Research on dynamic two-way time synchronization for air-borne pseudo-satellite in wide area for BD navigation satellite

The high performance time synchronization technology plays an extremely important role in pseudo-satellite augmentation navigation service system. To achieve high timing precision in two-way time synchronization between dynamic air-borne pseudo-satellite and standard time of satellite navigation system, a method based on position compensation is proposed in this paper depending on the characteristics of high-precision in short time of strap-down inertial Navigation systems(SINS). First, the accuracy of relative position in short time is analyzed according to the computing method of SINS system, and then the principle of position compensation is presented to enhance the accuracy of two-way time synchronization when UAV pseudo-satellite is flying. Second, clock error is modeled and Kalman filter is adopted to estimate to time bias and frequency bias. Third, the track iterative algorithm is proposed to solve the problem that signal travelling time of pseudo-satellite and navigation satellite cannot be got directly in the simulation as UAV pseudo-satellite is in flight. Finally, the dynamic two-way time synchronization between pseudo-satellite and navigation satellite is simulated and the results show that this strategy could improve the accuracy of dynamic two-way time synchronization and the timing accuracy is better than 0.2ns.