Is R-EGI built on pntOS?

Yes. R-EGI's open architecture is built on pntOS for fusion, along with FACE for software, SOSA-aligned OpenVPX hardware, an internal DDS data model, and the ASPN standard for sensor interfaces.

What keeps R-EGI navigating when GPS is lost?

A chip-scale atomic clock and inertial sensors hold time and position through short outages, and a fusion engine brings in alternative-navigation sources such as celestial, vision, magnetic, and terrestrial for longer denials.

Why does R-EGI separate safety-critical from mission navigation?

So a rapid resilience upgrade to mission navigation does not trigger recertification of the flight-critical safety navigation. R-EGI splits into a safety-critical and a mission-capability processing environment.

Which aircraft use R-EGI?

The F-16 is the threshold program and the F-15E/EX effort began in 2023. The architecture is designed for other platforms to adopt.

The Air Force, through AFLCMC. A core goal of the program is that the government owns the rights to the key interfaces.

R-EGI: The Air Force's Resilient Embedded GPS/INS

Part of the Open Architecture Field Guide. All information is derived from unclassified, publicly releasable (Distribution A) sources.

R-EGI, Resilient-Embedded GPS/INS, is the Air Force's open-architecture program for navigation that survives GPS jamming and spoofing. It fuses GPS and inertial with a chip-scale atomic clock and multiple alternative-navigation sources, and it is built on open standards including pntOS, ASPN, FACE, and SOSA. It is the Chief of Staff of the Air Force's designated preferred resilient-PNT solution.

What it does

Aircraft navigation leans on GPS, and GPS is jammed and spoofed across the theaters that matter. An embedded GPS/inertial unit bridges short outages on inertial alone, but inertial drifts, so a long denial still degrades the position. The gap has been a way to bring in other navigation sources quickly, from different vendors, without a bespoke integration each time.

R-EGI is built for that. It fuses GPS and inertial with a chip-scale atomic clock, and it adds a fusion engine that takes multiple alternative-navigation inputs such as celestial, vision, magnetic, and terrestrial. When GPS is degraded or denied, the system continues on inertial and the alternatives, tailoring the navigation to the mission. It is designed for plug-and-play integration of third-party sensors.

Spectral Autonomy

R-EGI fuses GPS with inertial, a chip-scale atomic clock, and alternative-PNT sources, and continues on the alternatives when GPS is denied.

How it is built

R-EGI is described as more than a box: it is an environment, a line-replaceable unit, and an architecture. The unit splits into a Common Core that is shared across platforms and a Platform Interface that is unique to each aircraft. It also separates safety-critical navigation from mission-capability navigation, so a rapid resilience upgrade does not force recertification of the flight-critical functions.

It is built on open standards. Software is built to FACE; the hardware is VITA OpenVPX with profiles defined for future SOSA adoption; pntOS provides the fusion; an internal DDS data model and the ASPN standard cover the sensor interfaces; and the platform is reached through OMS or legacy interfaces. A design goal throughout is that the government owns the rights to the key interfaces.

Where it sits

R-EGI is part of the PNT family, on the Air Force side. It is built on pntOS and the ASPN data standard, the same open PNT software and data standards the Army uses and that the PNT Standards Consortium now governs. R-EGI is owned by an Air Force program office. The Chief of Staff of the Air Force designated it the preferred resilient-PNT solution, and it is being fielded on the F-16 as the threshold program and on the F-15E/EX.

Spectral Autonomy

R-EGI and the Army's PNT systems both build on pntOS and ASPN, the open PNT software and data standards.

Where this fits

pntOS: The Open Plugin Architecture for PNT Sensor Fusion — the open fusion framework R-EGI is built on
ASPN: The All-Source Positioning and Navigation Data Standard — the data standard R-EGI uses for sensor interfaces
FACE: The Standard for Portable Avionics Software — the software standard R-EGI's architecture is built to
SOSA: The Sensor Open Systems Architecture — the hardware standard R-EGI's OpenVPX modules move toward
The PNT Standards Consortium — the body that now governs pntOS and ASPN

FAQ

Is R-EGI built on pntOS?: Yes. R-EGI's open architecture is built on pntOS for fusion, along with FACE for software, SOSA-aligned OpenVPX hardware, an internal DDS data model, and the ASPN standard for sensor interfaces.
What keeps R-EGI navigating when GPS is lost?: A chip-scale atomic clock and inertial sensors hold time and position through short outages, and a fusion engine brings in alternative-navigation sources such as celestial, vision, magnetic, and terrestrial for longer denials.
Why does R-EGI separate safety-critical from mission navigation?: So a rapid resilience upgrade to mission navigation does not trigger recertification of the flight-critical safety navigation. R-EGI splits into a safety-critical and a mission-capability processing environment.
Which aircraft use R-EGI?: The F-16 is the threshold program and the F-15E/EX effort began in 2023. The architecture is designed for other platforms to adopt.
Who owns R-EGI?: The Air Force, through AFLCMC. A core goal of the program is that the government owns the rights to the key interfaces.

Sources

The R-EGI MOSA Overview — AFLCMC/ESC MAR JPO, Jan 2026 (approved for public release, AFLCMC-2024-0112)
R-EGI proves resilient navigation in GPS-denied flight tests — Inside GNSS
Air Force launches Phase 2 of R-EGI — Inside GNSS