High-precision time synchronization of kinematic navigation system using GNSS RTK differential carrier phase time transfer

Time synchronization is a fundamental requirement of radio navigation systems, and it is essential for real-time high-precision positioning in emergency applications such as fire scenes and military operations. For urgent positioning requirements without effective positioning means, a radio kinematic navigation system, which can be quickly deployed, is designed based on the Global Navigation Satellite System (GNSS) space–time reference. Firstly, aiming at the time difference between system stations, a Real Time Kinematic-Differential Carrier Phase Time Transfer (RTK-DCPTT) method based on Global Positioning System (GPS) common view principle is proposed. This method can solve the interstation time difference in real time with high precision by using sequential least squares recursion technique. Secondly, interstation time synchronization method based on RTK-DCPTT is proposed by using Pulse Per Second (PPS) signal trigger and clock correction. Thirdly, PPS signal stability and availability are evaluated. Fourthly, clock difference consistency between PPS signal acquisition and RTK-DCPTT approach is analyzed. Finally, a signal synchronization measurement system of kinematic navigation system is designed and time synchronization performance is evaluated. Experimental results demonstrate the feasibility of real-time high-precision signal synchronization method based on RTK-DCPTT technique for kinematic navigation system.