A Fast and Precision Initial Alignment Method for Strapdown Inertial Navigation System

Although the tradition muliposition alignment technique made the strapdown inertial navigation system (SINS) having high alignment accuracy, the poor observability of SINS on stationary base, the estimation of the azimuth error will converge very slowly in initial alignment by means of Kalman filter. In this paper, a fast and accuracy estimation method of the multiposition alignment azimuth error is creatively proposed for the initial alignment of SINS on stationary base. On the basis of the fast converge of the leveling error, the azimuth error can be directly calculated. By means of this fast and accuracy initial alignment method, not only the precision of initial alignment is increased, but also the speed of initial alignment is greatly improved. The computer simulation results illustrate the efficiency of this method.