[time-nuts] Possible GPS Interference test

[Tim Shoppa]

I went ahead and did the math based on some of your numbers. I was a little
unclear on which numbers to use.

-2E-10 in frequency over 5 minutes, is -60ns. 60ns is not completely
unreasonable for an ionospheric delay variation over hours, but I think it
would be unusual for there to be so much tumult in just 5 minutes though.
(Especially when geophysical K index has been particularly calm lately.)

On the other hand, -2E-10 over 3 hours, is -2 microseconds which is just
huge!

Do you have anything like a graph of phase difference or EFC over those 3
hours?

Tim N3QE

On Wed, Sep 30, 2015 at 1:54 AM, James Flynn <james.flynn at csun.edu> wrote:

> I recorded apparent anomalous activity on the GPS signal received near Los
> Angeles from about 0200Z to 0500Z 30 Sept. The 1PPS received signal
> shifted by -2E-10 in frequency (5 minute averages).
>
> There is a notice on the GPS website about possible interference today (29
> Sept) through 30 Sept in the area of 253 nm around China Lake, CA. (which
> includes Los Angeles)
>
> Anyone else near LA notice anything?
>
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