Solar storms spell trouble for GPS

Larry Dighera wrote:
http://www.newscientisttech.com/chan...e-for-gps.html
Solar storms spell trouble for GPS

SOLAR flares can drown out GPS signals with potentially serious
consequences for airlines, emergency services, and anyone relying on
satellite navigation.
....
How was such a clash missed? Because GPS receivers only became common
during a period of low solar activity. By 2011 solar flares will reach
the peak of their cycle and receivers will likely fail. ...

Of course this newsgroup was alive and well during the last solar
maximum and there were no widespread failures reported. Sam kept us
informed with the bulletins on current solar activity, but I noticed
only minor effects on my consumer-level GPS receivers. I still have
the tracklogs recorded in 2000 during the maximum and they don't
support the dire predictions of the above article.

FWIW, the last solar maximum occured around 2001, and GPS was in common
use then; I know I was using mine on a pretty regular basis then.

I don't recall any widespread disruptions. Not even slimspread
disruptions. :)

I'm thinking this may be much ado about nothing.

--Walt
Bozeman, Montana


Larry Dighera wrote:
http://www.newscientisttech.com/chan...e-for-gps.html
Solar storms spell trouble for GPS

SOLAR flares can drown out GPS signals with potentially serious
consequences for airlines, emergency services, and anyone relying on
satellite navigation.

It turns out these bursts of charged particles, which produce auroras
and geomagnetic storms, also generate radio waves in the 1.2 and
1.6-gigahertz bands used by GPS.

How was such a clash missed? Because GPS receivers only became common
during a period of low solar activity. By 2011 solar flares will reach
the peak of their cycle and receivers will likely fail. Or so
Alessandro Cerruti of Cornell University, New York, told a meeting of
the Institute of Navigation in Fort Worth, Texas, last week. The only
solution would be to redesign GPS receivers or satellites, which may
not be practical, says Cerruti.

From issue 2572 of New Scientist magazine, 07 October 2006, page 27

On Wed, 25 Oct 2006 06:44:32 -0700, Ron Wanttaja
wrote in
:

On Wed, 25 Oct 2006 11:12:07 GMT, Larry Dighera wrote:

How was such a clash missed? Because GPS receivers only became common
during a period of low solar activity. By 2011 solar flares will reach
the peak of their cycle and receivers will likely fail.

The sun is on an 11-year cycle. If 2011 is the date of the max (and we are
apparently in the minimum now), the LAST max was about 2000.

Of course, natural phenomena can be somewhat erratic, but you astute
analysis seems relatively consistent with International Space
Environment Service observations/projections:
http://www.sec.noaa.gov/SolarCycle/

Unless the author believes that GPS receivers only became common after
2000, the user community has already been through one solar max period.

Apparently it was Alessandro Cerruti of Cornell University who raised
the concern, not the New Scientist author. But, you are correct about
having used GPS during the 2000 - 2003 peak period. I don't recall
any anomalous GPS behavior back then, but I do recall a solar storm
that caused my garage door opener to spontaneously open and close the
door repeatedly one day.

On 25 Oct 2006 06:54:19 -0700, "peter" wrote in
.com:

I still have
the tracklogs recorded in 2000 during the maximum and they don't
support the dire predictions of the above article.

Agreed. But I did notice other radio controlled devices
malfunctioning.

"Walt" wrote in message
oups.com...
FWIW, the last solar maximum occured around 2001, and GPS was in common
use then;


This is actually all global warming is. Hot spots in the sun.
Im not worried.


I don't recall any widespread disruptions. Not even slimspread
disruptions. :)

I'm thinking this may be much ado about nothing.

--Walt
Bozeman, Montana


Larry Dighera wrote:
http://www.newscientisttech.com/chan...e-for-gps.html
Solar storms spell trouble for GPS

SOLAR flares can drown out GPS signals with potentially serious
consequences for airlines, emergency services, and anyone relying on
satellite navigation.

It turns out these bursts of charged particles, which produce auroras
and geomagnetic storms, also generate radio waves in the 1.2 and
1.6-gigahertz bands used by GPS.

How was such a clash missed? Because GPS receivers only became common
during a period of low solar activity. By 2011 solar flares will reach
the peak of their cycle and receivers will likely fail. Or so
Alessandro Cerruti of Cornell University, New York, told a meeting of
the Institute of Navigation in Fort Worth, Texas, last week. The only
solution would be to redesign GPS receivers or satellites, which may
not be practical, says Cerruti.

From issue 2572 of New Scientist magazine, 07 October 2006, page 27

On 25 Oct 2006 07:00:43 -0700, "Walt" wrote in
.com:


FWIW, the last solar maximum occured around 2001, and GPS was in common
use then; I know I was using mine on a pretty regular basis then.

I don't recall any widespread disruptions. Not even slimspread
disruptions. :)

I'm thinking this may be much ado about nothing.

Perhaps you might bring this up with Professor Paul Kintner
): http://people.ece.cornell.edu/paul/

Here's some more information:

http://www.news.cornell.edu/stories/...es.gps.TO.html
Sept. 26, 2006
Solar flares cause GPS failures, possibly devastating for jets and
distress calls, Cornell researchers warn.
Alessandro Cerruti of Cornell University, New York



http://www.ion.org/meetings/gnss2006...D&session=3#p5
Observed GPS and WAAS Signal-to-Noise Degradation Due to Solar Radio
Bursts
A. Cerruti, Cornell University

GPS signals, systems, and navigation accuracy are vulnerable to a
variety of space weather effects that are caused mostly by the
ionosphere. However, the sun, which is sometimes a strong radio
source, is the cause of GPS signal interference presented here. The
first direct observations of GPS L1 (1.57542 GHz) signal-to-noise
ratio degradation on two different models of GPS receivers due to the
solar radio burst associated with the 7 September 2005 solar flare are
presented.

Signal-to-noise ratio data from three identical, collocated receivers
at Arecibo Observatory and also from four identical receivers of a
different model located in Brazil, were available at the time of the
solar radio burst. These receivers were all in the sun-lit hemisphere
and all were affected similarly. The maximum solar radio burst power
associated with the 7 September 2005 flare had a peak intensity of
about 8,700 solar flux units (1 SFU = 10-22 W/m2-Hz) RHCP at 1,600
MHz, which caused a corresponding decrease in the signal-to-noise
ratio of about 2.3 dB across all visible satellites. Only the
right-hand, circularly polarized (RHCP) emissions affected the GPS
signals.

To confirm the effect, the solar radio burst associated with the 28
October 2003 flare was investigated. Although polarization data were
not available for this event, the maximum degradation at GPS L1 was
about 3.0 dB, and a degradation of 10 dB was observed on the
semi-codeless L2 signal for a solar radio burst of 13,600 SFU.

The event analyzed herein can be used to scale historical solar radio
bursts of 80,000 SFU. Decreases of 12 dB (21 dB) in the L1 (L2,
semi-codeless) signal-to-noise ratio are implied along with loss of
tracking for inadequately designed GPS receivers. Since solar radio
bursts affect all satellites in view of a receiver, all receivers in
the sun-lit hemisphere, the new Galileo navigation system, and all
space-based augmentation systems such as WAAS and EGNOS, they are a
potential threat to life-critical systems.



Institute of Navigation in Fort Worth, Texas: http://www.ion.org/

Larry Dighera wrote:
On Wed, 25 Oct 2006 06:17:38 -0500, "Jim Macklin"
wrote in
:


BFD, All those radios are called Aids to navigation for a
reason, they are conveniences.


Were you aware of the design flaw in GPS as implemented? I just
thought it might be a good idea to provide the information to those
weren't.

Of course, this issue makes no mention of solar mass ejections, that
can potentially knock out any satellite.

It appears that we are (finally?) seeing some technological innovation
tickling down to the GA fleet, but I'm becoming uneasy with the
apparent lack of robustness engineered in these early systems.


CAL found Paris with just a compass and a chart.

Yes. It was an Earth Inductor Compass*. I've never seen one of those
in any aircraft in which I've flown, let alone piloted.


* http://oldbeacon.com/beacon/earth_inductor_compass.htm


Did anybody see NOVA on PBS last night. The earth is overdue for a pole
reversal. According to the program, we are already seeing issues towards
that. Interesting program.

--

Regards, Ross
C-172F 180HP
KSWI

On Wed, 25 Oct 2006 07:24:58 -0700, "Aluckyguess" wrote in
:

Im not worried.

Perhaps you should throw your hat in the ring:
http://politicalhumor.about.com/libr...bushworry2.htm

This is a rather alarmist exaggeration of reality.

--
Transpose mxsmanic and gmail to reach me by e-mail.

Larry Dighera writes:

Were you aware of the design flaw in GPS as implemented?

What design flaw?

It appears that we are (finally?) seeing some technological innovation
tickling down to the GA fleet, but I'm becoming uneasy with the
apparent lack of robustness engineered in these early systems.

They seem to be designed just like personal computers, which is very
bad and very dangerous for safety-of-life systems.

--
Transpose mxsmanic and gmail to reach me by e-mail.