Coffee talks
Friday 15/05/2020 @ 11:30, On-line
Roberto Ricci (INRiM/INAF-IRA), "A geodetic VLBI experiment with the dissemination of a common clock via coherent optical fibre link"
Atomic clock synchronization plays an important role in both radio astronomical and geodetic Very Long Baseline Interferometry, as time and frequency standards are provided by station clocks. National metrological institutes have recently started streaming (via optical fiber links) frequency references from ultra-stable clocks based on optical line transitions in Strontium/Ytterbium laser-cooled lattices. Optical lattice clocks are already two order of magnitude more stable than the radio station H-masers. In this talk I will describe how the Italian Link for Frequency and Time (LIFT) works, the preliminary VLBI tests we performed with it and a European geodetic VLBI experiment in which the Medicina and Matera radio stations were connected via the LIFT link to the same remote clock located at the Italian Metrological institute in Turin. In a not-too-distant future a European VLBI network of radio stations could be connected via optical fiber links to a single very high-performance clock hosted by a European Metrological institute, the same way optical fibers now operate in eVLBI data transfer.