Recent Advances in Synchronous-Clock One-Way-Travel-Time Acoustic Navigation

This paper reports recent results in the development and deployment of a synchronous-clock acoustic navigation system suitable for the simultaneous navigation of multiple underwater vehicles. The goal of this work is to enable the task of navigating multiple autonomous underwater vehicles (AUVs) over length scales of (D(100 km), while maintaining error tolerances commensurate with conventional long-baseline transponder-based navigation systems (O(1 m)), but without the requisite need for deploying, calibrating, and recovering seafloor anchored acoustic transponders. Our navigation system is comprised of an acoustic modem-based communication/navigation system that allows for onboard navigational data to be broadcast as a data packet by a source node, and for all passively receiving nodes to be able to decode the data packet to obtain a one-way travel time pseudo-range measurement and ephemeris data. We present field results for a two-node configuration consisting of a surface ship acting as a global navigation aid to a Doppler-aided AUV