Clock Synchronization Experiment in India Using Symphonie Satellite
Y. V. Somayajulu, B.S. Mathur, P. Banerjee, S. C. Garg, Lakha Singh, P.C. Sood, Tuhi Ram Tyagi, C.L. Jain, Kuldeep Kumar · IETE Journal of Research · 1979
A recent clock synchronization experiment between the National Physical Laboratory (NPL), New Delhi and Space Applications Centre (SAC), Ahmedabad via geostationary satellite symphonie-II, stationed at 49°E longitude, is reported in this paper. As only one satellite transponder was available for this experiment, the two-way transmission of the clock pulses was carried out by switching the transmit—receive roles at the two stations at 5 minute intervals to achieve a nearly simultaneous two-way transmission. Taking into account all the additional delays, the results demonstrated a clock—synchronisation accuracy of better than 0.5 μs. A crystal-based portable clock flown aboard an aircraft confirmed this clock-synchronization to within a microsecond.