Localization, tracking, and imaging of targets in wireless sensor networks: An invited review

Wireless sensor networks (WSNs) have shown many attractive features in a lot of real-world applications that motivate their rapid and wide diffusion. One of the most challenging topics when dealing with WSNs is the localization and tracking of objects from measurements collected by the nodes themselves. Once distributed in a region without the knowledge of their positions, the nodes actively take part in the localization of the network as well as to the detection and monitoring of the presence and movements of targets lying within the sensed area. This paper reviews state-of-the-art systems and approaches developed for WSN-based localization and tracking of active as well as passive targets. The main focus is on systems that exploit the strength of the received signal, always available at the WSN nodes, without ad hoc or additional hardware. Recent strategies for WSN-based imaging are discussed as well.