An Underwater Positioning Scheme for 3 D Acoustic Sensor Networks

We transform the 3D underwater positioning problem into its 2D counterpart via a projection technique that employs depth information available to underwater sensors. After showing that a non-degenerative projection preserves network localizability, we present a purely distributed localization scheme termed USP for underwater acoustic sensor networks. In USP, reference nodes are projected to the plane that contains a tobe-localized sensor, and elegant two dimensional localization techniques are applied when the projection is non-degenerative. USP is shown to have improved localization capabilities over existing 3D methods through theoretical analysis and extensive simulation.