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Characterizing Periodic Variations of Atomic Frequency Standards via Their Frequency Stability Estimates
Weiwei Cheng1,2, Guigen Nie2,3,4, Jian Zhu1
1School of Transportation, Civil Engineering and Architecture, Foshan University, Foshan 528000, China.
Sensors (Basel, Switzerland)
|June 10, 2023
Summary
This study introduces a new method to accurately analyze periodic variations in atomic frequency standards (AFS) for Global Navigation Satellite System (GNSS) satellites. The approach improves the precision of satellite clock bias prediction.
Area of Science:
- Geodesy and Satellite Navigation
- Metrology and Timekeeping
Background:
- Atomic frequency standards (AFS) are vital for Global Navigation Satellite System (GNSS) satellite accuracy.
- Periodic variations and non-stationary random processes in AFS signals complicate clock data analysis.
Purpose of the Study:
- To develop a precise method for characterizing periodic variations in onboard AFS signals.
- To improve the accuracy of satellite clock bias prediction by addressing signal non-stationarities.
Main Methods:
- Utilized Allan and Hadamard variances to characterize periodic variations in AFS signals.
- Tested the proposed model against simulated and real satellite clock data.
- Compared the proposed method with traditional least squares techniques.
Main Results:
- Demonstrated that Allan and Hadamard variances of periodic components are independent of stochastic variances.
- Showed the proposed method offers more precise characterization of periodic variations than least squares.
- Confirmed that overfitting periodic variations enhances GPS clock bias prediction precision.
Conclusions:
- The developed variance-based approach accurately characterizes periodic variations in satellite AFS.
- This improved characterization leads to more precise prediction of satellite clock bias, crucial for GNSS performance.
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