Who’s Protecting the GPS?

In economics, experts speak of the “law of unintended consequences.” This critical law states that whenever we initiate a program or policy to accomplish a specific goal, it will also trigger other effects—consequences—that we did not necessarily mean to trigger. Thus, prohibition on alcohol led to increased mob activity; World War II drew women into the public workforce as never before; and the international student visa program allowed dangerous terrorists to make their way to the United States with ease. The rise of GPS has had an unintended consequence related to terrorism as well, although thankfully it has not led to a large-scale attack. Recognizing the danger, numerous companies are working hard to minimize the terrorism risk of using GPS.

GPS Jamming

The primary threat to GPS is the possibility of jamming its signal. Particularly in military and commercial aircraft settings, dependence on GPS for navigation means that disruption of the signal could easily be catastrophic. Equipment that could be used to jam GPS frequency is notoriously inexpensive and easy to obtain, and with a little technical expertise, it is easy to imagine a terrorist using such equipment to throw a major airport or military base into confusion.

But it doesn’t take an intentional act of terrorism to create such confusion. Just as you can purchase a radar detector to avoid getting a speeding ticket, you can purchase a jammer (cheaply but illegally) to keep your employer from tracking your company vehicle. Although unscrupulous, this activity is common, and it sometimes disrupts other GPS applications. Here are a few recent examples:

• The London Stock Exchange regularly suffers from GPS outages, apparently caused by a vehicle-mounted GPS jammer nearby.


• A fleet driver’s jammer disrupted a new air traffic system at Newark airport, costing him over $31,000 in fines.


• Drivers in congested areas on British roads frequently lose GPS signal, probably because of nearby jammers in fleet vehicles.

What Could Happen?

A driver who loses GPS navigation capabilities might need to stop and ask for directions instead. But the situation is far more dire when an air traffic control tower suddenly loses access to the network. And during wartime, GPS jamming could easily become an enemy’s valuable weapon against attack by U.S. forces.

Yet another device is needed: a piece of equipment that can “jam the jammer.” Shielding a GPS device from signal interference is essential, and will almost certainly become standard within the next few years. One of the leading manufacturers in this new field is Raytheon, a Massachusetts-based company with a second base in the U.K.

Raytheon’s Developments

To date, Raytheon has implemented the following jammer protections with the cooperation of governments and other companies:

Product	Customer
GPS Anti-Jam	Northrop Grumman Italia, for military aircraft
GPS Anti-Jam	Airbus military aircraft
GPS Anti-Jam Land	U.K. Ministry of Defense
MiniGAS	Classified
Landshield	In Development

 

The final two products on the list, MiniGAS and Landshield, are currently in development and promise increased jammer protection in a more compact package. Most applications of these products are military in nature, reflecting the primary importance of national defense over commercial and personal devices. As with the GPS network itself, modifying jammer protection for civilian use will be an easy transition for manufacturers to make.

For obvious reasons, the details of GPS anti-jamming device development are often surrounded by secrecy. Broadcasting how, when, and where anti-jamming is being used would be counterproductive to defense efforts, giving potential terrorists and enemies a head start on coming up with ways to get around the devices.

The Future of GPS Safety

You may be wondering if we are at the start of a never-ending series of devices. Once we develop an effective shield to the jammer, will we see enemies build a device to disable the shield? Will we then invent a device to oppose that device?

Who’s Protecting the GPS?