On Wed, 25 Oct 2006 14:05:05 GMT, Larry Dighera
wrote in :

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 your 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.

SPACE WEATHER THREATENS GPS

As if we didn't have enough weather to worry about here on Earth,
scientists have confirmed what has long been anecdotally acknowledged
-- that solar flares play havoc with GPS signals. And with the FAA
moving steadily toward satellite-based technologies for the future of
airspace management, the warnings from last week's Space Weather
Enterprise Forum
(http://www.prnewswire.com/cgi-bin/st...04559768&EDATE)
take on increasing poignancy. "Society cannot become overly reliant on
technology without an awareness and understanding of the effects of
future space weather disruptions,'' Anthea Coster, Ph.D., MIT Haystack
Observatory, told attendees at the conference, which was held in
Washington, D.C. There is some good news, however. It appears WAAS
signals, the cornerstone of most of the new navigation protocols, are
somewhat less vulnerable to disruption.
http://www.avweb.com/eletter/archive...ll.html#194884