[fitsbits] Leap Second questionnaire

[Rob Seaman]

This is another in a sequence of reminders to the FITS and ADASS
communities regarding a looming crisis in the UTC standard.

Over the last few years it has become increasingly obvious that an
initiative within the time and frequency community to revise UTC and
the rules for issuing leap seconds is really an initiative from some
subset of that community to eliminate leap seconds entirely.  The
motivation behind this remains somewhat unclear, but appears to
focus on the inability of certain projects (such as GLONASS, the
Russian version of GPS) to handle leap seconds gracefully.  The
reasoning is that the simplest way to "solve" this problem is to
get rid of leap seconds.

If it isn't obvious what that means - as it wasn't obvious to other
astro folks watching from the sidelines - that would mean that UTC
would be allowed to monotonically drift away from UT1 at a rate of
something over a couple of minutes over the next century.  In short,
civil time for the entire world would no longer be based on Greenwich
Mean Time and UTC would be "universal" in name only.  This seems like
an extremely poor idea on the face of it.  Over the centuries day
would literally turn into night - but this divergence would be
obvious to even casual amateur astronomers in just a few years.

Aside from the staggering change of perspective resulting from such
a situation, much astronomical software currently assumes that UTC is
an approximation to GMT and the cost in time and money of updating this
software would rival, if not dwarf, the expense of Y2K to the community.

I'm appending a questionnaire currently being circulated.  A large and
coherent response from the astronomical community - the astronomical
software community in particular - may help avoid a hasty decision
on this issue.  Silence would certainly not.

Rob Seaman
NOAO Science Data Systems (IRAF) Group
----------

Questionnaire regarding the use of UTC

Dear colleague

One month ago, we sent you a questionnaire concerning the use of UTC.
Thanks to users who already answered.

If you did not yet reply, we would like to remind you that the deadline
is 30 June 2002. In order to have a comprehensive view of the effects of a
possible change in UTC, I would like to stress that your answer is of prime
importance.

Thank you to take some minutes to fill the questionnaire and send it back
to the IERS Earth Orientation Center: iers at obspm.fr

Daniel Gambis
Head
Earth Orientation Center of IERS
Paris Observatory

===========================================================================
QUESTIONNAIRE

UTC (Coordinated Universal Time) is computed by occasionally adding leap
seconds to International Atomic Time (TAI). Since 1972, these leap seconds
have been added on December 31 or June 30, at the rate of about one every
18 months in order to maintain UTC close to UT1 within 1 second.

Some communities linked to telecommunication and navigational systems
have proposed a revision of the definition of UTC to avoid the
discontinuities due to intermittent leap seconds.

This survey is to know within Bulletins C and D users, what community
would be in favour of maintaining the present system or changing it.
I apologize if you get this questionnaire twice.


> Bulletin C    Announcement of the leap seconds in UTC.
> Bulletin D    Announcement of the value of DUT1 trncated at 0.1s to be
                transmitted with time signals.

The attached questionnaire is intended to know users interests and needs,
current and future. Put a cross for the selected answer [X].

                    Please send back this form
                    by 30 June 2002
                    to the IERS Earth Orientation Center: iers at obspm.fr

===========================================================================

1 - Who are you?
        Name:
        Institute:
        Adress:
        e-mail:

2 - Field of activity?
        Time                    [ ]
        Telecommunication       [ ]
        Astronomy/Astrophysics  [ ]
        Geophysics              [ ]
        Space sciences          [ ]
        Geodesy                 [ ]
        Navigation              [ ]
        Time laboratory         [ ]
        Other? What?            [ ]

3 -  Are you satisfied by the current UTC determination method with leap
     second adjustements?  YES or NO:
        YES                  [ ]
        NO                   [ ]


        3-1 if YES
        Is the present forecast time (6 months in advance)
        of the occurence of a leap second sufficient.
        YES                  [ ]
        NO                   [ ]

        If not would you suggest another time delay? 1 year or more?


        3-2 if NO
        Why ?

4 -  Do you think it would be better to change the determination method of UTC?

        YES                  [ ]
        NO                   [ ]
        NO IDEA              [ ]

  4 -1 If YES, which alternative solution would you favour?
  a. No leap second                       [ ]
    a.1 UTC without leap second           [ ]
    a.2 Use TAI                           [ ]
  b. Increase tolerance for |UT1-UTC|     [ ]
  c. Smooth over leap second step         [ ]
  d. Redefine the second                  [ ]
  e. Other possibility ?                  [ ]

  4-2 If NO for 4, why?

5 - Other assessment regarding determination or operation of UTC?

6 - This question addresses to Bulletin D users (DUT1 with .1s accuracy).
    Is the present Bulletin D convenient ?
        YES                  [ ]
        NO                   [ ]
        If NO, why?

        If NO, would you prefer a more frequent and refined estimation?
        With which accuracy?

           END OF THE QUESTIONNAIRE - THANK YOU FOR YOUR CONTRIBUTION