AUV assisted asynchronous localization for underwater sensor networks

Underwater sensor networks (USNs) have been identifies as a promising technology to monitor and explore the underwater environment. Most applications of USNs demand reliable and accurate localization for sensor nodes. However, mobility and clock asynchronous characteristics on underwater sensor nodes make it challenging to achieve localization. In this paper, we are concerned with AUV assisted asynchronous localization problem for USNs, where AUVs run as mobile nodes and reference points. A tracking variance threshold is set to determine the occasion of localization process. The node need to be localized performs the localization protocol and communicates with the anchor nodes. Then, a method of time difference is used to eliminate the effects of asynchronous clocks. During the localization, a motion compensation method based on estimation is proposed to compensate the movements of nodes. In addition, the localizing errors due to velocity estimation are analyzed in error analysis. At last, simulation results confirm the efficiency of the proposed algorithm.