Politics of Redefining UTC

From: Demetrios <dnm_at_orion.usno.navy.mil>
Date: Thu, 6 Jul 2000 21:01:22 +0000 (UTC)

The actual decisions as to when a leap second will take place are made
by the International Earth Rotation Service (IERS), and based upon the
best available predictions of UT1-UTC.

The implementation guidelines followed by the IERS, and the authority of
the IERS, came from the International Consultative Committee for
Radiocommunications (CCIR). Therefore it is reasonable to assume that
the International Telecommunications Union (ITU), which is the
follow-on group to the CCIR, would be the body to decide if any change
should be made. While not bound by the rules of other scientific
organizations, they will be sensitive to the concerns of other
international agencies, such as the International Union of Radio
Scientists (URSI), the International Astronomical Union (IAU), the
Consultative Committee for Time and Frequency (CCTF), the International
Geophysical Union (IGU), and the IERS itself.

At this point, none of these agencies have taken a formal stand, however
in August of 1999, URSI Commission A (Electromagnetic Metrology) passed
a resolution in favor of a change, while URSI Commission J (Radio
Astronomy) began a study of the problem through the WG which I chaired.
Recently a committee of the Royal Astronomical Society (RAS) concluded
that there is insufficient justification for a change. The issue will
be brought up at the IAU General Assembly this August, and in some form
discussed at the ITU meeting in October. A special session on this
topic will be held at the November meeting of the Precise Time and Time
Interval (PTTI) Systems and Applications Meeting, details of which can
found below http://tycho.usno.navy.mil.

Demetrios Matsakis
July 6, 2000
Received on Thu Jul 06 2000 - 14:01:33 PDT

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