We report on a study of the carrier-phase time transfer boundary discontinuity by the use of the precise point positioning (PPP) technique. Carrier-phase time transfer is first compared with two-way satellite time and frequency transfer (TWSTFT) between the same stations. It matches TWSTFT quite well and provides better short-term stability. Later, we extract 1-day data-arc boundary discontinuity jump values for 151 days. The distribution of jump values is almost Gaussian. Different GPS receivers have different mean jump values (-200ps-200ps) and different standard deviations (100ps-300ps). In addition, with the increase of data-arc from 1-day to 4-days, both mean value and deviation increase. For receivers at the same station, the correlation varies. This suggests that the boundary discontinuity does not mainly come from satellite-path related noise. Further investigation reveals that multipath also contributes little to boundary discontinuity. Comparison between PPP and network method shows that the algorithm of fixing phase ambiguity plays an important role in boundary discontinuity.
Proceedings Title: Proceedings of the 44th AnnualPTTI Systems and Applications Meeting
Conference Dates: November 26-29, 2012
Conference Location: Reston, VA
Pub Type: Conferences
boundary discontinuity, carrier-phase, GPS, precise point positioning, time transfer