Subject: [SLR-Mail] No. 1393: T2L2 On Jason2 From: Etienne Samain > ******************************************************************************** SLR Electronic Mail 2005-09-29 16:10:00 UTC Message No. 1393 ******************************************************************************** Author: Etienne Samain Subject: T2L2 On Jason2 The Time Transfer by Laser Link T2L2 project has recently been accepted by the French Space Agency CNES. T2L2 is proposed as a passenger instrument on board the Jason 2 satellite. The T2L2 experiment will allow the synchronization of remote clocks on Earth, and the monitoring of a clock on board the satellite. The principle is based on the propagation of light pulses, emitted by laser stations, between the clocks to be synchronized. Jason 2 is a follow-on mission to Jason 1 that will study the internal structure and dynamics of ocean currents. It will be placed by a Delta launcher in the same orbit as Jason-1 (66°,1,336 km). The objectives of the T2L2 mission are threefold. The first one is a technology objective around the validation of the optical time transfer. It includes the validation of the experiment, and the validation of the time stability and accuracy. The second one is for time and frequency metrology, fundamental physics and earth observation. The third one, correlated with Jason 2 objectives, includes the characterization of the on board Doris oscillator, specially above the South Atlantic anomaly, and one way telemetry. T2L2 will work with the Laser Ranging Array (LRA) that has already been used by Jason 1 (9 corner cubes having an aperture of 32 mm). The T2L2 instrumentation is divided in 2 packages: the first one (electronic) is located inside the satellite : 8kg, 300x300x150mm ; the second one (optics) is located near the LRA outside the satellite structure. The general specifications are: Wavelength 532 nm +/- 0.5 nm Minimum Energy per pulse : 10 mJ. Maximum rate: above 1 kHz The Jason 2 launch is scheduled in 2008 and the exploitation is envisioned for 5 years. It is important to emphasis that the succes of T2L2 depend greatly on the participation of the whole ILRS network. We are sure that the project can rely on the laser community. Best Regards The T2L2 crew From: Etienne Samain ********************************************************************************