Antonio M. Moreiras wrote: > The Cesium clock at observatorio nacional (ON) is UTC. In fact, the ON > is one of the metrology laboratories that colaborates with the Bureau > International des Poids et Measures (BIPM) in generating the UTC (as > NIST does in USA, for example). > > The Rubidium clocks are synchronized with the UTC at least one time per > year and the manufacturer says that the Rubidum reference has a monthly > aging less than 5e-11 and a yearly aging less than 5e-10. > > It gives us a 16ms maximum discrepancy from UTC (31,536,000,000 ms/year > * 5e-10 * 1 year = 15.765ms - is this correct?) > > After one year, with the discrepancy at 16ms it will be probabily of the > same order than the half round trip time for the majority of the clients. > > Given this, do you you think it will be necessary any modification?
Yes. An atomic clock with greater than 1 ms offset isn't really worth it's name. :-( In fact, with such a big slew rate, you would be much, much better off with a local GPS receiver to continually tune your Rb source. Terje -- - <[EMAIL PROTECTED]> "almost all programming can be viewed as an exercise in caching" _______________________________________________ questions mailing list [email protected] https://lists.ntp.org/mailman/listinfo/questions
