Atomic Clocks for Geodesy

Abstract

We review experimental progress on optical atomic clocks and frequency transfer, and consider the prospects of using these technologies for geodetic measurements. Today, optical atomic frequency standards have reached relative frequency inaccuracies below 10-17, opening new fields of fundamental and applied research. The dependence of atomic frequencies on the gravitational potential makes atomic clocks ideal candidates for the search for deviations in the predictions of Einstein's general relativity, tests of modern unifying theories and the development of new gravity field sensors. In this review, we introduce the concepts of optical atomic clocks and present the status of international clock development and comparison. Besides further improvement in stability and accuracy of today's best clocks, a large effort is put into increasing the reliability and technological readiness for applications outside of specialized laboratories with compact, portable devices. With relative frequency uncertainties of 10-18, comparisons of optical frequency standards are foreseen to contribute together with satellite and terrestrial data to the precise determination of fundamental height reference systems in geodesy with a resolution at the cm-level. The long-term stability of atomic standards will deliver excellent long-term height references for geodetic measurements and for the modelling and understanding of our Earth.

73 pages, 22 figures

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Cited by in corpus (83)

• 20 years of developments in optical frequency comb technology and applications
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• 113 km Free-Space Time-Frequency Dissemination at the 19th Decimal Instability
• An Optical Atomic Clock Based on a Highly Charged Ion
• A quantum network of entangled optical atomic clocks
• Long-lived Bell states in an array of optical clock qubits
• Quantum Variational Optimization of Ramsey Interferometry and Atomic Clocks
• Quantum-limited optical time transfer for future geosynchronous links
• Femtosecond Synchronization of Optical Clocks Off of a Flying Quadcopter
• Point-to-Point Stabilised Optical Frequency Transfer with Active Optics
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• Heisenberg-limited noisy atomic clock using a hybrid coherent and squeezed states protocol
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• Prospects and challenges for squeezing-enhanced optical atomic clocks
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• Progress on Optical Clock Technology for Operational Timescales
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• Superradiant active optical atomic clocks: motivations and current challenges
• Potentials for general-relativistic geodesy
• Measurement of the Differential Static Scalar Polarizability of the ${}^{88}$Sr${}^{+}$ Clock Transition
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• Endcap-Type Paul Trap for Precision Spectroscopy and Studies of Controlled Interactions
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• Unification of global height system at centimeter level using precise frequency signal links
• Gravity field modeling using space frequency signal transfer technique between satellites
• Low-frequency fiber-optic vibration sensing with a Floquet-engineered optical lattice clock
• Preliminary experimental results of determining the geopotential difference between two synchronized portable hydrogen clocks at different locations