An on-line correction method of initial alignment error of SINS for ballistic missile

Abstract

The initial alignment needs to be implemented before vertical launching of the ballistic missile, while the strap-down inertial navigation system (SINS) has a large alignment error by independent alignment. In order to improve the initial alignment accuracy of SINS for the ballistic missile, the initial alignment error propagation model is established, and the discrete Kalman filter with initial alignment error as the state variable is designed. Based on SINS/GPS integrated navigation system, the initial alignment error is corrected and compensated on line. The simulated results show that the obtained model can reflect the initial alignment error well, the initial horizontal attitudes error precision are within 20” and the initial azimuth error precision is within 50 and proves the accuracy of the initial alignment error propagation model of SINS, and improves the navigation accuracy of SINS effectively.