A method improving the alignment accuracy of medium accuracy MEMS inertial navigation system on revolving base

In initial alignment for a medium accuracy MEMS strapdown inertial navigation system on a stationary base, when the Kalman filtering algorithm is adopted in initial alignment, as the east gyro drift rate cannot be estimated, it yields a constant error in the estimation of the azimuth misalignment angle. To, improve the alignment accuracy, a novel alignment method on revolving mounting base is proposed. The Strong Tracking filter algorithm of extending the measured values is studied. The theory of spectral condition number is utilized to analyze the degrees of observability of states. Simulation results show that the estimation accuracy of the azimuth misalignment angle has been improved greatly through revolving the mounting base and the method proposed in this paper is efficient in initial alignment for a medium accuracy MEMS SINS.