Title :
Earth station errors in two-way time transfer
Author :
Ascarrunz, F.G. ; Jefferts, S.R. ; Parker, Thomas E.
Author_Institution :
Time & Frequency Div., Nat. Inst. of Stand. & Technol., Boulder, CO, USA
Abstract :
We have investigated the earth station errors in two-way time transfer. A 3.7 m earth station and a very small aperture terminal (VSAT) earth station were used in these experiments along with a transponder located on a mountain about 10 km away. The temperature coefficient of the receive (RX) delay for the 3.7 m NIST earth station was found to be -150 ±30 ps/°C and the temperature coefficient for the transmit (TX) delay was -50±10 ps/°C. The overall temperature coefficient for the earth station was 100±30 ps/°C. Aside from environmental errors there are apparent changes in delay due to characteristics of the modulation/demodulation scheme. Apparent delay changes due to non-linearity effects in the earth station were as high as 10 ns. The errors due to code dependence and third code interference were as high as 3 ns
Keywords :
delays; electric distortion; errors; measurement standards; satellite ground stations; spread spectrum communication; time measurement; 10 ns; 3 ns; 3.7 m; NIST earth station; VSAT earth station; code dependence; earth station errors; environmental errors; modulation/demodulation scheme; nonlinearity effects; receive delay; temperature coefficient; third code interference; transmit delay; two-way time transfer; very small aperture terminal; Apertures; Clocks; Delay effects; Demodulation; Frequency conversion; Frequency estimation; NIST; Satellite ground stations; Temperature dependence; Transponders;
Conference_Titel :
Frequency Control Symposium, 1996. 50th., Proceedings of the 1996 IEEE International.
Conference_Location :
Honolulu, HI
Print_ISBN :
0-7803-3309-8
DOI :
10.1109/FREQ.1996.560310
