[LEAPSECS] EFTF Discussion on Leap Seconds

From: Demetrios Matsakis <dnm_at_orion.usno.navy.mil>
Date: Tue, 13 Mar 2001 00:02:31 +0000

I have just returned from the 2001 European Time and Frequency Meeting,
where a short and informal session was held on the leap second issue.
There were perhaps 30 attendees, and it was chaired by Ron Beard, the
head of the ITU/R committee that will be making recommendations to the
main body of the ITU/R.

Ron said that letters from the ITU have been sent asking for cooperation
from other international bodies. He did not have the complete list of
recipients, but had learned that Daniel Gambis will head the
International Earth Rotation Service (IERS) effort. Dennis McCarthy of
the USNO will chair the International Astronomical Union (IAU)
committee, and I will also be on it.

Both Ron and Dennis are subscribers to this chat group, but will
probably not respond directly to any queries as they see their current
roles as to gather information rather than take sides. I also see my
role here as to be impartial, but will continue to supply any factual
information I can to this group.

At this meeting, several references were made to the BIPM's letter of
1999, which pointed out that users who could not tolerate leap seconds
should use International Atomic Time (TAI) as the alternative to UTC.
The planned European satellite system Galileo is due to get its final
funding decision this month, and it will run on TAI. In support of
TAI-users, NIST is planning to make TAI-UTC available in the format of
its WWV-series of broadcasts. It is already in their NTP format. NIST
first step will be a user-survey, to come out in a few months.

The USNO uses a more standard NTP format that at most tells you if a
leap second is coming, but we are working on the problem as well.
Judah Levine of NIST made a proposal at PTTI-00 to include the full
list of leap seconds in all NTP packets, but others suggested just
giving the current value plus a change-bit, or replacing the list with
a link to a Web page.

Demetrios Matsakis

P.S. to Rob Seaman: I have learned that the transcript of the PTTI
discussion are not yet ready. I will email them out as soon as I
get them. However, there are problems with the electronic version of
the paper by Chadsey and McCarthy. The PTTI proceedings should come
out in the summer.
Received on Mon Mar 12 2001 - 16:06:54 PST