Transnational time transfer via fibre-optics
Satellite navigation has transformed Europe’s transport services. The prospect of enhanced navigation applications has encouraged researchers to approach the technical limits: autonomous vehicle developers, for example, would value more precise and reliable data to deliver lane-level guidance. A solution could be to augment satellite signals with ground-based signals. Demonstrating the concept required sub-nanosecond timing accuracy, but no practical calibration method was available to keep the entire system in sync.
The EMRP NEAT-FT project showed that WR could be used to synchronise time signals to the nanosecond-level over large distances over dedicated fibre links.
The subsequent EMPIR TIMEFUNC project refined these methods to work in practical scenarios such where fibre networks were not terminated at the same location and for shared fibre networks. The networking hardware and service provider OPNT was also trained to calibrate WR networks.
Supported by the Netherlands Organisation for Scientific Research, the SuperGPS consortium developed a demonstrator testbed for its terrestrial positioning concept at The Green Village in Delft, calibrated by VSL to sub-nanosecond level using the method developed in TIMEFUNC.