Study on localizability judgment in underwater sensor networks based on skeleton extraction and rigidity theory

Underwater sensor networks (UWSNs) can be applied in sea resources reconnaissance, pollution monitoring and tactical monitoring etc., and it has become a hot field in wireless sensor networks. In the three dimensional underwater space, it is a key topic to judge the localizability of the unknown sensor node in all kinds of applications. In this paper, a localizability judgment method for UWSNs is proposed based on skeleton extraction and Rigidity Theory. Firstly, UWSNs is converted to an undirected graph. Secondly, by eliminating its pseudo node and cutting edge, the graph will shrink to the sub-graph with global rigidity, which is named “ network skeleton”, and then the localizable nodes are figured out. Lastly, Analytic Hierarchy Process is used to evaluate the localization credibility of the localizable nodes. The extensive simulations demonstrate that the proposed localizability judgment method can achieve excellent success ratio and efficiency in the networks with different sensor numbers, sensor density and connectivity.