In mobile underwater environment, underwater wireless sensor networks(UWSNs) keep moving and dispersing due to water flowing and aquatic creatures touching, and thus some isolated nodes appear. This type of isolated nodes cannot obtain enough anchor nodes in their communication range, which makes self-localizations disabled. In order to solve this problem, a multi-hop localization scheme is proposed in this paper. Firstly, ordinary nodes between anchors and unknown nodes are set as routers to find the shortest paths by a greedy approach; secondly, the shortest paths are approximately fitted into a straight distance between two nodes; finally, the positions of unknown nodes can be calculated by trilateration. The proposed algorithm is simulated and is compared with other algorithms in terms of localization error, and the results are proven preferable.

Abstract