Cube-scan-based three dimensional localization for large-scale Underwater Wireless Sensor Networks

As a distributed underwater network with wireless sensors, Underwater Wireless Sensor Networks (UWSNs) can provide the means for real-time, accurate and extensive monitoring, it is considered as an ideal system for extensive aqueous environment surveillance. Although localization has been widely studied for terrestrial WSNs, the adverse aqueous environments and harsh acoustic communications all bring new challenges for UWSNs and make it necessary to develop new localization schemes. In this paper, we propose a novel cube-scan-based three dimensional (3D) multi-hop localization algorithm for large-scale UWSNs. Firstly, based on the geometric constraint relationship and the depth information of sensor nodes, we effectively restrict the scope of the to-be-localized node position by a feasible set. Then we study the factors that influence the multi-hop distance estimation, a weighted constrained multi-hop localization model has been constructed. Finally, the feasible set is divided into some sub-cubes of equal size, the approximately optimal values of nodes´ coordinates can be obtained through a cube-scanning procedure. Simulation results show that our scheme can achieve high localization accuracy with low communication overhead in large-scale UWSNs.