A Mobile-beacon Based Iterative Localization Scheme in Underwater Acoustic Sensor Networks

The accurate localization of nodes is one of the most basic tasks in Underwater Acoustic Sensor Networks (UASNs). It is essential for sensor nodes to obtain their location information. The underwater sensor nodes cannot directly use the Global Positioning System (GPS) to collect their location information, so it is necessary to design an underwater localization scheme to realize the localization of these nodes. In this research, there are two problems worth studying: First, how to use finite number of beacon nodes to increase the percentage of localized nodes in the network, and second, how to reduce the localization error caused by many factors. In this paper, we use several noncollinear beacon nodes which can only be moved vertically to broadcast their location information to the surrounding unknown nodes at fixed time intervals. If an unknown node has already been localized, it can be used as a reference node and further broadcast its location information to the remaining unknown nodes, so as to realize iterative localization. Simulation results show that the proposed localization scheme can not only achieve a higher proportion of localized nodes in a shorter time, but also effectively reduce the localization error.