Title :
Comparison of distant Cs-clock monitoring methods
Author :
Kalliomäki, K. ; Mansten, T.
Author_Institution :
Dept. of Electr. Eng., Oulu Univ., Finland
Abstract :
National Standards laboratory, VTT/AUT in Finland derives it time from four Cs-clocks: three Oscilloquarz 3210 and a HP 5071A. Oscilloquarz clocks are situated in a special access controlled subterranean facility. Clock phases are compared to HP 5071A and GPS-time using three different simultaneous remote measurement techniques. The methods are TV-frame sync. pulse measurement, GPS-second tick comparison and optical 2048 kHz synch. signal comparison. Thus annual delay variations and drift of remote measurement systems can be estimated. Short term stability is about the same for all those methods (30 ns), optical connection is the best. Long term stability is around 100 ns/year. All the methods suffers from phase jumps the origin of which is not clear in all cases
Keywords :
Global Positioning System; atomic clocks; measurement standards; optical communication; stability; telemetry; time measurement; 2048 kHz; Cs; Finland; GPS; HP 5071A; National Standards laboratory; Oscilloquarz 3210; TV-frame sync; VTT/AUT; access controlled subterranean facility; annual delay variations; distant Cs-clock monitoring; drift; long term stability; optical 2048 kHz sync signal; optical connection; phase jumps; remote measurement; short term stability; Clocks; Delay estimation; Frequency synchronization; Humidity; Laboratories; Monitoring; Optical receivers; Phase measurement; Pulse measurements; Stability;
Conference_Titel :
Frequency and Time Forum, 1999 and the IEEE International Frequency Control Symposium, 1999., Proceedings of the 1999 Joint Meeting of the European
Conference_Location :
Besancon
Print_ISBN :
0-7803-5400-1
DOI :
10.1109/FREQ.1999.840768
