New Scientist takes a look at how the proliferation of GPS jammer devices is creating problems. The article by David Hambling calls GPS the “invisible utility” that is used as more than just an aid for navigation. GPS jammers have become more readily available for purchase on the Internet and are being used more widely than ever before by those wishing to block GPS signals on their vehicles. The jammers, if unobstructed, can interfere with GPS signals up to several kilometers away. The effectiveness of jammers is in part due to the inherent weakness of GPS signals:
“The problem is that the GPS signal is very weak. It’s like a car headlight 20,000 kilometres away,” says consultant David Last, former president of the UK’s Royal Institute of Navigation. You can’t boost the signal any further because of the limited power supply on a satellite.
GPS jammers can be bought over the Internet for as little at $30 and, among the users, are truckers that want to block GPS tracking of their vehicles. Jammers are also used to block GPS-based road tolls. In fact, the user of a jammer by a trucker to avoid tolls was responsible for shutting down the GPS-based landing system at nearby Newark International Airport in New Jersey.
It’s not only jammers that are causing problems. GPS spoofers are also starting to proliferate. Spoofers are used to manipulate GPS devices into providing a false reading. (via The Map Room)
- GPS chaos: How a $30 box can jam your life
- Jamming the Global Positioning System – A National Security Threat: Recent Events and Potential Cures (PDF) – Report from the National Executive Committee for Space-Based Positioning, Navigation, and Timing (PNT)