Posts Tagged ‘gps jammer’

GPS interference and jamming

Sunday, May 25th, 2008

Natural sources

Since GPS signals at terrestrial receivers tend to be relatively weak, it is easy for other sources of electromagnetic radiation to desensitize the receiver, making acquiring and tracking the satellite signals difficult or impossible.

Solar flares are one such naturally occurring emission with the potential to degrade GPS reception, and their impact can affect reception over the half of the Earth facing the sun. GPS signals can also be interfered with by naturally occurring geomagnetic storms, predominantly found near the poles of the Earth’s magnetic field. GPS signals are also subjected to interference from Van Allen Belt radiation when the satellites pass through the South Atlantic Anomaly.

Artificial sources

Metallic features in windshield, such as defrosters, or car window tinting films can act as a Faraday cage, degrading reception just inside the car.

Man-made EMI can also disrupt, or jam, GPS signals. In one well documented case, an entire harbor was unable to receive GPS signals due to unintentional jamming caused by a malfunctioning TV antenna preamplifier. Intentional jamming is also possible. Generally, stronger signals can interfere with GPS receivers when they are within radio range, or line of sight. In 2002, a detailed description of how to build a short range GPS L1 C/A jammer was published in the online magazine Phrack.

The U.S. government believes that such jammers were used occasionally during the 2001 war in Afghanistan and the U.S. military claimed to destroy a GPS jammer with a GPS-guided bomb during the Iraq War. Such a jammer is relatively easy to detect and locate, making it an attractive target for anti-radiation missiles. The UK Ministry of Defence tested a jamming system in the UK’s West Country on 7 and 8 June 2007.

Some countries allow the use of GPS repeaters to allow for the reception of GPS signals indoors and in obscured locations, however, under EU and UK laws, the use of these is prohibited as the signals can cause interference to other GPS receivers that may receive data from both GPS satellites and the repeater.

Due to the potential for both natural and man-made noise, numerous techniques continue to be developed to deal with the interference. The first is to not rely on GPS as a sole source. According to John Ruley, “IFR pilots should have a fallback plan in case of a GPS malfunction”. Receiver Autonomous Integrity Monitoring (RAIM) is a feature now included in some receivers, which is designed to provide a warning to the user if jamming or another problem is detected. The U.S. military has also deployed their Selective Availability / Anti-Spoofing Module (SAASM) in the Defense Advanced GPS Receiver (DAGR). In demonstration videos, the DAGR is able to detect jamming and maintain its lock on the encrypted GPS signals during interference which causes civilian receivers to lose lock.

Get Rid of Your Stalkers With Portable GPS Tracking Jammer

Sunday, May 11th, 2008

Portable_GPS_Tracking_JammerFeeling unsecure and got no more private life. Use this little device to screw up GPS signal before it can be reached by any GPS devices, and transmit back to your stalkers.

A company base in Taiwan, Web Strategies Ltd. (WSL) feel responsible to produce this gadget in order to provide private life to whom life have always been stalked by some kind of paparazzis or maybe mafia in their everydays life. Protecting your whereabouts and movements from citizen and vehicle tracking personnel with 1933key’s Portable GPS Tracking Jammer utilizes unique and intelligent technology to interfere with GPS satellite signals and GPS receivers. You now can decide to be either on or off someone’s satellite tracking radar.

Using a standard mobile phone battery pack and battery charger, the Portable GPS Tracking Jammer is ready for mobile operations anytime. The included direct power pack allows continuous operation even when the batteries are drained.

No complicated installation or professional spy knowledge is required for operation. Sleek handheld design provides easy to carry and easy to use functions, anytime, anywhere.


  • Blocks GPS tracking, tagging, stalking and surveillance devices to protect your movement privacy.
  • Prevents mobile GPS logging systems from submitting geographical positioning data to base tracking stations.
  • Cautions-Not for use near GPS dependent motorized craft such as airplanes, farm equipment, ships or yachts; nor should used for vehicle theft.


  • Jamming distance (coverage radius)
    Model: JGPS01A: Up to 40 meter diameter-20 meter radius
    Model: JGPS01B: Up to 20 meter diameter-10 meter radius
  • Antenna: Internal
  • Dimensions: L 139 x W 49 x H 24 mm
  • Power: 4. 8v DC rechargeable battery pack or car power supply (cigarette lighter plug)