[time-nuts] On Setting the Astronomical Time
Dr Bruce Griffiths
bruce.griffiths at xtra.co.nz
Sun Jun 10 17:14:54 EDT 2007
M. Warner Losh wrote:
> In message: <20070610173720.211CEBE20 at ip-64-139-1-69.sjc.megapath.net>
> Hal Murray <hmurray at megapathdsl.net> writes:
> : > Is there some way to get TT to better than a tenth of a second, or is
> : > the earth just too sloppy of a time keeper?
> : My guess...
> : The earth is sloppy on this scale. If it wasn't, we could predict leap
> : seconds.
> UT1 is a smoothed function, not an instantaneous one, since it factors
> out seasonal variation that's in UT2. NIST doesn't publish DUT1 more
> accurately than milliseconds with a +/- 5ms caveat. So +/- 100ms is
> "only" 20x worse than data published at nist.
Try subscribing to the IERTS prediction service, which will email
predictions of DUT1 at regular intervals.
Failing this just download their predictions.
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