[tz] [PROPOSED] Cite Rec. ITU-R TF.460-6 for leap seconds

[Steve Allen]

On Thu 2019-07-04T00:35:32-0700 Paul Eggert hath writ:
> Subject: [tz] [PROPOSED] Cite Rec. ITU-R TF.460-6 for leap seconds

In addition to the listed changes I suggest being more specific about
the meaning of UT1 in leapseconds.awk by defining what is meant by
"space".

>    print "# The International Earth Rotation and Reference Systems Service"
>    print "# periodically uses leap seconds to keep UTC to within 0.9 s of UT1"
>    print "# (which measures the true angular orientation of the earth in space)"

to

>    print "# The International Earth Rotation and Reference Systems Service"
>    print "# periodically uses leap seconds to keep UTC to within 0.9 s of UT1"
>    print "# (which is a measure of the angular orientation of the earth's crust"
>    print "# with respect to a reference frame designed to match Newcomb's"
>    print "# Tables of the Sun in Astronomical Papers Prepared for the Use of"
>    pring "# the American Ephemeris and Nautical Almanac, Volume VI, 1895)"

as is nicely explained with full references
https://en.wikipedia.org/wiki/Newcomb%27s_Tables_of_the_Sun

--
Steve Allen                    <sla at ucolick.org>              WGS-84 (GPS)
UCO/Lick Observatory--ISB 260  Natural Sciences II, Room 165  Lat  +36.99855
1156 High Street               Voice: +1 831 459 3046         Lng -122.06015
Santa Cruz, CA 95064           https://www.ucolick.org/~sla/  Hgt +250 m