Solar-Tracking for Integrated Orientation Based on the Degree of Underwater Polarization

Solar-tracking is one of the key issues in underwater polarization navigation. Most existing studies are based on the Angle of Underwater Polarization (AoUP). As water depth increases, however, the AoUP is disturbed by multiple scattering, while the Degree of Underwater Polarization (DoUP) maintains a stable relative relationship. To address the less robustness of polarization navigation, a solar-tracking and integrated orientation method based on DoUP is proposed. In consideration of the refraction, the relationship between the solar position and DoUP is established based on the maximum Degree of Polarization. Moreover, an integrated navigation model is developed aided by the solar position. Results from the static experiment in water tank and dynamic sea trials demonstrate that the proposed method exhibits improved accuracy and robustness compared to the AoUP method. This article presents a potential approach to improve the adaptability of underwater autonomous orientation.