On Sun 2006-01-08T11:44:04 -0700, M. Warner Losh hath writ:
> How is it that UTC can be realized in realtime, but TAI isn't. I
> thought the difference between the two was an integral number of
> seconds, by definition. Is that understanding flawed?
I believe the claim would be that UTC(insert your national time
service here) is realized in real time. UTC(USNO) is the official
time of the US, and I suspect that there would be loss of face if
any agency charged with keeping a national time did not, in some
sense, proclaim autonomy. UTC(pick one) is, of course, directly
related to TAI(pick one).
TAI(anywhere) has no official status anywhere, except in the ex post
facto statistical sense that it contributes to TAI (unmodified, the
real thing from the BIPM).
In an official sense of operational time scales, it is not clear that
there really is anything such as UTC (plain old, unmodified) which
differs from TAI by an integral number of seconds. As an identifiable
entity, UTC (unmodified) may only exist within the text of ITU-R
TF.460
--
Steve Allen <sla_at_ucolick.org> WGS-84 (GPS)
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Received on Sun Jan 08 2006 - 12:56:54 PST