A Network Navigation System With Opportunistic Use of One-Way and Two-Way Acoustic Ranging: the DANS20 Experience

The NATO STO Centre for Maritime Research and Experimentation (CMRE) has developed a system for acoustic-based navigation which relies on the addition of localisation services to an underwater network. In particular, timing information about packet transmission and reception is encoded and transmitted acoustically for cooperative network localization and navigation. This paper presents our recent research on this topic where networking protocols are exploited to increase the collection of ranging measurements, based on one-way and two-way travel time. Results collected during the DANS20 trial, conducted in December 2020 in front of the Palmaria Island (Italy), demonstrate that in our system, which does not use expensive atomic clocks, one-way ranging can help increasing the opportunities of range measurements with similar measurement errors if compared to two-way ranging. This is a step forward towards the development of a deep-water navigation system suited to real-world surveillance scenarios, where the number of beacon nodes is limited and a vessel cannot support the AUV navigation.