Experimental validation of magnetic navigation of marine robotic vehicles*

:This paper describes the work developed towards the implementation of magnetic navigation (MAGNAV) methods for small, affordable underwater robotic vehicles. MAGNAV constitutes a particular implementation of a broader class of methods designated as geophysical navigation, which encompasses the already classical terrain-aided, or terrain-referenced, navigation approach. Relying on prior work by the authors, the paper proposes a particle filter navigation algorithm which may be combined with other position estimation methods to increase the robustness of the estimation process. The results of a series of tests performed in the water with a marine robotic vehicle in order to assess the impact of different sensor-vehicle configurations on the quality of the magnetic data used in MAGNAV are reported. The magnetic navigation solution proposed is validated in simulated trials using real magnetic and navigation data acquired with an autonomous marine vehicle in real trials using standard navigation sensors and an affordable total field magnetometer. The results obtained illustrate the high potential of the approach for geophysical navigation of autonomous underwater vehicles.