Using RTKLIB to Implement GPS PPP Time Comparison

GPS PPP time transfer is one of the most important high precision time comparison methods for the international authority's punctuality laboratory. The basic principle of time comparison of GPS PPP is introduced, and the time comparison of GPS PPP is proposed by RTKLIB, then the time comparison results of BRUX, IENG, OPMT and PTBB are verified by examples. The experimental results show that the RMS of time comparison using RTKLIB is about 0.1-0.2 ns, and the stability of the day frequency is about 1.5×10-15-2.5×10-15, The result of time comparison is in good agreement with IGS's final clock offset.