[time-nuts] Rb-Thunderbolt test during a solar eclipse

[Azelio Boriani]

Remember the man with two clocks: here we are in the same situation. We
cannot tell which of the two is being screwed up or maybe both... this is
my opinion. Interesting experiment but I think it would be better if a
third clock was involved, for example a Cs reference.

On Mon, Sep 3, 2012 at 9:16 PM, iovane at inwind.it <iovane at inwind.it> wrote:

> Dear time-nuts,
> a friend of mine, Prof. Alexander Pugach (1), did an experiment on January
> 15,
> 2010, comparing a Rb standard to a GPSDO during a solar eclipse. The
> experimenal site was Kiev, Ukraine.
>
> With reference to the attached graph, his text is (note: the red curve
> belongs
> to another test; the curve which matters here is the bold blue one):
>
> ****************************
> Dear colleagues,
> An experiment has been made aiming to investigate, how the “daily rate of
> clock” varies during a solar eclipse on 01.15.2010.
> In our observatory the high-precision rubidic standard (RbSt) of frequency
> is
> exploited. Its indications were compared to a basic frequency from highly
> stable GPS receiver TRIMBLE Thunderbolt Е. The difference obtained is
> noted as
> “residue” and expressed in nanoseconds (ns).
> This residue was conventially set equal to 0 ns at 00h 00m 13.01.2010. The
> mean “daily rate of RbSt” equals  2740 ns/d, i.e.  3.17 10-11.  In the
> Figure
> this rate is shown with blue dashed line. What we have really registered is
> shown with the bold blue curve.
> The main minimum of this difference approximately coincided with the
> eclipse
> start on the Earth. The derivative on site А-В is approximately  6 times as
> much as mean “daily rate of RbSt”.
> ............
> 19.02.2010
> ****************************
>
> Apparently, the difference of rate of the two clocks varied by some 4000
> ns, A
> to B, in the 6 hours of duration of the eclipse (s to e = start to end of
> eclipse at earth, T1-T4 =eclipse in Kiev).
> I would ask you time-nuts, if such a variation could be simply due to an
> occasional sum of "ordinary" adverse factors such as temperature,
> holdover, sky
> view, multipath, etc.., or it is really too large to be explained that way.
> Sorry, I've no idea of what would be the worst case for any of the above
> factors.
>
> Thanks,
> Antonio I8IOV
>
> (1) Prof. Pugach is a senior astronomer at the Academy of Sciences of
> Ukraine.
>
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