[LEAPSECS] a big week for leaps at SG7 and WP7A

Steve Allen sla at ucolick.org
Mon Sep 29 23:58:49 EDT 2014


This is a big week for the leap second.

In Geneva the ITU-R SG7 meeting is tomorrow and the WP7A meeting
follows.  Titles of the WP7A contributions are visible at
http://www.itu.int/md/R12-WP7A.AR-C/en
http://www.itu.int/md/R12-WP7A-C/en
They show a document from Russia, from USA, and one from the recent
URSI meeting in Beijing which may be a resolution from URSI Comm A.

The report of the chairman from the May meeting of WP7A included
two documents which are aimed to be presented at WRC-15 next year.
http://www.itu.int/md/R12-WP7A-C-0056/en
One was a draft CPM document on WRC-15 Agenda Item 1.14 (about the
future of the international time scale), and the other was an earlier
draft of the US contribution for this week.  During its review period
the current US contribution was visible and it asserted that its
content should replace the draft CPM document.  Versions of the draft
CPM document that have been visible included three different methods
for resolving the leap second question posed in Agenda Item 1.14.
A: stop leaps, possibly changing the name
B: keep UTC with leaps and approve a leap-free time scale
C: keep UTC with leaps, document it clearly, and maybe do something else

The URSI document may be related in some way to the presentation by
Matsakis in Beijing
http://tycho.usno.navy.mil/papers/ts-2014/Matsakis-LeapSecondComments.URSI-2014.pdf

One thing that has not been contributed to the ITU-R is the result of
the IAU Working Group on the Redefinition of UTC.  They rushed to
prepare their report in time for the WP7A meeting earlier in the year,
but the IAU never forwarded it to the ITU-R.  The UTC WG report was
recently linked at the bottom of
http://www.iau.org/science/scientific_bodies/divisions/A/wgs/
in this URL
http://astro.geo.tu-dresden.de/4DIVA/ReportOfTheIauWorkingGroupOnCoordinatedUniversalTime2014.pdf
In large part the report covers the history of various IAU resolutions
which led to the inception of leap seconds, so it is strange that before
publishing the report the IAU prepended a disclaimer to the document.

--
Steve Allen                 <sla at ucolick.org>                WGS-84 (GPS)
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