BAE Systems DIGAR-500M Digital GPS Anti-Jam Receiver

History

The BAE Systems DIGAR-500M is a digital military GPS anti-jam receiver developed to provide assured positioning, navigation, and timing in environments affected by GPS jamming and spoofing. The receiver combines M-Code compatibility with digital beamforming and is intended for airborne and maritime applications.

The DIGAR-500M was selected to support the U.S. Navy's transition of the Joint Precision Approach and Landing System, or JPALS, from Selective Availability Anti-Spoofing Module technology to M-Code GPS. Its dual compatibility allows legacy SAASM-equipped aircraft and M-Code-equipped aircraft to operate during the transition.

The specific DIGAR-500M effort for JPALS entered development in 2026 under a $16 million contract awarded to BAE Systems by Collins Aerospace. Work is performed at BAE Systems' military GPS engineering and manufacturing facility in Cedar Rapids, Iowa.

Development background

JPALS is a differential GPS-based precision approach and landing system used to guide tactical aircraft during recovery to aircraft carriers and amphibious assault ships. The U.S. Navy declared JPALS initial operational capability in May 2021 after installation, integration, and flight certification aboard USS Carl Vinson.

BAE Systems had previously developed the broader DIGAR family as a military GPS anti-jam system for fixed-wing aircraft, rotary-wing aircraft, unmanned aircraft, ships, and ground vehicles. By 2022, the DIGAR family had been expanded to support beamforming with Trimble GPS receivers in addition to BAE Systems receivers, including receivers integrated with Embedded GPS Inertial Navigation Systems and stand-alone GPS installations.

In 2026, Collins Aerospace contracted BAE Systems to design and develop the M-Code GPS solution for the Navy's JPALS modernization. The DIGAR-500M was designated as the receiver for this upgrade. The program is intended to strengthen JPALS resistance to interference while maintaining compatibility with aircraft that continue to use SAASM receivers.

Design

The DIGAR-500M combines military GPS reception with digital beamforming intended to maintain usable positioning, navigation, and timing data in the presence of deliberate or unintentional electromagnetic interference. The system provides anti-jam and anti-spoof protection and can form as many as 24 simultaneously steered beams.

The receiver supports both legacy SAASM operation and the U.S. military's encrypted M-Code GPS signal. This dual-mode capability is intended to permit gradual JPALS modernization without requiring all participating aircraft to transition to M-Code at the same time.

Digital beamforming

The DIGAR product line uses antenna electronics and signal processing to control GPS reception patterns electronically. Digital beamforming allows the system to steer reception while suppressing interference from unwanted directions. For JPALS, this capability is intended to improve the resilience of navigation data during precision carrier approaches and landings.

JPALS integration

JPALS combines shipboard GPS sensors, antennas, navigation equipment, aircraft equipment, and an encrypted anti-jam datalink to provide precision approach guidance. The DIGAR-500M forms part of the planned M-Code modernization of this architecture. Its ability to operate with both SAASM and M-Code is intended to support mixed-aircraft configurations during the transition.

Program status

As of 2026, the DIGAR-500M was being developed for integration into the U.S. Navy JPALS M-Code upgrade. The $16 million development contract covers BAE Systems' contribution to the M-Code GPS solution through Collins Aerospace. The available program information does not establish a production quantity or service-entry date for the DIGAR-500M.

Specifications (DIGAR-500M)

General characteristics

• Type: Digital military GPS anti-jam receiver
• Primary role: Assured positioning, navigation, and timing with protection against GPS jamming and spoofing
• GPS compatibility: SAASM and M-Code
• Signal processing: Digital beamforming
• Simultaneous steered beams: Up to 24
• Supported applications: Airborne and maritime platforms
• Planned JPALS role: M-Code GPS receiver supporting precision carrier landing operations and mixed SAASM/M-Code aircraft configurations