AUV-Aided Joint Localization and Time Synchronization for Underwater Acoustic Sensor Networks

For the purpose of localization and time synchronization of underwater sensor networks, buoys are generally distributed on the sea surface of the area of interest, serving as fixed anchors. However, this method is not economical and has poor scalability. An alternative is to employ an autonomous underwater vehicle (AUV) as a mobile anchor. By receiving the periodical broadcast signals from the AUV, any sensor in the communication range can measure time of arrival of received packets and obtain a series of nonlinear equations. In this letter, we proposed an efficient linear algorithm to solve the nonlinear equations, and gave closedform positioning and synchronization error analysis. Besides, we show that the proposed method can approach the Cramer-Rao lower bound by both theoretical analysis and simulation.