Multi-position alignment technique of DTG SINS

The error of inertial measurement unit (IMU) is the key factor affecting the accuracy of the impact point of navigation systems. Considering how to increase the accuracy of dynamically tuned gyroscope (DTG) gyros with known heading information, the multi-position alignment technique is used in the on-line IMU calibration. The determinant method is applied to the analysis of the observability of the gyro static drift errors. The usual theoretical analysis of two-position alignment technique is presented, as well as the limited equation of optimal three-position alignment. The results demonstrate that the optimal three-position alignment is able to make the gyro static drift errors of DTG completely observable. Besides, the influence of the system errors can be eliminated effectively.