Re: [LEAPSECS] A lurker surfaces

From: Ashley Yakeley <ashley_at_SEMANTIC.ORG>
Date: Tue, 02 Jan 2007 15:21:14 -0800

Magnus Danielson wrote:
> The detailed introduction of the frequency
> corrections in various sources was different, and getting a coherent view of
> where UTC actually where was difficult. Since then we have grown to depend on
> UTC transmission to a higher degree than we did back then. Infact, for many
> purposes our UTC transmissions is also there to get us SI second traceability
> for a whole range of applications. If we brake the SI second in UTC a whole lot
> of technology will break. Rubber seconds would be a plain nightmare to
> introduce and maintain compared to the strange and slightly uncomforting dreams
> we have with the current leap second scheduling.

If the list will forgive me for airily focussing on the ideal rather
than the immediately practical... we should keep TAI and UTC as they
are, but create a new timescale for civil time with a new name and its
own separate infrastructure. Then we can persuade govenments to adopt
it. UTC can then fade into irrelevance.

> No, GPS is not TAI. GPS run its own timescale and it is offset from TAI by 19
> seconds, as given in BIPMs Circular T 227:

I meant up to a known conversion. If you have some GPS time, you know it
for TAI, and vice versa. That's not the case for UTC, since you don't
know what the leap second offset will be if it's too far in the future.
Of course you can also extract UTC from a GPS signal.

Ashley Yakeley
Received on Tue Jan 02 2007 - 15:21:33 PST

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