Fast and precision multiposition initial alignment method of inertial navigation system

The initial alignment of INS is a very important procedure. It is very valuable to the INS used in various weapon and civil system that the best alignment accuracy and speed are obtained in the shortest time. As a rule, the Kalman filter has been used to solve the initial alignment of inertial navigation. The traditional multiposition alignment technique made alignment accuracy of the inertial navigation system enhanced greatly. Because of the poor observability of INS on stationary base, the estimation of the azimuth error will converge very slowly in initial alignment by means of Kalman filter. A fast and accuracy estimation method of the multiposition alignment is proposed for the initial alignment of INS 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 is improved greatly. The computer simulation results illustrate the efficiency of this method.