A test of precision GPS clock synchronization

This paper describes tests of precision GPS time transfer using geodetic-quality TurboRogue receivers. The GPS data are processed with the GIPSY-OASIS II software, which simultaneously estimates the GPS satellite orbits and clocks, receiver locations and clock offsets, as well as other parameters such as Earth orientation. This GPS solution technique, which emphasizes high accuracy GPS orbit determination and observable modeling, has been shown to enable sub-1 ns time transfer at global distance scales. GPS-based monitoring of clock performance has been carried out for several years through JPL's high precision GPS global network processing. The paper discusses measurements of variations in relative clock offsets down to a level of a few tens of picoseconds. GPS-based clock frequency measurements are also presented.