[LEAPSECS] ITU-R SG7 to consider UTC on October 4
According to the ITU-R the next meeting of SG7 will happen in Geneva on 2010-10-04 and 2010-10-12. According to the US ITAC-R the issue of leap seconds in UTC will be considered by ITU-R SG7. The summary from V. Timofeev explains that last year ITU-R WP7A decided that they could not reach consensus and that they had addressed all the technical issues, so they advanced the proposed revision of Rec 460 to SG7. In the absence of approval from WP7A, SG7 could not approve, nor send it back to WP7A, so the draft has waited. 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. The 4 (technical) questions are Do you support maintaining the current arrangement of linking UT1 and UTC (to provide a celestial time reference)? Do you have any technical difficulty in introducing leap second today? Would you support the revision of Recommendation ITU-R TF.460-6? 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 The US SG7 will have a telecon on 2010-08-16. I expect that some of this content should appear at https://www.ussg7.org/default.aspx Other international delegations are presumably engaged in similar review processes. -- Steve Allen s...@ucolick.orgWGS-84 (GPS) UCO/Lick ObservatoryNatural Sciences II, Room 165Lat +36.99855 University of CaliforniaVoice: +1 831 459 3046 Lng -122.06015 Santa Cruz, CA 95064http://www.ucolick.org/~sla/ Hgt +250 m ___ LEAPSECS mailing list LEAPSECS@leapsecond.com http://six.pairlist.net/mailman/listinfo/leapsecs
Re: [LEAPSECS] ITU-R SG7 to consider UTC on October 4
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? Yes. 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 ___ LEAPSECS mailing list LEAPSECS@leapsecond.com http://six.pairlist.net/mailman/listinfo/leapsecs
