Distributed Localization With A Mobile Beacon For 3D Underwater Acoustic Sensor Networks

In recent years, underwater sensor networks (UWSNs) are widely applied to the fields of science, technology, military affairs and environment. And the localization technology is a needed factor for UWSNs. The research on the localization for UWSNs has become one of the important problems that the researchers pay much attention to. Some researchers took a cue from the land wireless sensor networks (WSNs) localization method, and proposed some UWSNs location methods. In these methods,some needed several anchors that increased the cost, and the others transmitted the three-dimensional environment into two-dimensional that increased the average error and reduced the node coverage.In this paper,we propose a distributed Localization with a Mobile Beacon (DLMB),which uses an Autonomous Underwater Vehicle (AUV) as the mobile beacon. The AUV moves in the 3D water environment with predefined path sending beacon signals with a constant interval towards the sensor nodes. These sensor nodes are localized individually by receiving the beacon signals passively without inner communications. For location estimation,a set of beacon signals that one sensor node received are intersected, and form an Innermost Intersection Body (IIB). At different time, the shapes of these IIBs are different, and then we compute the centroids of these different IIBs as the locations of the sensor nodes. We use MATLAB to simulate our localization method and LDB which also uses an AUV to locate sensor nodes in the 3D underwater environment, and the results show that our proposed localization solution can achieve higher localization coverage with relatively smaller localization error than LDB when the interval increases.