Toruń Centre for Astronomy
Nicolaus Copernicus University

Fibre-optic delivery of time and frequency to VLBI station

Krehlik P., Buczek Ł., Kołodziej J., Lipiński M., Śliwczyński Ł., Nawrocki J., Nogaś P., Marecki A., Pazderski E., Ablewski P., and 11 co-authors

The quality of Very Long Baseline Interferometry (VLBI) radio observations predominantly relies on precise and ultra-stable time and frequency (T&F) standards, usually hydrogen masers (HM), maintained locally at each VLBI station. Here, we present an operational solution in which the VLBI observations are routinely carried out without use of a local HM, but using remote synchronization via a stabilized, long-distance fibre-optic link. The T&F reference signals, traceable to international atomic timescale (TAI), are delivered to the VLBI station from a dedicated timekeeping laboratory. Moreover, we describe a proof-of-concept experiment where the VLBI station is synchronized to a remote strontium optical lattice clock during the observation.

Astrophysics - Instrumentation And Methods For Astrophysics