Interferometric Fibre Links (A05)

• Subject Area: Geodesy, Photogrammetry, Remote Sensing, Geoinformatics, Cartography
• Term: since 2021
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 434617780

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. Measuring this apparent frequency difference between clocks, supposedly 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 fibres over large distances, between clocks at different locations, including remote locations like islands. By using the fibre links, also the frequency transfer with Global Navigation Satellite Systems will be advanced.

• DFG Programme: Collaborative Research Centres
• Subproject of: SFB 1464: Relativistic and quantum-based geodesy (TerraQ)
• Applicant Institution: Gottfried Wilhelm Leibniz Universität Hannover
• Co-Applicant Institution: Physikalisch-Technische Bundesanstalt (PTB)
• Project Heads: Dr. Gesine Grosche; Professor Dr.-Ing. Steffen Schön