[LEAPSECS] New time scale name

p at 2038bug.com p at 2038bug.com
Fri Aug 13 07:44:35 EDT 2010




> If, for sake of discussion, we view TAI as correct, then according to HP

> Application Note 1289, The Science of Timekeeping, D. W. Allen, N. Ashby,

> and C. C. Hodge, the irregularities in the rotation of the earth are at

> the level of 1.5 × 10^-9 (page 20). Frequency transfer using HF radio

> broadcasts can be performed at the level of 10^-6 to 10^-8, and with LF

> radio broadcasts, the level is 10^-10 to 10^-11 (pg. 73). Currently, the

> FCC requires base stations for some public safety radios to have a

> frequency stability of 1^10-7 (47 CFR section 90.213) which radio

> technicians who do not necessarily have a university degree will have to

> be able to verify compliance to this level. So we see everyday needs and

> capabilities are bumping up against the fundamental frequency stability of

> UT1 right now. One supposes the requirements will only become tighter in

> the future. For several decades now, the frequency of the radio broadcasts

> has agreed with the time ticks (or at least, that is supposed to happen).

> If the ticks were instead providing UT1 while the carrier frequency

> continued to be calibrated to the SI second, this could cause widespread

> effects that have not been examined.

>


This is very interesting.

But I do notice the words "supposed to" and "could cause".

Would you be able to find out more about how these systems use these ticks
end-to-end?

Are these ticks currently synced to UTC? If so, then how? Or do they have
standalone clocks?

Who uses these ticks? For what? Do the systems that use it count time and do
they need that time to be in sync with other systems?

-paul


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