Joint Sensor Position Calibration and Target Localization Based on Information Interaction for Underwater Acoustic Sensor Networks with Asynchronous Clocks and Sensor Position Errors

Unlike terrestrial environments, the unique characteristics of underwater acoustic channels and dynamic underwater environments pose significant challenges for precise clock synchronization between sensor nodes in underwater acoustic sensor networks (UASNs). Additionally, sensor nodes may drift due to ocean currents and other underwater activities. These two factors significantly degrade the target localization accuracy. This paper investigates a cooperative localization scheme based on information interaction for UASNs under asynchronous clocks and proposes a closed-form solution for joint sensor position calibration and target localization to improve the target localization accuracy. First, we design a cooperative localization scheme that enables range measurements between sensors and between sensors and target. Then, using a Gaussian noise model, we derive the Cramér-Rao lower bounds (CRLBs) for sensor position calibration and target localization. The CRLB theoretical analysis and simulation demonstrate that range measurements between sensors can effectively calibrate sensor positions and improve the target localization accuracy. Based on the scheme, we propose an algebraic closed-form solution for joint sensor position calibration and target localization, leveraging range measurements between sensors to calibrate sensor positions and enhance the target localization accuracy. Under two mild conditions, the theoretical analysis shows that the proposed closed-form solution can achieve the CRLB accuracy of sensor position calibration and target localization. Simulations validate the performance of the proposed method and the theoretical analysis, demonstrating that the proposed method can significantly calibrate sensor positions and improve target localization accuracy compared to other methods.