Two-way time comparison with the satellite Symphonie

Cs atomic clocks at satellite ground stations in West Germany and France were employed in conducting time comparison studies with the aid of the satellite Symphonie. Other time comparison experiments conducted were based on a use of Loran-C and an employment of transported clocks. The investigation showed that random measurement uncertainties in the case of satellite time comparisons are only a few nanoseconds. Systematic measurement errors, on the other hand, related to inaccuracies in the determination of signal travel times, are in the range from 80 to 90 ns. Inaccuracies of about 150 ns were observed in time-comparison experiments involving the use of Loran-C. An evaluation of the accuracy of the satellite time comparison studies on the basis of Loran-C data was, therefore, not possible.