Co-operative use of marine autonomous systems to enhance navigational accuracy of autonomous underwater vehicles

This paper gives the first results from a research programme that aims to develop efficient navigation techniques for long range Autonomous Underwater Vehicles (AUVs) conducting ocean basin transits using low power sensors. The results results relate to the development of and on-line and low power cooperative navigation scheme between an AUV and an Unmanned Surface Vehicle (USV), where the latter acts as an acoustic tether for localization error reduction. Most of the computations are executed on the USV in order to reduce the power requirements of the AUV. The methodology is assessed by numerical simulation, where the Dead Reckoning (DR) error is modelled using data obtained from field trials and the result show that considerable estimation error reduction is possible even in very deep water operations.