At 11:10 AM +0100 4/12/11, Ian Batten wrote:
On 12 Apr 11, at 0903, Poul-Henning Kamp wrote:
In message <[email protected]>,
Ian Batten wri
tes:
and thereafter contracts would add "times in
this contract shall be assumed to be UTC" to the definitions section.
Don't forget that a lot of obscure contracts with large technical
impact already states UTC explicitly: Air Traffic Control, AIS
Vessel tracking, telecoms accounting/settelment, NATO, meteology &c.
It will be interesting to find out if there are contracts which cite
UTC by name and which also assume that UTC is a close-enough measure
of angular position, rather than TAI+constant.
In ATC, the desire is to ensure that everybody use the same time, and
UTC is understood and distributed worldwide.
A good parallel is the altitude reported by transponders on aircraft.
What is reported is the pressure altitude assuming an atmosphere
without weather induced variations in atmospheric pressure. The
thinking is simple: If everybody translated pressure into altitude
the same way, vertical separation is ensured, as weather patterns
vary quite slowly with distance compared to required separations.
Nowdays we correct reported pressure altitudes for local atmospheric
pressure, to improve probability of correct correlation with radar
data.
Joe Gwinn
_______________________________________________
LEAPSECS mailing list
[email protected]
http://six.pairlist.net/mailman/listinfo/leapsecs
