Accuracy Analysis of Disturbing Gravity on Long-Distance Strapdown Inertial Navigation System

With the continuous improvement of the precision of the inertial measurement unit (IMU), the error caused by the traditionally neglected disturbing gravity to the actual navigation cannot be ignored in the high-precision inertial navigation system (INS). This paper focuses on the mechanism of the influence of disturbing gravity on actual inertial navigation. Specifically, by deriving the error propagation equation of strapdown inertial navigation system (SINS) under the consideration of disturbing gravity, we have completed the analysis of error propagation characteristics under different conditions through simulation. Furthermore, we completed the analysis of the influence characteristics of the disturbing gravity on the long-range flighting vehicle navigation errors and clarified the coupling influence mechanism of the disturbing gravity on the navigation accuracy.