[time-nuts] Loran-C & French Clocks
Arnold.Tibus at gmx.de
Tue Mar 17 12:58:15 UTC 2009
UTC? France? Of course they do accept it! see :
Université de Technologie de Compiègne (UTC)
[ ;-) ]
We do use in Europe, including France, CET ¡
Central European Time, Time zone offset: UTC + 1 hour.
The GPS navigation system has GPS Time as its basis. Galileo
will have TAI as its basis. GLONASS has UTC as its basis,
Air traffic controllers are using UTC.
(Astronomical Times) we do find:
[...]There are two widely used time standards. One is the
of the earth, and the other is the frequency of atomic
(mainly the cesium-133 atom). [...]
[...] By definition, UTC and TAI have the same rate, but UTC
stays close to Mean Solar Time by adding integer numbers of
seconds, called leap seconds, from time to time. This keeps
solar noon at the same UTC (averaged over the year), even
though the rotation of the earth is slowing down. [...]
TAI is controlled from France since 1955 I think.
(Temps Atomique International) Location:
Bureau International des Poids et Mesures (BIPM), Sevres,
There is a discussion ongoing since years to find a new
for UTC for several reasons:
UTC Timescale Colloquium 28-29 May 2003
[...] As a matter of policy, the U.S. Naval Observatory
timescale, UTC(USNO), and its real-time implementation, Master
Clock #2 (MC #2), are kept within a close but unspecified
tolerance of the international atomic timescale published by the
Bureau International des Poids et Mesures (International Bureau
of Weights and Measures [BIPM]) in Sevres, France. The world's
timing centers, including USNO, submit their clock measurements
to BIPM, which then uses them to compute a free-running
(unsteered) mean timescale (Echelle Atomique Libre [EAL]). BIPM
then applies frequency corrections ("steers") to EAL, based on
measurements from primary frequency standards and intended to
keep the International System's basic unit of time, the second,
[...] The difference between UTC (computed by BIPM) and any
other timing center's UTC only becomes known after computation
and dissemination of UTC, which occurs about two weeks after the
fact. This difference is presently limited mainly by the
long-term frequency instability of UTC. UTC(USNO) has been kept
within 26 nanoseconds of UTC during the past year through
frequency steering of our Master Clocks to our extrapolation of
UTC. Since synchronization is never perfect, we provide the
latest data below on the differences between UTC and the UTC of
other timing centers, including USNO,
I therefore cannot see any problem is with France,
but we have the need to define more precise and stable
reference time from where we can then measure and add
the Earth and Solar instabilities for our daily used standard
watches, in order to be enabled still to continue living and
travelling sun synchronously....
I hope not having been informed wrong so far,
kind regards and always precise time
On Mon, 16 Mar 2009 18:32:56 -0500, Bill Hawkins wrote:
>According to Wikipedia (a handy way to avoid speculation), international
>agreement was reached in 1960.
>UTC is a compromise between the French and British initials.
>From: Rich and Marcia Putz
>Sent: Monday, March 16, 2009 5:55 PM
>Gov't got to save that money for executive bonuses!
>Also, would anyone like to speculate when France finally accepted UTC?
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