Criminal gangs are apparently using increasingly sophisticated devices called jammers to disrupt satellite navigation signals that guide sat-navs and other navigational devices with potentially devastating consequences.
GPS devices use very weak signals from four satellites circling the earth with each of them outputting less power than a 25W bulb more than 20,000 Km from the Earth surface. It is therefore quite easy to literally flood nearby GPS even with very low power jammers.
David Last, a consultant engineer and former president of the Royal Institute of Navigation, told an audience at the National Physical Laboratory in Teddington yesterday that the current trend is for car thieves to use jammers to disable the tracking security systems embarked on expensive cars and lorries.
However, there's a possibility that terrorists could use the more powerful versions to cause havoc around airports by flooding the timing signal that is crucial to some onboard positioning systems.
For the time being though, criminals are resorting to importing the gadgets from China; a quick search for Jammer GPS China brought up one from Chinavision for as little as £19.64 and which can jam phones and GPS up to a range of 10 meters.
What's even more worrying though is that receivers can be tricked for example into believing that they are moving when they are actually stationery.
Professor Last gave the example of how a low cost simulator can be linked to Google Earth and the data gathered after running a virtual route used to fool the target GPS receiver.
GPS Jammers are a real risk and one which must not be taken lightly. It is surprising that so much chaos can be created by such a small device. The UK government, we understand, is working on a number of solutions to counteract this growing menace.