Frequency transfer through long-distance optical fibre links for relativistic geodesy (A04)

• Subject Area: Optics, Quantum Optics and Physics of Atoms, Molecules and Plasmas ; Geodesy, Photogrammetry, Remote Sensing, Geoinformatics, Cartography
• Term: from 2014 to 2019
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 239994235

As predicted by Einstein’s general theory of relativity, electromagnetic radiation experiences a frequency shift when travelling through a gravitational field, known as gravitational red shift. As proposed by Vermeer in 1983, and Bjerhammar in 1985, measuring this apparent frequency difference between clocks thus allows us to determine potential (or height) differences between remote sites. The goal of this project is to realise “chronometric levelling” by transferring optical frequencies via optical fibre over large distances, between clocks at different locations. This effort may support future unification of worldwide height reference grids.

• DFG Programme: Collaborative Research Centres
• Subproject of: SFB 1128: Relativistic Geodesy and Gravimetry with Quantum Sensors - Modelling, Geo-Metrology and Future Technology (geo-Q)
• Applicant Institution: Gottfried Wilhelm Leibniz Universität Hannover
• Project Heads: Dr. Gesine Grosche; Dr. Harald Schnatz