[fitsbits] Future of UTC

[Rob Seaman]

Clive Page replies to my message:

>> 3) If astronomers have no control over the current process, why should
>>    we assume they will have any more control over whatever process is
>>    substituted?

> Well if UTC were redefined to be the same as TAI (but for an offset fixed
> for all time, or at least for a few thousand years until the next
> leap-hour ;-) then there would be no problem, no matter how the ground
> stations were operated.

...other than the fact that the pointing software for the groundstation
undoubtedly relies on a knowledge of UT1.  A prerequisite to processing
your signals is detecting them.

Yes, all the software in the world that currently steers telescopes and
ground stations could indeed be rewritten to rely on tabular Chebyshev
coefficients or some such, rather than closed form approximations, to
perform even the most pedestrian utility operation.  Are you confident
that all these systems will be updated properly?  One might imagine that
some facilities will simply close in preference to identifying funding to
update systems that were not previously broken and could have operated
indefinitely.  There is also the new implicit requirement that all
tracking and astronomical facilities now be connected to a network in
some fashion.

The bottom line is that the world community is nowhere near having
characterized all the systematic dependencies on the current UTC system
or the implications of replacing UTC with this bastardized standard.
It is absurdly premature to be considering a policy change - and it is
very inobvious that the "ITU-R", an organization that few will have heard
of before, is the keeper of UTC rather than, for instance, the IAU.

Read the ITU-R standard - the assumption drips from the pages that
UTC is an approximation to GMT.  I might agree that the ITU-R has
stewardship over how to convey that standard.  I would dispute that
replacing leap seconds with leap hours represents responsible
stewardship.

Rob Seaman
National Optical Astronomy Observatory