[time-nuts] The National Labs and the nS.

Mike Fahmie mpfahmie at lbl.gov
Mon Mar 12 18:35:36 UTC 2007


>
>When you get to the sub-100 ns level UTC is not GPS. And
>UTC(NIST) isn't UTC(USNO). Even the national labs don't
>agree down to the last ns.
>
>/tvb

Remember that no one lab has the true UTC clock. UTC is an offset to Atomic 
Time (TAI), and TAI is the weighted average of hundreds of clocks in dozens 
of National Labs all over the world. The Bureau International des Poids et 
Mesures (BIPM  formerly BIH) collects data and publishes TAI, the 
International Earth Rotation Service (IERS), determine when Leap Seconds 
increment/decrement the offset based on variations of the earths rotational 
period.

See: http://www.bipm.fr/en/scientific/tai/tai.html for details!

-Mike-




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