Femtosecond Optical Two-Way Time-Frequency Transfer in the Presence of Motion

Abstract

Platform motion poses significant challenges to high-precision optical time and frequency transfer. We give a detailed description of these challenges and their solutions in comb-based optical two-way time and frequency transfer (O-TWTFT). Specifically, we discuss the breakdown in reciprocity due to relativity and due to asynchronous sampling, the impact of optical and electrical dispersion, and velocity-dependent transceiver calibration. We present a detailed derivation of the equations governing comb-based O-TWTFT in the presence of motion. We describe the implementation of real-time signal processing algorithms based on these equations and demonstrate active synchronization of two sites over turbulent air paths to below a femtosecond time deviation despite effective velocities of +/-25 m/s, which is the maximum achievable with our physical setup. With the implementation of the time transfer equation derived here, we find no velocity-dependent bias between the synchronized clocks to within at two-sigma statistical uncertainty of 330 attoseconds.

References in corpus (11)

• Geodesy and metrology with a transportable optical clock
• A clock network for geodesy and fundamental science
• Optical two-way time and frequency transfer over free space
• Real-time geopotentiometry with synchronously linked optical lattice clocks
• Test of special relativity using a fiber network of optical clocks
• Synchronization of Distant Optical Clocks at the Femtosecond Level
• Frequency transfer via a two-way optical phase comparison on a multiplexed fiber network
• First international comparison of fountain primary frequency standards via a long distance optical fiber link
• Measurement of the impact of turbulence anisoplanatism on precision free-space optical time transfer
• Synchronous multi-color laser network with daily sub-femtosecond timing drift
• Reflection of light from a moving mirror: derivation of the relativistic Doppler formula without Lorentz transformations

Cited by in corpus (8)

• Femtosecond Synchronization of Optical Clocks Off of a Flying Quadcopter
• Point-to-Point Stabilised Optical Frequency Transfer with Active Optics
• Wireless Picosecond Time Synchronization for Distributed Antenna Arrays
• GENESIS: Co-location of Geodetic Techniques in Space
• Measurement of the impact of turbulence anisoplanatism on precision free-space optical time transfer
• Optical Atomic Clock Comparison through Turbulent Air
• Classical and Quantum Frequency Combs for Satellite-based Clock Synchronization
• Demonstration of Real-Time Precision Optical Time Synchronization in a True Three-Node Architecture