[time-nuts] December 6th? The mid-day Sun Spots blind the GPS

[Rob Kimberley]

There were significant solar flares during this period.
http://spaceflightnow.com/news/n0704/04gpssun/ is an interesting link. I
would suspect this is the cause.

Rob K

-----Original Message-----
From: time-nuts-bounces at febo.com [mailto:time-nuts-bounces at febo.com] On
Behalf Of Magnus Danielson
Sent: 13 April 2007 14:12
To: radcom at canada.com; time-nuts at febo.com; radcomtech at gmail.com
Subject: Re: [time-nuts] December 6th? The mid-day Sun Spots blind the GPS

From: "RadCom Technologies" <radcomtech at gmail.com>
Subject: [time-nuts] December 6th? The mid-day Sun Spots blind the GPS
Date: Fri, 13 Apr 2007 08:39:01 -0400
Message-ID: <c0fc4d530704130539p5924c8a8sdc275e864829b53a at mail.gmail.com>

> John Radisch asks the group (in general)
> 
> Had anyone observed any GPS outage of disturbance from December 6th 
> (2006) starting at about 3:45pm Eastern Time continuing through
> 
> mid-December, subsiding about December 13th-14th?
> 
> Any peculiar jumps in TIE or TDEV during this interval?
> 
> I refer to the global record breaking burst starting that day media 
> reports, our own client reports from western Canada and so on
> 
> My Colorado Springs Mil-Tech-friends say it did not effect SAASM's

We had a paging system failed since all their GPS receivers failed around
December 13th. They did not fail synchronously but within a day all failed.
All receivers continued to fail until replaced in Jan/Feb. We do _NOT_
suspect the sunburst activity (which wasn't THAT big) to cause these
failures.
Suspicion has been drawn towards other events. Also, we looked at the
magentometer values of ESRANGE in Kiruna (North of Sweden) and it had the
normal background levels prior to failures and some of the recievers failed
well in advance of the big magnetometer deviations. Not all sun-burts causes
issues with magnetometric values. We also checked the ionospheric deviations
(as measured using L1/L2 GPS and GLONASS receivers globaly) in that whole
period and no excess levels was actually detected.

Yes, sun-spot burst can cause some problems. You *do* have to check the
actual data and there is alot of publicly available measurements which you
can check with and correlate with.

IMHO you also need to consider software bugs and correlation to events in
GPS almanack and current view of constellation to see possible explanaition.

The GPS vendor claimed sunspots, but when confronted with other proofs, they
concluded that it _could_ be due to software issues. Sadly enought we have
not been able to finally conclude what happend. It is easy to say sun-spots,
there are certainly people advocating for that since it is a danger they
feel is not taken into account. While it *could* be sun-spots, there are
also several other things to consider. So look in wider circles, what is the
big picture saying.

We had a nation wide network fail at about that time. It has not been
consistently concluded to be either sun-spots or software, but we have
reasons to suspect the later. It still remains to be verified.

You will certainly see effects due to sun-spots when those deviations
occured.
I am interested in hearing about receivers that failed misserably in that
time-frame. It would be strange if it only affected one operator in one
country. These where old devices, but at least some time-nut should have one
of these operating. I know of one who has them, but not in current
operation.

Cheers,
Magnus

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