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Long-term comparisons between two-way satellite and geodetic time transfer systems
John F Plumb1, Kristine M Larson
1University of Colorado, Aerospace Engineering Sciences, Boulder, CO, USA.
Summary
Geodetic time transfer (GETT) using Global Positioning System (GPS) data shows precise timing capabilities. GETT performance was comparable to two-way satellite time and frequency transfer (TWSTFT) systems.
Area of Science:
- Geodesy
- Metrology
- Satellite Navigation
Background:
- Accurate time transfer is crucial for scientific and technological applications.
- Global Positioning System (GPS) and two-way satellite time and frequency transfer (TWSTFT) are established time transfer methods.
Purpose of the Study:
- To evaluate the time transfer performance of geodetic time transfer (GETT) using GPS observations.
- To compare GETT capabilities with existing TWSTFT systems.
Main Methods:
- Utilized GPS observations from the United States and Europe for GETT analysis.
- Compared GETT timing estimates with TWSTFT systems.
- Analyzed calibrated and uncalibrated time transfer links.
Main Results:
- A calibrated link at the U.S. Naval Observatory showed agreement of 2.17 ns over 6 months (0.73 ns standard deviation).
- An uncalibrated link between NIST and PTB exhibited a standard deviation of 0.79 ns over the same period.
Conclusions:
- GETT demonstrates high precision and reliability for time transfer applications.
- GPS-based GETT offers a competitive alternative to TWSTFT, particularly in terms of stability and accuracy.
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