Can a GPS jammer prevent cell phone queries?

A few years ago, when satellites were touted as the only aviation navigation tool from takeoff to landing, ex-FAA administrator Langhorne Bond painted a picture of a dark winter night with severe weather on the east coast. In this scenario, terrorist gps jammer could become “weapons of mass destruction”. The FAA shook it off as unsubstantiated speculation. However, in a recent report on the GPS-dependent ADS-B, the Inspector General of DOT took the matter much more seriously and called on the FAA to “work with US intelligence agencies to assess such potential threats.”

Surprisingly, it now turns out that the most likely carriers of these weapons of mass destruction today are the good old boys and girls who run the country’s 18-wheeler fleet. Where from? This is due to the ubiquity of GPS and its ever-growing applications. Almost all large trucks have small GPS receivers on their cabins and associated cell phones that company dispatchers can use to monitor progress without speaking to the driver.

And yes, you guessed it. If a driver wants to make an unauthorized stop for a coffee or something similar, he or she sticks a small GPS jammer in the cigarette lighter and overwhelms the weak satellite signals with an interference hash. In order to counteract this, the developers of the tracking system determined that they could roughly triangulate the position of the cell phone from three cell phone masts. In response, newer GPS jammers can now block incoming cell phone queries, preventing triangulation attempts. The cat and mouse game continues.

And these jammers are cheap. A Chinese GPS / cell phone device was offered for $ 22.65 at a New Year’s sale on the Internet. However, the range of the interference signals was only a little over five meters, which would likely scare off most potential buyers, although it would be sufficient to disable the GPS and associated cell phone receivers on a truck cab roof just above the driver’s head. However, most customers probably want more performance and opt for more muscle units with a range of more than three miles. A macho thing maybe, but this is where the trouble starts, like at Newark Liberty International Airport.

During the last test phase of Newark’s Laas GPS precision approach device on Runway 29, the system was shut down frequently and inexplicably. The cause was the interference from GPS jammers on trucks that drove past the nearby New Jersey Turnpike.

This has put the owners of the Laas equipment – the Port Authority of New York and New Jersey (PANYNJ) – as well as Continental Airlines and the FAA in a kind of dilemma. In a December 2008 PANYNJ press release, the agency estimated that it would spend $ 2.5 million on the purchase, installation, and maintenance of the floor system. Continental would spend approximately $ 1.1 million on equipping 15 aircraft and training pilots, and the FAA would spend $ 2.5 million on technology assessment. The FAA recently reported that Continental had equipped 18 Boeing 737NGs by August 2010.

The Newark Laas installation cannot be certified for IFR approaches. AIN is aware that Honeywell – the manufacturer of the system – intends to have an interference mitigation project (but not necessarily a final solution) for FAA testing and certification ready to integrate with Continental’s Laas site , which is planned for Continental in Houston and for retrofitting the Newark system.

The legal problems associated with GPS interference are not entirely clear. It is certainly illegal to intentionally interfere with government or federal agencies, or with public transportation. The deliberate use of lasers against aircraft is an obvious example. But when you point someone at a plane with a laser after plane reports, it’s one thing to prove to a court that interference from a nearby ATC system by a particular passing vehicle would be deliberate rather than unintentionally different. There are reports that there are currently several thousand GPS / cell phone jammers, many in vehicles other than trucks.

Indeed, one group that will undoubtedly follow Honeywell’s investigation is law enforcement. The miniature GPS and mobile phone receivers on the roofs of a truck cab – if they are packed with a small but powerful magnet – can be accidentally inserted into it by an agent