A GPS jammer, or jamming device or radio navigation satellite service (RNSS) jammer is most commonly a small, self-contained, transmitter device used block radio signals used for GPS locating.
Most commonly they are used to hide the users location by sending radio signals which conflict the same frequencies used by a GPS device.
When this signal jamming occurs, the GPS device is unable to determine its position due to the interference.
How does a GPS jammer works
To understand how a jammer works, it is important to know how GPS works.
Firstly, A GPS device receives signals from satellite transmitters which are in orbit above Earth, circling the globe at various velocities and altitudes.
Secondly, once the device receives a signal from multiple satellites it is able to determine its position through trilateration.
Thirdly, the GPS tracking device then transmits this position and velocity information to a monitoring location.
This position and velocity information is most commonly sent over the mobile network system.
And lastly, a user or system accesses this location information from the monitoring location.
A GPS jammer will break down this communication between device and satellite by emitting radio signals or signal noise with the same frequency as the GPS device.
This causes the frequencies clash with and override, distorting the GPS satellite signals.
As a result, when this occurs the GPS device can then no longer calculate its position because the satellite signal is masked by the interference.
Who uses GPS jammers?
The reasons for using jammers are varied. Originally created by the government, GPS jammers were designed for military use. Concealing vehicle location can be crucial to the success of a mission. The devices act as a cloak giving the military privacy, increased safety and an overall advantage in high-risk situations.
Among civilians, some speeding drivers may use jamming devices to try to prevent detection by police and avoid fines. Criminals use GPS jammers as cover for vehicle theft or to avoid toll charges or mileage charges. In the fleet world, GPS jamming could be used by a driver to prevent the employer from knowing where they are going with the company vehicle.
We have also seen unique business causes for the use of jammers.
For example, taxi cab drivers in Melbourne, Australia have been fined with blocking GPS signals at Melbourne airport.
They have done this to obtain rides even though they were not in the area.
The devices are said to be used by drivers to mask the location of the cab, allowing them to get a job even if they are not in the area.
Herald Sun
As the method of GPS jamming is illegal in Australia, they were fined $850 at the time.
Fines as of 2020 can reach up to $1.05 million in Australia or up to 5 years in prison.
Penalties for breaching the rules can be a fine of up to $1.05 million or up to 5 years in prison.
Are GPS jammers legal to use?
GPS jamming is illegal in many countries, such as Australia, the United states, Canada, and also in the UK.
Harsh penalties exist for using jammers, for example
In the United States, the federal Communications Act of 1934 outlawed the marketing, sale or use of GPS jammers.
Australia states that you are not allowed to use, supply or own a GPS jammer as per the Radiocommunications (Prohibition of PMTS Jamming Devices) Declaration of 2011.
Canada also prohibits manufacturing, importing, distribution, possession or the sale of GPS jamming devices.
How do GPS jammers impact the transportation industry?
GPS Jammers are both a nuisance and an issue for law enforcement, telematics and the transport industry.
Jamming interferes also with GPS vehicle tracking, which is commonly known as fleet tracking.
Fleet tracking is a critical source of business data to many companies.
Fleets use telematics to track and manage fuel use, driving behavior, idling, servicing of a vehicle, engine health and other activities.
Not only are jammers illegal, but using them can be dangerous.
A New Jersey truck driver was fined almost $32,000 by the Federal Communications Commission (FCC) when his GPS jamming device interrupted air traffic control information at Newark Liberty International Airport.
The truck driver had used the jammer in his work truck to hide his location from his employer.
An investigator for the FCC located the jammer using radio monitoring equipment and proved it was the cause of the interference.