Sorry if this is a repeat, but I was logging GPS signal strength at the
time and noticed a significant dip at the time reported.  There's a plot
at http://www.febo.com/pages/gps_anomaly.  This was the only event of
this type in about a year's worth of data.

John

RadCom Technologies wrote:

From: "RadCom Technologies" radcomtech@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@mail.gmail.com

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

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

From: "RadCom Technologies" radcomtech@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@mail.gmail.com

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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time-nuts@febo.com
https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts

I have all the data on Dec 5-6th CME event.

Agreed on all excellent points.
**
Including Software flaws- I am very familiar
with software flaws and TRAIM errors;
although that has nothing to do with my Employer
or the Oscilloquartz Timing Products.

However, recheck your data for Dec 6th;
dont dismiss this CME ; it was very large.
In fact, this side of the globe picked up one h*ll of a sun-flare;
9 times larger than previous spikes, and in a low-cycle year too.
(at first I thought the April 4th media story was a April Fools or hoax- its
not)

=> Does anyone have TIE data for Dec 5~6th to about the 14th?
interval of MJDates of (24)54075.8 to about (24)54083 or so?
=>  Can you share TIE data with me? Does that TIE show much walk?

Johnny

On 4/13/07, Magnus Danielson cfmd@bredband.net wrote: