Improved Underwater Polarization Heading Determination via INS/PS Integration: Considering the Influence of Light Refraction

Polarization navigation is an emerging autonomous navigation technology suitable for unmanned underwater vehicles (UUVs). Nonetheless, light refraction poses challenges for underwater polarization navigation as it alters the direction and amplitude of the polarization electric vector (E-vector). In this article, we propose a novel underwater heading determination method with inertial navigation system/polarization sensor integration in consideration of light refraction. In view of light deflection and energy attenuation under refraction, the direction correction matrix and amplitude compensation factor are established for the E-vector. On this basis, the refracted E-vector is introduced into the heading measurement model, which can reduce modeling errors induced by refraction, thereby producing a better prediction of heading information. In addition, a dual-filter algorithm is constructed to handle fusion models with different characteristics, improving the reliability and efficiency of heading estimation. Numerical simulation is conducted to confirm the feasibility of the proposed method, while ocean navigation experiments on UUV are carried out to evaluate its accuracy.