Initial alignment for strapdown inertial navigation system based on inertial frame

A initial alignment algorithm in the inertial frame based on the alignment application of Kalman filter was presented. State and observation equations of strapdown inertial navigation system (SINS) are established using Kalman filter by the gravity vector projected in the inertial frame, and the initial alignment of the SINS based on the inertial frame on stationary base was compared with the alignment based on the geographic coordinate frame. The analysis shows that the heading misalignment´s precision was improved, and this method was proved by simulation.