Research And Implement On The Monitoring Methods Of Galileo System Time Offset

The current global satellite navigation system mainly includes GPS, GLONASS,Galileo and BDS. With the rapid development of satellite navigation systems, more and more people will recognize the advantages of multi-mode navigation, it has become an inevitable trend of future navigation systems, in order to achieve multi-mode navigation, the focus question that need to be solved is system time compatibility and interoperable.For the rapid development of the navigation system, this paper has carried out a study based on receiving the signal in space to achieve the method of Galileo system time offset monitoring,designs and implements a multi-GNSS receiver data acquisition software which can acquire the data of four satellite navigation system, the performance of Galileo satellites clock in orbit to be assessed, that provides the basis for the multi-mode navigation. Then research on the monitoring method of the Galileo system time offset and complete the design and implementation of Galileo system time offset monitoring software, analysis of UTC(NTSC)-GST monitoring accuracy.Finally, the system time offset monitoring results are evaluated. The main researches are as follows:1.Research on the monitoring methods of GNSS system time offset, this paper focuses on receiving the signal in space to achieve the method of system time offset monitoring, and analyzes the kind of error distribution that impacts the monitoring accuracy.2.Designs and develops a multi-GNSS receiver data acquisition software which can acquire the data of four satellite navigation system, and the performance of Galileo satellites clock in orbit was evaluated. The results showed that: The evaluation results show that the orbit satellite clock frequency stability is(?=60s and?=300s) at e-13 level, and the stability is consistent over time.When the satellite clock time is corrected to the Galileo system time, the Satellite clock stability is slightly improved.3.The Galileo system time offset monitoring platform is built, the preparation of the Galileo system time offset monitoring software is completed to achieve Galileo system time offset real-time monitoring, and monitoring results are analyzed. The results showed that: UTC(NTSC)-GST monitoring accuracy are less than 5ns.4.The system time offset monitoring results were evaluated in two ways, compared with GPS/Galileo system time offset monitoring results and the user-level resolutions in the open environment, and the impact of positioning accuracy by using the system time offset monitoringvalues. the results show that GPS/Galileo system time offset monitoring results has a higher precision.