Collaborative relative positioning in underwater environments using acoustic communication and two-way ranging

This study explores the feasibility of using acoustic communication and two-way ranging for relative positioning in underwater navigation applications which use the GUWMANET® protocol. Propagation time estimations were gathered between multiple nodes in a heterogeneous mobile ad-hoc network during a series of sea trials, which employed two different physical layer methods along with double-sided two-way ranging (DS-TWR). Following this data collection, multidimensional scaling was applied to the estimated propagation-time matrix to generate relative positions in Euclidean space, resulting in a topology that was subsequently compared to GPS data for validation purposes. In order to enhance the accuracy of the topology estimation process, the classical multidimensional scaling algorithm was adapted to incorporate extrinsic information, such as the known depths of surface vehicles. The real-world performance is compared to the performance of the system achieved through simulations using the DESERT underwater network simulator. Furthermore, the limitations of the acoustic communication schemes are derived to provide valuable insight into the feasibility of real-time navigation in complex underwater environments.