Localization and Tracking for AUVs in Marine Information Networks: Research Directions, Recent Advances, and Challenges

In marine information networks, localization information is crucial for AUVs to label their collected data as well as to support intelligent auto-navigation or timely remote control. However, the extremely hostile underwater environments impose a number of challenges on designing AUV localization and tracking algorithms that can strike flexible balances among energy, accuracy, and practicability. To deal with these challenges, this article provides a systematic research roadmap for AUVs' localization and tracking, spreading from anchor deployment to time synchronization and range estimation and to trajectory prediction. Specifically, we first review the existing research on anchor deployment schemes, based on which we propose a spatially circular deployment configuration that achieves higher localization accuracy and discuss the anchors' number determination problem for balancing the energy-accuracy tradeoff. We then describe the principles for time synchronization and range estimation and summarize their state-of-the-art research advances. Finally, after introducing some widespread trajectory tracking methods, we develop a Kalman filtering based trajectory prediction algorithm to compromise tracking accuracy and signaling overheads. In particular, we also present and analyze the related open issues and challenges in each direction for future investigations.