In-Motion Alignment Method of SINS Based on Improved Kalman Filter under Geographic Latitude Uncertainty

To realize the in-motion alignment of strapdown inertial navigation system (SINS) under geographic latitude uncertainty, we propose a estimation and method based on integral dynamic window polynomial fitting (IDW-PF) improved Kalman filter (IKF). First, (IDW) is designed to smooth out high-frequency line motion interference accelerometer noise. Second, specific force performed for cubic (PF) with time as an independent variable further suppress interference. Simultaneously, estimated according geometric relationship between angle gravitational acceleration vectors at different moments latitude. Finally, IKF multi-fading factor SINS. A simulation experiment conducted verify proposed method. The results indicate that can be well by IDW-PF; mean standard deviation achieve ?0.016° 0.013° within 300 s. trapezoidal maneuvering path optimal when used, pitch error 0.0002°, roll 0.0009° heading ?0.0047° after ends 900