Surface Based Anchor-Free Localization Algorithm for Underwater Sensor Networks

Localization in underwater environments has been constrained by the dependencies on the line of sight (LOS) due to the challenging variability´s of the environment. This dependency hinders node discovery and ad-hoc formation in underwater networks and limits the performance of routing protocols. Most proposed algorithms in the literature rely on anchor nodes that are at fixed positions to serve as reference points, which is not practical in many applications. This paper introduces a novel approach to the localization problem that allows for node discovery without depending on the LOS and any fixed reference nodes. In the proposed surface-based reflection anchor-free localization (SBRAL) algorithm all nodes will apply homomorphic deconvolution to establish a water-surface-reflected communication link. SBRAL then creates a relative coordinate system where every node in the network identifies others nodes by increasing the SBRAL transmit angle and using the reflection points on the water surface as temporary reference points. The simulation results confirm the effectiveness of the proposed SBRAL algorithm.