Analysis of 3D localization in underwater optical wireless networks with uncertain anchor positions

Localization accuracy is of paramount importance for the proper operation of underwater optical wireless sensor networks (UOWSNs). However, underwater localization is prone to hostile environmental impediments such as drifts owing to the surface and deep currents. These cause uncertainty in the deployed anchor node positions and pose daunting challenges to achieve accurate location estimations. Therefore, this paper analyzes the performance of three-dimensional (3D) localization for UOWSNs and derives a closed-form expression for the Cramer Rao lower bound (CRLB) by using time of arrival (ToA) and angle of arrival (AoA) measurements under the presence of uncertainty in anchor node positions. Numerical results validate the analytical findings by comparing the localization accuracy in scenarios with and without anchor nodes position uncertainty. Results are also compared with the linear least square (LLS) method and weighted LLS (WLLS) method.