Who uses DUT1?

From: Tom Van Baak <tvb_at_LEAPSECOND.COM>
Date: Sat, 30 Jul 2005 10:18:42 -0700

WWV and WWVB and perhaps other national
systems transmit DUT1 as a 3- or 4-bit signed
number of 100 ms. I'm curious what sort of
instruments or operational systems use or used
this value? Several astronomers on the list make
a good case that they depend on UTC being
close enough to UT1 for their work.

So my question is - is the actual value of DUT1,
as broadcast with single digit precision, still
used? And if so, from where do they get the
value? It's hard for me to imagine they would
get it from WWV/WWVB; reception is not always
good and these signals are not available outside
the US; astronomy is an international effort.

Outside the parts the world with LF timecodes,
neither cellphones nor GPS transmit DUT1 so
it makes me wonder if anyone uses it? I'm not
looking for an argument; just wondered if there
are photos or anecdotes of equipment that uses

It seems that if someone wanted DUT1 for an
application these days it would be far easier to
get it off the web. The internet is available in far
more places in the world than an LF timecode.
In addition, if one fetched it from IERS you'd get
DUT1 to 10 us resolution instead of 100 ms, and
past as well as future predictions.

Received on Sat Jul 30 2005 - 10:20:15 PDT

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