A GPS jammer is any device that blocks, jams or interferes with GPS transmissions or operations. Interfering with GPS is not difficult as GPS signals are received with very low signal power. Hence, GPS jamming devices are fairly simple to manufacture. In the United States, GPS jammers are illegal and their use can result in large fines. Despite the prohibition, many cases of interference are experienced every year.
Stanford has been performing research on how to make GPS and GPS receivers more robust to mitigate interference from jammers. Current research includes the following techniques:
- Single element antennas
- Adaptive antennas
- Beam steering antennas
The FAA currently supports Stanford’s on-going research.
View article: J911: Fast Jammer Detection and Location Using Cell-Phone Crowd-Sourcings by Logan Scott, GPS World, November 1, 2010