterative MUltiple SIgnal Classification algorithm (FP-MUSIC) that uses IMU measurements to de-warp snapshot covariances prior to direction-of-arrival estimation. Furthermore, we employ a subspace-projected wideband matched filter to resolve beacon ranges and use power asymmetry for independent front-back identification. Evaluations across simulated sea states demonstrate that FP-MUSIC substantially reduces localization error relative to uncompensated methods and sustains robust 3-D tracking and vehicle orientation estimation under wave-induced motion. At moderate sea state, FP-MUSIC increases the 2-m beacon-separation accuracy from approximately 45% to 75%.