Time synchronization accuracy refinement for mobile shallow water acoustic sensor network

Time synchronization is an important factor to take into account when performing collaborative and distributed tasks along a sensor network. Message exchange based time synchronization algorithms ported to underwater acoustic sensor networks, have to deal with high latency communications, besides frame Doppler scaling and frame detection at the receiver side, which are key points for an accurate synchronization. Furthermore, mobile sensor networks lead to different propagation times in a bidirectional message exchange, such as the ones used to synchronize two sensors. In addition to time synchronization algorithm, a first order kinematic model in conjunction with Doppler estimation can be applied to precise frame time stamping and avoid drift between clocks. In this paper we present a complete time synchronization scheme optimized for mobile network, tested in simulation and experimented in real tests demonstrating high performance in time synchronization accuracy.