The AN/MPQ-64 Sentinel is an X-band electronically steered pulse-Doppler 3D radar system used to alert and cue Short Range Air Defense (SHORAD) weapons to the locations of hostile targets approaching their front line forces.

[1] The system automatically acquires, tracks, classifies, identifies and reports high- and low-altitude targets, including cruise missiles, unmanned aerial vehicles, and both rotary- and fixed-wing aircraft.

[2] The upgrade provides a significant range extension and better detection against subsonic cruise missiles, slow-moving Unmanned Aerial Vehicles and drones, and rotary-wing and fixed-wing aircraft.

[3] The upgrade includes the TPX-57 Mode 5 Identification Friend or Foe (IFF) modification kit, which consists of a new Ethernet router, enhanced Radar Control Terminal (eRCT), Signal Data Processor (SDP) box, and multiple circuit card assemblies.

[5] The Sentinel A4 is a complete redesign of the sensor that uses digital processing and solid-state antenna modules based on gallium nitride (GAN) transmitters.

[2] Sentinel A4 will be able to contribute sensor data to the Integrated Air and Missile Defense Battle Command System (IBCS) network and Indirect Fire Protection Capability Increment 2.

Before its acquisition by the Raytheon Company, the Hughes Aircraft Co. developed the AN/MPQ-64 Sentinel radar at its plant in Fullerton, California, and manufactured it at its facility in Forest, Mississippi.