[LEAPSECS] UT1 via NTP

[Warner Losh]

On Mon, Mar 19, 2018 at 2:02 PM, Gary E. Miller <gem at rellim.com> wrote:

> Yo Hal!
>
> On Mon, 19 Mar 2018 12:41:46 -0700
> Hal Murray <hmurray at megapathdsl.net> wrote:
>
> > Perhaps we should setup a simple UDP server that responds with the
> > UT1-UTC offset.  The idea is that you can get a good UTC via GPS or
> > good local NTP servers.
>
> How about the client just downloads the daily UT1 to UTC correction
> data, then adjusts UTC(GPS)?
>
>     http://maia.usno.navy.mil/ser7/ser7.dat
>
> Here is a sample of this week's report:
>
>                               IERS Rapid Service
>               MJD      x    error     y    error   UT1-UTC   error
>                        "      "       "      "        s        s
>    18  3  9  58186 0.00803 .00009 0.36036 .00009  0.157823 0.000011
>    18  3 10  58187 0.00857 .00009 0.36159 .00009  0.157100 0.000006
>    18  3 11  58188 0.00974 .00009 0.36269 .00009  0.156399 0.000004
>    18  3 12  58189 0.01137 .00009 0.36401 .00009  0.155694 0.000003
>    18  3 13  58190 0.01283 .00009 0.36560 .00009  0.154949 0.000065
>    18  3 14  58191 0.01385 .00009 0.36737 .00009  0.154118 0.000065
>    18  3 15  58192 0.01450 .00009 0.36927 .00009  0.153196 0.000055
>
> Looks to me about a kinda sort maybe 1 micro second per day shift.
>

Should be closer to 1ms/day. And it is: the above is 4.6ms in 6 days or
770us/day.

Warner
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