[ntp:questions] National time standard differences

David J Taylor david-taylor at blueyonder.delete-this-bit.and-this-part.co.uk.invalid
Thu Feb 11 21:25:34 UTC 2010

> The flying clock tests were closed loop (I think there's a more accurate 
> term for the process) where the clock, including both its initial time 
> error and its frequency offset (rate difference from USNO or NIST), was 
> well characterized via radio and against a set of similar clocks prior 
> to take-off.  At the end of the trip, the clock was measured again.  The 
> time difference between departure and arrival was proportionally applied 
> to the measurements taken along the way.  e.g., if the clock was known 
> to be 10ns/day fast during the trip, you adjust a measurement made on 
> the 3rd day by 30ns.  There were lots of additional statistics applied 
> to improve the measurement results.
> John

Thanks, John.  Was the measurement down to the nanosecond level?


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