[LEAPSECS] LOD and gravity connected ?

Steve Allen sla at ucolick.org
Wed Apr 29 12:55:45 EDT 2015

On Wed 2015-04-29T09:28:45 -0600, Warner Losh hath writ:
> >   http://iopscience.iop.org/0295-5075/110/1/10002/article
>       The files extend from 1962 January 1, when the Consultative Committee on
>       International Radio (CCIR) established Universal Time Coordinated (UTC)
>       as the standard for time keeping, to the most current date available.
> I notice that this is one of the few un-footnoted facts presented in this paper.

That's a bit imprecise about exactly what happened as of 1962.
It wasn't because of UTC, a term which did not exist for 3 more years.

The boundary of 1962 on the IERS data exists because 1962-01-01 was
agreed as the date that

1) BIH changed from reducing the input observations with FK3 to FK4
   in accord with Resolution 59 from the 10th IAU GA.
2) BIH assumed responsibility for the coordination of UT in keeping
   with resolutions from URSI in 1960 September and IAU Comm 31
   in 1961 August
3) IAU Comm 31 directed BIH to determine new, globally self-consistent
   values for the longitudes of the observing stations to replace the
   longstanding "conventional longitudes" that had been in use

The BIH was woefully underfunded and I suspect that they could not
consider re-reducing the older observations to the newer system.
Everyone just had to hope that any shifts/discontinuities due to
the change of techniques and models were inconsequentially small.

Steve Allen                 <sla at ucolick.org>               WGS-84 (GPS)
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