A SINS/CNS Integrated Navigation System Based on High Precision Mathematical Horizon Reference

SINS/CNS integrated navigation system has the advantages of high autonomy and strong anti-interference ability. It has important application value in the navigation tasks of ballistic missiles and reentry vehicles. However, in traditional SINS/CNS integrated navigation system, the mathematical horizon error provided by the SINS diverges over time, leading to a decrease in the accuracy of celestial positioning. As a result, the positioning accuracy of the SINS/CNS integrated navigation system is seriously divergent in long-duration flight. Therefore, this paper elucidates the mechanism by which the inertial navigation system supplies the mathematical horizon reference, analyzes the relationship between mathematical horizon accuracy and celestial positioning error, establishes the relationship model between inertial navigation error and mathematical horizon accuracy, and proposes a high-precision mathematical horizon acquisition scheme. On this basis, a SINS/CNS integrated navigation system is designed based on high precision mathematical horizon reference. The celestial observation angle is obtained by using high-precision mathematical horizon reference, and the altitude information is obtained by introducing an altimeter to estimate and correct the integrated navigation error. Simulation results show that, compared to traditional method, the proposed method significantly improves the precision of integrated navigation by suppressing the divergence of mathematical horizon errors, thereby meeting the requirements for long-duration high-precision navigation missions.