GNSS system time offset monitoring at NTSC

GNSS System time offset between two satellite navigation systems is one of the most important aspects of their interoperability and compatibility. This paper introduces the research work of GNSS System Time Offset Monitoring at NTSC. The method of GNSS System Time Offset monitoring by Signal-in-Space Reception is described. Multi-GNSS receiver calibration is the key technology of GNSS system time offset monitoring. The causes of Inter-System biases and Inter-Frequency biases are researched and so does their calibration method. The calibration results are showed and analyzed. The key technologies of BDs system time offset monitoring are researched which include the algorithms related to satellite equipment group delay and dual-frequency ionosphere delay correction whose measurement result is illustrated. And then, the system time offset monitoring results of UTC(NTSC)-GPST and UTC(NTSC)-GLONASST and UTC(NTSC)-BDT for several months long are showed respectively.