title: Long-term comparisons between two-way satellite and geodetic time transfer systems.
abstract: Global Positioning System (GPS) observations recorded in the United States and Europe were used to evaluate time transfer capabilities of GETT (geodetic time transfer). Timing estimates were compared with two-way satellite time and frequency transfer (TWSTFT) systems. A comparison of calibrated links at the U.S. Naval Observatory, Washington, D.C., and Colorado Springs, CO, yielded agreement of 2.17 ns over 6 months with a standard deviation of 0.73 ns. An uncalibrated link between the National Institute of Standards and Technology (NIST) and Physikalisch-Technische Bundesanstalt, Braunschweig, Germany, has a standard deviation of 0.79 ns over the same time period.
authors.affiliation: University of Colorado, Aerospace Engineering Sciences, Boulder, CO, USA.
authors.forename: John F
authors.initials: JF
authors.lastname: Plumb
authors.forename: Kristine M
authors.initials: KM
authors.lastname: Larson