[LEAPSECS] Schedule for success

[Poul-Henning Kamp]

In message <1230735418.495b883a0082e at webmail.unb.ca>, "Richard B. Langley" writes:

>Quoting Poul-Henning Kamp <phk at phk.freebsd.dk>:



>> So which datum is used for the zero meridian, which defines the UT* family

>> of timescales ?

>

>That would be the current ITRF as established by the IERS:

><http://www.iers.org/MainDisp.csl?pid=42-17>

>It is a realization of the ITRS:

><http://www.iers.org/MainDisp.csl?pid=97-108>


OK....

And since WGS84 is not rigidly linked to ITRS, doesn't that mean
that in order to use DUT1 broadcasts to point a telescope (precisely[1])
you also need to the ITRS/WGS84 difference at your place ?

Has anybody calculated what the worst case DUT1 difference is in
the WGS84 datum ?

Poul-Henning

[1] Yes, I know telescopes do not use dead reckoning at this level of 
precision (yet ?)

-- 
Poul-Henning Kamp       | UNIX since Zilog Zeus 3.20
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Never attribute to malice what can adequately be explained by incompetence.