Energy-Efficient Target Tracking With UASNs: A Consensus-Based Bayesian Approach

Target tracking has been considered as one of the most important applications of underwater acoustic sensor networks. However, the long propagation delay, high-energy consumption, and strong noise properties of the underwater environment make target tracking more challenging as compared with terrestrial sensor networks. This article is concerned with an energy-efficient tracking issue for underwater targets, subject to an asynchronous clock, power restriction, and noise measurement constraints. The tracking process can be divided into two phases, i.e., position acquisition and persistent tracking. In the first phase, we establish the relationship between propagation delay and position, through which an asynchronous localization algorithm is developed for sensor nodes to estimate the position of target. Based on the estimated position, a consensus-based Bayesian filter is designed for sensor nodes in the second phase to enable persistent tracking. In particular, the consensus fusion strategy and duty-cycle mechanism are jointly adopted to improve the tracking accuracy and prolong the network lifetime. Moreover, the convergence analyses for the proposed approach are also presented. Finally, simulation and experimental results reveal that the proposed tracking approach can reduce the influence of malicious measurements, while the energy efficiency can be significantly improved as compared with the other works. Note to Practitioners—Underwater target tracking is aimed to acquire precise location and achieve sustainable monitoring for a target. It has important practical significance to enhance marine observing ability. Currently, the most favorable carrier for underwater communication is still the acoustic wave. However, due to the unique characteristics of acoustic communication, the tracking schemes developed for the terrestrial environment cannot be directly applied to underwater acoustic sensor networks. With this as motivation, we develop an energy-efficient tracking approach for underwater targets. The tracking approach developed in this article exploits timestamp measurement, consensus fusion strategy, and duty-cycle mechanism to capture the unique characteristics of acoustic communication. To better use this approach for target tracking, two factors should be highlighted: 1) the clocks between target and sensors are not required to be synchronized and 2) the sensor nodes are not always demanded to retain the active mode. Simultaneously, it is more meaningful from the view of marine engineering to design the control and communication platforms. Simulation and experimental results suggest that the proposed tracking method is feasible and has superior performance as compared with the existing methods. Hopefully, our tracking strategy can provide valuable theoretical and technical support guidance to the practicing marine engineer for the co-design of control and communication.