[LEAPSECS] ITU-R SG7 to consider UTC on October 4

Rob Seaman seaman at noao.edu
Wed Aug 4 15:26:18 EDT 2010

On Aug 4, 2010, at 10:30 AM, Steve Allen wrote:

> According to the ITU-R the next meeting of SG7 will happen in Geneva

> on

> 2010-10-04 and 2010-10-12.

Makes one wonder what they'll do with the intercalary week in between...

> Timofeev has released a questionnaire to the delegations along with

> instructions that SG7 should only consider technical issues.

> Technical issues would mean the draft is to return to WP7A.

> Other-then-technical issues are to be referred to the

> Radiocommunication Assembly.

Proper system engineering practices do not artificially separate
requirements into technical versus other-than-technical bins. Some
technical requirements are non-quantitative. Many "other"
requirements are eminently quantitative. A trade-off requires
building figures-of-merit for all requirements and evaluating
different schemes for combining and contrasting the quantitative
scores and the sensitivity of different issues to various parameters.

By all means debate the issues - although does the Radiocommunication
Assembly have a broad enough mandate to appropriately address the
issues? However, don't pretend that only real engineers can properly
understand technical issues, while "other-than-technical" issues are
some mash-up of trivial politics.

> Do you support maintaining the current arrangement of linking UT1

> and UTC (to provide a celestial time reference)?

Yes. The current standard is viable for centuries, providing copious
time to discuss options outside the current politicized process.

> Do you have any technical difficulty in introducing leap second

> today?

No. The alternative would cause more trouble than it naively claims
to circumvent.

> Would you support the revision of Recommendation ITU-R TF.460-6?

No. And TF.460-6 doesn't resolve the underlying geophysical issue or
provide a future standards path to make the inevitable much larger and
more intrusive adjustments to civil timekeeping that will be needed.

> If it is agreed to eliminate leap second within 5 years after

> approval of the revision of Recommendation ITU-R TF.460-6, would

> that create technical difficulties for your administration?


> The US draft answers from USWP7A Chairman Wayne Hanson are


> no

> yes

> yes

> no

USWP7A clearly doesn't represent the interests of astronomers or of
general civil timekeeping.

Civil timekeeping is layered on mean solar time - a constant offset
from the underlying sidereal period. Pretending otherwise is naive.
Those professionals who need a timescale without leap seconds have
numerous options to choose from. Leave UTC alone. UTC without leap
seconds would no longer be a flavor of Universal Time.

Rob Seaman
National Optical Astronomy Observatory

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