GPS chaos: How a $30 box can jam your life

veritas_libertas

IT WAS just after midday in San Diego, California, when the disruption started. In the tower at the airport, air-traffic controllers peered at their monitors only to find that their system for tracking incoming planes was malfunctioning. At the Naval Medical Center, emergency pagers used for summoning doctors stopped working. Chaos threatened in the busy harbour, too, after the traffic-management system used for guiding boats failed. On the streets, people reaching for their cellphones found they had no signal and bank customers trying to withdraw cash from local ATMs were refused. Problems persisted for another 2 hours.

It took three days to find an explanation for this mysterious event in January 2007. Two navy ships in the San Diego harbour had been conducting a training exercise. To test procedures when communications were lost, technicians jammed radio signals. Unwittingly, they also blocked radio signals from GPS satellites across a swathe of the city.

GPS chaos: How a $30 box can jam your life - tech - 06 March 2011 - New Scientist

Devilsbane

Which is why they are illegal to have and use.

I was reading an article recently that expected GPS to completely fail in the next couple years if no action was taken. It has been many years since any satellites have been deployed. So we have old satellites paired with the massive increase in usage. It is just a matter of time.

tiersten

Not a new idea at all. Its been a known issue with GPS and pretty much every other radio based communication system since they were invented. A jammer is easy and cheap to build because you don't need to be very accurate. If your only intention is to jam a signal then you can just blast an entire frequency range with little care about overlap or the actual signal itself.

The article does have a certain amount of media frenzy and scare mongering. The claim that everything just died when the Navy was jamming is a bit suspicious and I think its more likely that the article is just carefully avoiding the fact that they were also jamming other frequencies, not just GPS.

Just because the GPS signal is lost/jammed doesn't mean that everything that uses a GPS to synchronise their clocks will suddenly fall over and die. All of the GPS timebase units I've used and seen have all had their own temperature compensated and calibrated internal clock inside as well which is what actually keeps track of the time. The internal clock is very accurate over short periods of time so a minor outage of only 2 days is nothing.

tiersten

Devilsbane wrote: »

I was reading an article recently that expected GPS to completely fail in the next couple years if no action was taken. It has been many years since any satellites have been deployed.

Last year is many years? :P The rest of the IIF block satellites are being prepared for launch sometime this year.

Unless there is a catastrophic failure of the majority of the GPS satellites or groundstations then the worst that happens is that accuracy degrades.

steve13ad

Alright who else Googled GPS Jammers?

I was surprised at the how low some where priced!