[ncrs-general] Questionnaire on the Leap Second

[Phil Wilkinson]

Hello All,

FIRST: a brief reminder that early registration for WARS04
closes 12th December.  

Second: the Leap Second.

The message below commences with the URSI Secretariat's comments 
about the previous distribution of a questionnaire on the leap
second, which many of you may not have seen, followed by 
the questionnaire.  

If you have feelings about leap seconds and timing in general,
then please extract the questionnaire below and send your
responses back to: 

	Dr. Demetrios N. Matsakis
    	matsakis.demetrios at usno.navy.mil

Note the deadline: 1 January 2004 for responses.

-----------------------------------------------------------------
URSI Secretariat Comments
-----------------------------------------------------------------

Ladies and Gentlemen,

About one month ago Dr. Demetrios N. Matsakis, Chair of the URSI Working 
Group on the Leap Second, sent the message below to you.
Now it turns out that something may have gone wrong with that message...
We hereby re-send it and hope that many of you will respond in the very near 
future...
The ultimate deadline remains January 1, 2004. Please send your 
questionnaire or comments to Dr. Demetrios N. Matsakis 
<matsakis.demetrios at usno.navy.mil>.
With best regards,

Inge Heleu
URSI HQ
20 November 2003


*********************************************************************
		Dr. Matsakis message follows.
*********************************************************************

Dear URSI Colleague,

The URSI Secretariat has received a letter from the Special Rapporteur Group
of the International Telecommunication Union (ITU), whose charter is to
study and make recommendations on the redefinition of Coordinated Universal
Time (UTC), which differs from International Atomic Time (TAI) by the
insertion of leap seconds to account for the variable rotation of the Earth.
The letter invites URSI participation in their study, which has since been
narrowed to consideration of whether the current practice of inserting leap
seconds so as to keep |UT1-UTC|  < .9 seconds should be replaced by a policy
of inserting no leap seconds, so that UTC-TAI will remained at a fixed value
indefinitely.  This would affect systems that depend upon UT1 being close
enough to UTC that the difference can be ignored or that the format for
specifying the difference can have a fixed sized.   An analysis of the
motivation for a change was recent published in Metrologia, 2001, 38, pp.
509-529, a copy of which is attached.

Previous to the formation of the ITU Special Rapporteur Group, an URSI
Commission J Working Group was formed at the 1999 URSI General Assembly in
Toronto, Canada and their report is attached.  Subsequently, the 2002 URSI
General Assembly in Maastricht, The Netherlands formed an URSI Working Group
(WG) to study the effects of such a change upon systems relevant to URSI
radioscientists, and to propose a response to the ITU.    The resolution
creating the WG is attached.   The members of the WG are Demetrios Matsakis
(chair), Wim Brouw, Sigfrido Leschiutta, and Inoue Makoto, and their contact
information is also attached.  An informal listserv on the technical,
scientific, and political aspects of this matter can be accessed via
http://rom.usno.navy.mil/archives/leapsecs.html, and a broader summary is
being maintained by Markus Kuhn at
http://www.cl.cam.ac.uk/~mgk25/time/leap/.  Both of these sites provide an
excellent summary, by Markus Kuhn, of discussions and presentations at an
ITU-sponsored symposium on this subject, held in May 2003 at Torino, Italy.

In order to fulfill our charter, we have composed a questionnaire that we
would appreciate your assistance in distributing to all official members of
your commission.  This questionnaire will help us better understand their
needs.  While we do ask that the form of the questionnaire be followed, the
responders should feel free to use as much space to answer the questions as
required.

Please send the completed questionnaire to Matsakis.Demetrios at usno.navy.mil
by January 1, 2004.

Sincerely,



Dr. Demetrios Matsakis

Chair, URSI Working Group on the Leap Second

************************************************************************
************************************************************************
		Reply to this Questionnaire.
************************************************************************

Questionnaire on UTC Definition
please respond to matsakis.demetrios at usno.navy.mil by
January 1, 2004



1.      Name and Position

2.      Contact information

3.      URSI Commissions of specific interest to you

4.      Please provide the approximate cost to your systems, and your
systems' users, of incorporating the next leap second or any possible
deletion of a second.  If you feel the questions do not correctly
parameterize your system or its users systems, please indicate a better
formulation.   Please ignore inflation and assume exchange rates remain
constant.

a.      Name of System
b.      Brief Description of System
c.      Hours of labor
d.      Equipment purchase
e.      Costs in terms of final product or system performance if the leap
second or second-deletion is not correctly included
f.      Costs in terms of final product or system performance to incorporate
a leap second or second-deletion.
g.      Has your system or its users ever applied the leap second
incorrectly, and if so what percentage of the time?

5.      Note that one current plan under consideration would halt new leap
seconds after 2021.  If it were decided to change the definition of UTC so
that no leap seconds would be inserted after 2021, please provide the
approximate costs to your systems, and your systems's users, of adjusting
for such a change.    If you feel the questions do not correctly
parameterize your system or its users systems please indicate a better
formulation.  Please ignore inflation and assume exchange rates remain
constant.
a.      Name of System
b.      Brief Description of System
c.      Hours of Labor to make the adjustment
d.      Equipment Purchase to make the adjustment
e.      Costs in terms of final product or system performance if the
adjustment is not correctly made

6. If it were decided to halt new leap seconds after a specified date other
than 2021, is there an implementation date that would significantly affect
the costs indicated in your response to question 5?  If so, please provide
the associated costs in today's dollars, ignoring inflation.

7. Please use this space to make any comments or provide any information you
feel appropriate.

8. It is possible that we would like to publicly identify your system(s) or
your response as relevant to the decision.  In that case, do we have your
permission to fully quote your reply?


************************************************************************
		End of this Questionnaire.
************************************************************************
************************************************************************


best wishes,
Phil

--
Dr Phil Wilkinson, 
Chair, NCRS
Deputy Director
IPS Radio and Space Services 

_______________________________________________________
Department of Industry, Tourism and Resources
IPS Radio and Space Services   (ABN 51 835 430 479)
Street Address:  Level 6, 477 Pitt St., NSW 2000, AUSTRALIA
Postal Address:  P O Box 1386, Haymarket, NSW 1240, AUSTRALIA.
Ph: +61 2 9213 8003    Fax: +61 2 9213 8060 Email: phil at ips.gov.au
Internet http: //www.ips.gov.au/    IPS ftp region ftp.ips.gov.au

IMPORTANT: This e-mail, including any attachments, may contain
confidential or copyright information. The views expressed in 
this message are those of the individual sender unless specifically 
stated to be the views of IPS.  If you are not the intended recipient,
please contact the sender immediately and delete all copies of this 
e-mail and attachments.  The Commonwealth does not warrant that any
attachments are free from viruses or any other defects. You assume
all liability for any loss, damage or other consequences which may
arise from opening or using the attachments.