GPS Anti-Jam Systems

Integrated power solutions from GPS is a key battlefield enabler, allowing precise location of military assets in a real-time environment; however, it is relatively easy to disrupt the GPS signal due to its extremely low power level. In battlefield and airborne operations, enemy countermeasures include the use of GPS denial effects, to disrupt and jam GPS.

Raytheon’s suite of anti-jamming products protects this weak point in modern infrastructure systems, including battlefield systems, ensuring the continuing operation of GPS critical timing systems in high radio frequency (RF) jamming operating theatres.
With over 20 years’ experience, Raytheon UK is a world leader in the development, production and supply of analogue and digital GPS anti-jamming systems to the majority of the world’s military forces. Currently, Raytheon UK provides GPS anti-jam systems to the UK Ministry of Defence, U.S. Department of Defense and more than 20 other nations. Raytheon UK has designed and manufactured in excess of 10,000 GPS anti-jam units for the worldwide market.
Learn more about our products:


Raytheon UK's next-generation digital GPS anti-jam protection system, Landshield®, is a step-changer in capability. It houses a multi-element antenna and the anti-jam processing in a single small, affordable, ‘one-box' solution that interfaces at RF level to the GPS receiver, with minimal system modification required. This cost-effective, small form factor and lightweight upgrade will simply replace existing unprotected GPS antennas, as well as enhance original installations where protection against jamming and interference is required.
Landshield® is available in two variants, Landshield® Simultaneous has a 4-element CRPA and Landshield® Plus has a 7-element CRPA.
Both Landshield® variants work against a full range of hostile jammers – including narrowband, broadband, continuous wave pulse, swept and spectrally matched – and can protect L1 and L2 GPS frequencies simultaneously for enhanced situational awareness.
Landshield® interfaces with standalone GPS receivers or those integrated within communication, inertial navigation, sighting, vehicle or weapon-aiming systems. These fully integrated GPS-AJ antennas are suitable for military, critical national infrastructure, maritime, government and avionics where low Size, Weight and Power constraints are key.  

Advanced Digital Antenna Production (ADAP)
The world’s first full digital, truly simultaneous GPS L1/L2 anti-jam system, Raytheon UK’s ADAP (Advanced Digital Antenna Production) solution has set the standard for GPS anti-jam technology currently in production. The system delivers proven GPS anti-jam performance in harsh airborne and maritime environments as well as complex high-threat solutions.
Performance Benefits:

  • Multi-element antennas mitigate multiple jammers during platform and jammer dynamics
  • Complies with future M-Code satellite signals, including threshold adjustment for spot beam and hot satellites
  • Provides jamming protection against higher power jammers through digital space time adaptive processing (STAP) algorithms
  • Comprehensive built-in test with automatic fault detection speeds maintenance
  • ADAP contains a multi-element antenna, digital anti-jam processing, and provides protected GPS L1 & GPS L2 for the majority of RF & IF input GPS receivers. It provides the user with an indication of the presence of jamming and its power; this information can be fed back into the tactical and strategic real-time awareness picture.


GPS Anti-Jam System-1 (GAS-1)
Installed on more than 30 platforms worldwide, Raytheon UK’s GAS-1 is the GPS Anti-Jam antenna global standard in a comprehensive product portfolio that covers air, land and sea applications in both analogue and digital designs.
GAS-1 technology consists of a multi-element Controlled Reception Pattern Antenna (CRPA) and separate Antenna Electronics (AE) unit which is able to recognise multiple sources of deliberate jamming and other electrical interference – such as mobile phone networks, satellite communications and High Definition terrestrial TV – and reject them. This allows the navigation equipment to function safely, accurately and efficiently in the presence of multiple jammers. In military use, jammer-protected targets can be approached more closely and all operations requiring GPS-derived position and time (UTC) can be carried out with greater accuracy and improved mission assurance.
It is the ability of GAS-1 to track jammers and generate nulls faster than any of its competitors that has seen it selected by the air forces of the United Kingdom, United States and Australia governments.


Anti-jam GPS Receiver (AGR)
Raytheon's Anti-jam GPS Receiver (AGR) supports the Tactical Tomahawk missile programme. The AGR is a PPS (i.e., Y-code) GPS receiver that operates on both the L1 and L2 frequencies. When configured with a multi-element Controlled Reception Pattern Antenna (CRPA), the AGR's post-correlation nulling techniques allow continued satellite track in the presence of high levels of hostile jamming.
The AGR's patented approach to anti-jam also implements satellite beam steering, to further enhance the tracking thresholds, and to mitigate the "spurious nulls" that can degrade the performance of other nulling implementations (e.g., pre-correlation).
The AGR sequentially tracks up to eight visible satellites, and provides high-quality pseudorange/delta pseudorange (PR/DPR) measurements corrected for the effects of selective availability. The tactical Tomahawk missile's navigation processor then uses the PR/DR measurements to yield a high-performance navigation solution.
Advanced GPS Inertial Navigation Technology (AGINT)
Raytheon was selected by AFRL to develop an affordable, small, anti-jam GPS receiver system using frequency spatial time adaptive processing (FSTAP). The AGINT design has a multi-element RF front end, digital adaptive A/J filter, and SAASM GPS receiver.
In Phase I, Raytheon demonstrated a breadboard to show the feasibility of the proposed AGINT processing concept and technology.
The Phase II effort developed a brassboard, which is capable of 120 dB of jamming protection against multiple broadband and narrowband jammers, and can provide beamsteering to four separate GPS satellites.