Navigating around an acoustic beacon

We present a simple yet robust sea-glider navigation method in a constellation of drifting Lagrangian drifters under the polar ice cape. The glider has to perform oceanographic measurements; mainly conductivity, temperature and depth, in an area enclosed by the drifters. The glider can not rely on GNSS positioning data as the ice cape makes it impossible to surface. The presented method does not use a localization algorithm to estimate state space model data. The originality of the presented method resides in the use of only one acoustic beacon and a very simple PID controller based on a basic kinematic model. Interval analysis is used to bound the errors in the estimation of the measured value and its derivative in the presence of noise and outliers. Validation is performed through intensive simulations.

Navigating on a circle: vehicle speed: 0.3m/s; North current: 0.15m/s; outliers: 10%; missing data: 10%; circle radius: 10km; data every 20 minutes;

— J.S. —