Time Transfer by Laser Link: The T2L2 experiment on Jason 2

The new generation of optical time transfer (T2L2 - Time Transfer by Laser Link) under development at OCA and CNES will allow the synchronization of remote ultra stable clocks and the determination of their performances over intercontinental distances. The principle is based on the propagation of light pulses between the clocks that are to be synchronized. T2L2 is the follow-on mission to LASSO (LAser Synchronization from Stationary Orbit) with performances improved by two orders of magnitude. Expected T2L2 performances are in the 100 ps range for accuracy, with an ultimate stability better than 1ps over 1,000s and than 10ps over one day. After a short overview of the instrumental heritage and the historic course of the project up to today's acceptation on Jason 2, we will report on a ground experiment conducted by OCA permitting to envision a performance improvement of at least one order of magnitude as compared to the best time transfer techniques available. Then preliminary performance budgets for the T2L2 on Jason 2 mission will be given, based on measurements conducted by OCA and expected performances of the space instrument. We will finish with the status of the space instrument development and a summary of recently conducted measurements of the electronics breadboards performances