This paper discusses a node selection problem for bearings-only tracking in wireless sensor networks (WSNs). Saving energy and prolonging the lifetime of the network are the research focuses due to the severely constrained resource of WSNs. An energyefficient network management strategy is necessary to achieve good tracking performance at low cost. In this paper, an energyefficient node selection algorithm for bearings-only sensors in decentralized sensor networks is proposed. The residual energy of a node is incorporated into the objective function of node selection. A new criterion of node selection is also made to coordinate with the objective function. Compared with the other common methods, the proposed method can reduce the cost of the entire network, balance nodes energy expenditure, and extend the lifetime of network. Simulation results prove the effectiveness of the proposed method and show good performance in tracking accuracy and energy consumption. consume extra energy because of selecting cluster members and controlling the tracking, and the node selection also neglects the angular diversity of nodes. In [12], a user selection scheme is presented to minimize the overhead energy consumed by cooperative spectrum sensing in a cognitive radio sensor network. This method can conserve energy and achieve reasonably acceptable spectrum sensing accuracy, but it only focuses on the sensor node with a cognitive radio. Zhao et al. [13] propose an informationdriven sensor querying (IDSQ) and data routing approach, which employs a mixture of both information gain and cost as the objective function for node selection. This method introduces Mahalanobis distance as a measure of information utility and defines an entropy based information-theoretic measure. However, Mahalanobis distance can be only applied to the range sensors, and the entropy is difficult to compute in practice. Besides, an entropy-based sensor selection heuristic approach is presented in [14] . Although it shows good accuracy for target localization, this approach has high computational complexity. More details and algorithms about node selection can be found in [15] [16] [17] [18] [19] [20] [21] [22] [23] [24] [25] . This paper works at a distributed network consisting of bearings-only sensor nodes, that is, microphone sensors arrays, which give direction of arrival (DOA) estimations for tracking [26] . In the distributed system, there is no processing center for nodes to send their observations [27] . All information is also processed locally on nodes. The distributed network is considered in this paper for the following reasons. On one hand, the distributed system is insensitive to the changes of the network topology by nodes addition, remove, or failure. On the other hand, the transmission range is much shorter than the centralized network, thereby saving energy and cost. In this paper, we propose an energy-efficient node selection algorithm for bearings-only target tracking. The goal of our algorithm is to provide greatest improvement to tracking accuracy at the lowest cost and balance the energy consumption between nodes. Therefore, we redefine the information utility brought by nodes, incorporate the residual energy of nodes into NSP, and make a new criterion for node selection. The rest of this paper is organized as follows. Section 2 introduces the system model, the decentralized extended Kalman filter (DEKF), and the foundation for node selection. In Section 3, the proposed method and other common methods (ANS, GNS, and CLT) are described in detail. The simulation results are given in Section 4. Finally, Section 5 concludes the paper.
In REF , an energy-efficient node selection algorithm for bearingsonly sensors was proposed.
An Energy-Efficient Node Selection Algorithm in Bearings-Only Target Tracking Sensor Networks
International Journal of Distributed Sensor Networks
Computer Science