Can GPS jammers bring down a plane?

I always wondered if we’re putting to much faith in modern technology, but this article trumps all. A New Jersey man wanted to hide his movements from his employer by using a GPS jammer, but he ended up interfering with operations at a busy airport instead. He was tracked down, fired, and faces a fine of almost $32,000.


According to the article this was the device he was using.

OK, the guy was doing something wrong, but there are a few things bothering me.

  1. The range of these devices generally won’t exceed 10 meters. How on earth could this interfere with airport operations?
  2. How did authorities track down such a marginal (and probably fast moving) signal?
  3. If these devices are so dangerous, does that mean that terrorists can bring down planes in the future by buying a truck load of these things?

I’m puzzled. Something doesn’t make sense here. If it does, it might be wise not to put too much trust in these technologies.


On the drawing table: JPS

We all know GPS (Global Positioning System), but JPS? JPS stands for Jammer Positioning System which, hopefully, will evolve into an automated system to pinpoint the location of jammers without having to jump into a car. The theory is simple, execution is another matter. Tips, ideas and help welcome, feel free to borrow the idea and construct (parts of) a JPS yourself.

jpsHow JPS works
The system will rely on a number of stationary Doppler direction finders, which are mounted on the roof of a selected number of monitoring stations. The more stations the better, but geographic locations should be chosen carefully. The exact location of these Dopplers is determined by using a GPS. The exact coordinates will be used later in the process.

The LEDs, which are normally used to interpret the output of a Doppler direction finder, will be replaced by digital compass information which will be fed into a computer. The computer relays the data to a central server, which plots the data onto Google maps in real time. When built properly, an accuracy of ± 150 meters should be achievable, maybe better.

Manual tests with stationary Doppler direction finders proved that the concept itself is fine. We now think it’s time to round up a bunch of experts in various fields en get things on the road. Now it’s just an idea of mine which needs to materialize.