Study on a new time synchronization method for underwater targets and vehicles

The highly precise time synchronization is very important to underwater acoustic (UWA) networks (UANs) and underwater targets and vehicles. It consists of a variable number of sensors and vehicles that are deployed to perform collaborative monitoring tasks over given area. The UANs are envisioned to enable applied widely for oceanographic data collection, pollution monitoring, offshore exploration, disaster prevention, assisted navigation and tactical surveillance applications. In the paper, the main purpose is to provide highly precise time synchronization method for the underwater objects. The general designing scheme, the theory of the underwater orientation and navigation and the method of signal processing were given. The results of the underwater experiments show that the precision of time synchronization are 10 ns, 30 ns for a 100 m (stationary) baseline and a 8 km baseline respectively. The experiments also indicate that the major influence factors are complicated for the underwater time synchronization networks and objects.