Underwater vehicle trajectory estimation using contracting PDE-based observers

This paper addresses the issue of estimating underwater vehicle trajectories using Gyro-Doppler (body-fixed velocities) and acoustic signals (earth-fixed positions). The approach consists of diffusion-based observers processing a whole trajectory segment at a time, allowing to consider important practical problems such as different information update rates, outages, and outliers in a very simple framework. Results of H. Nijmeijer and T.I. Fossen, (1999) are used to prove that the observers are contracting, i.e. convergent in the sense of contraction analysis. Simulation and experimental results are presented to illustrate the potential of application of the method.