نبذة مختصرة : The purpose of my Ph.D. works is the realization of a intercontinental time transfer,with a stability better than 2 ns over 10,000 s, between the International Laser RangingService (ILRS) geodetics observatories. This time transfer is performed thanks to optical spacelinks and the Time Transfer by Laser Link (T2L2) experiment. T2L2 is a passenger on-board theoceanographic satellite Jason-2, which was launched the 20th June 2008, at 1336 km of altitude.The principle of this experiment is based on the (two-way) short laser pulses (30 - 100 ps) timetagging, in laser station on ground and on-board the satellite, which come from 25 worldwidelaser stations. The high performance of the ground-to-space link (where the stability reach valuesbetter than 10 ps over 100 s), given by the laser technology in one hand, and the quality of thespace instrument in the other hand, allows to precisely read the frequency variations of the onboardoscillators (quartz) built for the orbitography and localization Doppler Orbitography andRadiopositionning Integrated by Satellite (DORIS) French system. We demonstrate the possibilityto build a deterministic frequency model, on the short term (10 days), mid-term (severalsmonth) for the on-board DORIS oscillator frequency evolution, with a relative precision at 3- 5·10≠13. Frequency variations are caused by a complex space environment, where radiations,temperature and device aging damage the oscillator. The integration of this model allows us tobuild an "on-orbit" time realization to synchronize the whole ILRS network and thus, estimatelaser station time biases in regard to the Universal Time Coordinate (UTC). The time bias effects,estimate thanks to T2L2, on the International Terrestrial Reference Frame (ITRF) stationcoordinates, is precisely determined at the level of a few millimeters. Finally, T2L2 is able totime tagged the Global Positionning System (GPS) Pulse Per Second (PPS) signal in order tostudy the clock long term (several years) behavior in laser station and we show the ...
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