GPS Anti-Jam Systems

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 nearly 20 years’ experience, Raytheon UK is a world leader in the development, production and supply of 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 world-wide market. Read about its GAS-1, Landshield, Small Antenna System (SAS) Advanced Digital Antenna Production (ADAP) and Mini-GAS, products.

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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.

The system works 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. Weighing just 1kg, the typical installations it is suitable for are: military, critical national infrastructure, maritime, government and avionics where low Size, Weight and Power constraints are key.

Small Antenna System (SAS)

Small Antenna System (SAS) is a low-cost, high performance GPS Anti-Jam upgrade solution for replacing and enhancing original helicopter installations and other compact platforms. It provides the user with an indication of the presence of jamming, so this information can be fed back into the tactical and strategic real-time awareness picture.

Derived from Raytheon proven digital technology currently in production, SAS protects the enemy’s GPS jamming countermeasures in the modern battlefield system while ensuring the continuing function of GPS and maintaining situational awareness in jammed environments. The reduced size of SAS makes it an ideal product for rotary platforms and for the protection of GPS navigation on Unmanned Aerial Vehicles (UAVs), small ships and weapons.

SAS contains a multi-element antenna, digital anti-jam processing and interfaces simply at the RF level to stand-alone GPS receivers, or those integrated within secure communication, inertial navigation, sighting, or weapon-aiming systems.

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 HD 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, the United and Australia governments.


MiniGAS is a cost-efficient, high-performing, “one-box” GPS anti-jam protection system which contains a multi-element antenna and anti-jam processing in a single compact housing. Designed and manufactured by Raytheon UK, this GPS anti-jamming solution offers light, small and flexible form factors for land, unmanned aerial vehicles and missile platforms with minimal system modification required.

MiniGAS protects GPS jamming enemy countermeasures in modern infrastructure systems, including battlefield systems, thus ensuring the continuing operation of GPS critical timing systems when in jammed or Radio Frequency (RF) denial environments.

Integration and upgrade is made simple. MiniGAS is able to interface with multiple equipments, military and non-military, standalone GPS receivers or those integrated within communication, inertial navigation, SCADA and synchrophasor systems. Like Landshield™, its reduced size and weight, increased power and lower costs make it a competitive customer solution.


Anti-jam GPS Receiver (AGR)

Raytheon's Anti-jam GPS Receiver (AGR) supports the Tactical Tomahawk missile program. 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.