Time-difference-of-arrival-based localization methods of underwater mobile nodes using multiple surface beacons

Abstract

In this paper, we investigate the mobile node localization problem in an underwater positioning system using multiple surface beacons, where time synchronization between the surface beacons and underwater mobile nodes is not required. First, we propose a Time-Difference-of-Arrival-based (TDoA-based) node localization method. In the proposed method, as the underwater node receives the positioning messages from more than or equal to three surface beacons belonging to the same grid at one epoch, it calculates the location by itself using the information of received positioning messages and the corresponding arrival times. To deal with the problem that the number of received positioning messages at one epoch by the underwater node is not enough for the location calculation, we present the modified TDoA- based node localization method with buffered messages and the modified TDoA-based node localization method with motion information. The effectiveness of proposed TDoA-based node localization method and two modified methods is validated by simulation results and sea experiment data analytical results. The robustness of the TDoA-based node localization method is improved by two modified methods. Moreover, using the proposed TDoA-based node localization method and two modified methods, the underwater node can localize itself in low energy consumption and passive mode.