Evaluating Optical Clock Performance for GNSS Positioning.

Area of Science:

• Atomic, Molecular, and Optical Physics
• Geodesy and Geophysics
• Satellite Technology

Background:

• Atomic clocks are crucial for Positioning, Navigation, and Timing (PNT) systems, including Global Navigation Satellite Systems (GNSS).
• Emerging optical clock technology offers significantly higher precision than traditional atomic clocks, with uncertainties reaching 1 × 10^-18.

Purpose of the Study:

• To provide an overview of optical clock technology, its development, and characteristics.
• To analyze the stability of optical clocks against GNSS satellite atomic clocks.
• To discuss the potential of optical clocks in enhancing GNSS positioning accuracy.

Main Methods:

• Stability analysis of optical clocks using data from existing literature.
• Estimation of GNSS satellite clock stability using the Overlapping Allan Deviation (ADEV) method on International GNSS Service (IGS) clock products.
• Comparison of optical clock performance against Galileo satellite atomic clocks.

Main Results:

• Optical clocks demonstrate superior stability compared to atomic clocks currently used in GNSS satellites.
• Optical clocks have the potential to achieve less than 1 mm range error in GNSS positioning within 30 seconds.
• Optical clocks can provide at least 10 times better timing performance than Galileo atomic clocks after 900 seconds.

Conclusions:

• Optical clocks represent a significant advancement over atomic clocks for PNT applications, offering enhanced stability and precision.
• While promising, optical clock technology requires further development to meet the stringent requirements of spacecraft payloads.
• The integration of optical clocks into GNSS could revolutionize positioning accuracy and timing performance.