[LEAPSECS] leapseconds, converting between GPS time (week, second) and UTC

[Steve Allen]

On Wed 2019-01-16T09:03:26+0000 Poul-Henning Kamp hath writ:
> In message <20190116085619.GA23164 at ucolick.org>, Steve Allen writes:
> >The epoch of TAI, and LORAN, and GPS is 1961-01-01T20:00:00 UT2.
> >Or maybe 1961-01-00 UT2.
> >
> >That is when the atomic time scale was set to a specified value.
>
> But the specific value they set was not zero in 1961-01-01T20:00:00 UT2,
> they set it so it would have been zero at 1958-01-01 00:00:00 GMT

Because of the reset at 1961 (and other ingredients in the sausage of
time) the difference between UT2 and TAI is not zero at 1958-01-01.
It is close to zero, but it is not zero.

One of the ingredients is that as of 1958-01-01 USNO was intentionally
using a longitude that differed by 0.035 time seconds from the
globally consistent value.

I also have not read closely enough to say whether those offset values
in the series H inception of A3 correspond to the values of UT2
before or after the longitudes of all stations changed on 1962-01-01.
The global average for that shift was 1.5 ms.

--
Steve Allen                    <sla at ucolick.org>              WGS-84 (GPS)
UCO/Lick Observatory--ISB 260  Natural Sciences II, Room 165  Lat  +36.99855
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