A fast initial alignment method with gyro angular rate information

Based on the error model of SINS, a fast initial alignment method for SINS is proposed, which uses both the velocity errors and the angular rate errors as the observation of the system model. The observation equation with gyro angular rate information is derived in detail, and the qualitative analysis of observability and the quantitative calculation of observability degree are given. Compared with the method using only velocity errors as the observation, this method makes full use of the external information. As a result, the observability degree of the system is raised, and the time spent on initial alignment is shortened. The rapid reaction capability and the rapid mobility capability of the system are greatly enhanced.