What is GPS Jamming?

GPS Jamming is the process of using an RF transmitting device to intentionally block or interfere with GPS signals that are used for positioning, navigation and timing. These RF transmitting devices are called GPS jammers and are relatively small and simple transmitting devices that emit RF signals of the same frequency as GPS signals. These foreignly emitted signals can interfere with GPS signals and cause disruptions in reception leading to inability or inaccuracy in GPS receivers when calculating position and time.

The Global Positioning System (GPS) uses a series of earth-orbiting satellites that send out radio signals. The signals have to travel a long way to reach GPS receivers and hence become very weak by the time they reach the earth’s surface. A GPS receiver needs GPS signals from 3 different GPS satellites to calculate its position accurately. GPS signals are radio signals that use a specific frequency. GPS uses two major frequency bands - 1575.42 MHz for public and non-military use and 1227.6 MHz for the US military. Since GPS receivers receive weak radio waves from the satellites, they can be easily be jammed or distorted by using stronger RF signals which mimic the signals received from the satellite by using a GPS jammer.

GPS jammers were initially created by the government, for military organizations and spy agencies. They used them for confusing the enemy on the exact locations of military vehicles or where the GPS-guided missiles or bombs will fall. Jammers acted as a cloak giving the military privacy, increased safety, and an overall advantage in high-risk situations.

Eventually, civilian GPS jammers also became available as RF transmitter technology became smaller and cheaper to produce. They were produced for consumers that wished to ensure their privacy or prevent tracking of their locations and usually worked even up to 10 meters. However, without proper technical knowledge or when placed into the wrong hands, these GPS jammers can cause potentially damaging disruptions in communications. Criminals could use these easily available civilian GPS jammers to conceal their locations or even the locations of items they have stolen like vehicles, mobiles etc. These civilian jammers could even potentially disrupt other forms of RF signals even when used with good intentions like cellular, radars etc. They could disrupt business-critical GPS applications operations and data like fleet management, asset tracking etc. or even disrupt communications involving airport radio towers or airplanes which may lead to major disasters. Due to these evidently high-risk scenarios involving GPS jammers, they have been banned from being produced, sold or bought in many major countries like USA, UK etc.

What is GPS Anti-Jamming?

GPS anti-jamming is the process of protecting GPS receivers from interference and intentional jamming. This is done using GPS Anti-jamming devices that can detect the interference signals and even the direction they are coming from and deploy counter-measures to nullify those signals. GPS anti-jamming is particularly used by military forces to protect their devices from enemy jammers. Lately, some civilian GPS modules also have a certain degree of anti-jamming capabilities built-in to protect them against jammers. Click here to see GNSS anti-jamming solutions from the leading manufacturers.

Another tactic to disrupt GPS signals is spoofing. Click here to learn more about spoofing.