Comprehensive correction technology of strapdown inertial navigation system based on position information

For platform inertial navigation system, the carrier should be limited under the state of low speed and same latitude when comprehensive correction. In order to solve this problem, the comprehensive correction technology of strapdown inertial system (SINS) based on inertial coordinate system was proposed. For traditional two point comprehensive correction algorithm which needed the accurate azimuth information, but because of the installation deviation, the accurate azimuth information could not be deserved, algorithm of three point comprehensive correction was employed. The relationship between of gyro drifts and azimuth errors could be developed based on intermittent external position information, and the least square algorithm was used to evaluate gyro drifts and compensate azimuth errors. Theoretical and experimental analysis show that when the SINS works under the state of horizontal damping, three point comprehensive correction method would not be affected by the carriers' motion state and could compensate azimuth error accurately, thus significantly improving positioning accurate of low precision SINS.