Vision-Enabled Node Localization in Wireless Sensor Networks

We introduce novel localization techniques for wireless image sensor networks. Based on visual observations between the image sensor nodes or simultaneous observations of a moving object by several nodes, the proposed schemes employ simple image processing functions to obtain angular bearing information between the nodes in a neighborhood and solve for the node positions. We will first propose a technique to localize nodes relative to a coordinate system defined by two reference nodes and propagate the topology information throughout the network. In a different scheme, we consider cases where simultaneous observations from a moving target are used by several image sensors to jointly estimate the coordinates of the nodes as well as those of the target. We will also propose a technique in which the assumption of a simple motion pattern for the target allwos for a collaborative scheme for finding relative location information between the nodes. In a fourth scheme, assistance from a moving beacon knowing its location information is used to localize a network of image sensors. The proposed algorithms are based on in-node processing and local collaboration between the nodes and hence are scalable to large networks. Simulation and experimental results are provided to verify the performance of the proposed techniques.