What is GPS Anti-Jamming?

GPS Anti-Jamming protects GPS receivers from interference and intentional jamming. By the time the GPS signal reaches the Earth's surface is weak and is susceptible to being overcome by higher power Radio Frequency (RF) energy. Even a small jammer of about 10 Watts power can disrupt an unprotected C/A Code receiver for about 30 kilometres (line of sight). GPS Anti-Jamming uses power minimization to reduce the effect of interference and jamming so that the GPS receiver can continue to operate correctly. 

GPS technology has revolutionized modern warfare. Military organizations regularly depend on satellite technology for accurate positioning, timing and communications.

But GPS signals received on Earth are weak and susceptible to interference and intentional jamming. Indeed, the signals are usually obscured by thermal noise and only observable with a tuned signal analyser - in other words a GPS receiver.

A simple low power jammer, readily available via the World Wide Web, can overpower GPS signals within a large area, denying a position solution and timing.

GPS anti-jam technology is quickly evolving. Until recently, size and cost considerations meant anti-jam systems were only feasible for expensive assets, such as strategic aircraft and capital ships.

GAJT® - GPS Anti-Jam Technology

NovAtel's approach to the problem is to build a range of compact and affordable anti-jam systems for land, sea, air (including unmanned aerial systems), and fixed installations.

GAJT is a null-forming system that preserves the antenna's view of the GPS satellites while ignoring jammers, ensuring the satellite signals required to compute precise position remain available.

The GAJT range of products provides anti-jam performance at a significantly lower cost than others and is available off-the-shelf for rapid deployment.

GAJT works with any installed GPS receiver and is ready for M-Code.

The nominal performance of GAJT is 40 dB of interference suppression. Of course, the performance is scenario-dependent but this means effectively that you can operate safely 100 times close to a jammer than without protection. The whole system performance is the sum of GAJT interference suppression plus that provided by the installed receiver itself.