Extended GNSS Common View Using Multi-Constellation and Multi-Frequency-Code Signals

We extended the standard GPS Common-View (CV) time transfer method, which traditionally uses only the GPS P3 dual-frequency code combination, to include all measured GNSS frequency code (FRC) signals. By averaging the 30-second CGGTTS [1] CV results from GPS (L1C, L2C, C5, L1P, L2P) and Galileo (E1, E5, E5a, E5b) FRC signals, previously unused data from standard CGGTTS files can be leveraged to improve time transfer precision. To validate the extended GNSS CV (eCV) method, we conducted a 30-meter baseline common-clock test and compared its performance with the standard GPS P3 CV. The results demonstrated that eCV offers more precise remote time comparison than the traditional GPS P3 CV method, making it a more effective tool for synchronizing remote clocks—particularly in the case of rubidium (Rb)-disciplined systems. Additionally, we applied eCV in a test involving a 20-kilometer baseline to measure a rubidium clock using a receiver module. The results showed that, when the remote clock is an Rb oscillator and the baseline is short, the eCV method performs comparably to the Precise Point Positioning (PPP) technique. Importantly, eCV delivers real-time results and does not rely on external information, offering a practical advantage in certain applications.