Time Transfer by Laser Link (T2L2) in Noncommon View Between Europe and China.

The Time Transfer by Laser Link (T2L2) project allows for the synchronization of remote ultrastable clocks over intercontinental distances. The principle is derived from the satellite laser ranging technology with a dedicated space equipment designed to record arrival times of laser pulses at the satellite. The space segment was launched in 2008 as a passenger instrument on the ocean altimetry satellite Jason 2.

Accuracy validation of T2L2 time transfer in co-location.

The Time Transfer by Laser Link (T2L2) experiment has been developed in close collaboration between Centre National d'Etudes Spatiales and Observatoire de la Côte d'Azur. The aim is to synchronize remote ultra-stable clocks over large-scale distances using two laser ranging stations. This ground to space time transfer has been derived from laser telemetry technology with dedicated space equipment designed to record arrival time of laser pulses on board the satellite.