The new Controlled Reception Pattern Antenna (CRPA) is part of the Digital GPS Anti-jam Receiver (DIGAR) system to be installed on the F-15E Strike Eagle following a 2022 contract with BAE Systems.
Defense observers have noticed a new Controlled Reception Pattern Antenna (CRPA) appearing on a U.S. Air Force F-15E Strike Eagles photographed during Operation Epic Fury. The circular array is visible on the top of the fuselage, on the starboard (right) side, just next to the speed brake.
‘Abd’, a prominent military aviation analyst at The DIGAR upgrade emerged in September 2022 when BAE Systems received a $13 million contract to install the system on F-15Es at its facility in Cedar Rapids, Iowa.
RMP stands for Radar Modernization Program to replace the F-15E’s outdated APG-70 with the APG-82(V)1 Active Electronically Scanned Array (AESA) radar, while MUOS and SATURN stand for Mobile User Objective System for NATO and Second Generation Anti-Jam UHF Radio, respectively.
The official image capturing the F-15E with the new system was taken on April 5, 2026, and posted to DVIDS on April 7. This photo is part of a gallery showing an F-15E and F-35A Lightning II receiving fuel from a KC-135 Stratotanker in the U.S. Central Command (CENTCOM) Area of Responsibility (AOR).
It should have similar purpose/function to the IAI ADA GNSS anti-jamming module mounted on the Israeli F-15 and F-16, among other platforms. Both use CRPA beamforming to protect military GNSS/GPS (including SAASM/M code) from interference while feeding protected PNTs to existing receivers. pic.twitter.com/QuFbY6qMHm
— Abd (@blocksixtynine) April 9, 2026
CRPA uses multiple antennas to prevent jamming and ‘spoofing’ of satellite navigation (SATNAV) signals from US GPS and other constellations such as Russia’s GLONASS, Europe’s Galileo and China’s BeiDou. The emergence of the CRPA comes just as EW jamming and the electromagnetic spectrum took center stage in the war in Ukraine, and shortly before a U.S. Navy MQ-4C Triton ISR UAV disappeared from flight tracking websites over the Persian Gulf on April 9.
RMP, DIGAR and EPAWSS upgrades for F-15E
Abd confirmed that the aircraft in the photo is assigned to Seymour Johnson AFB, North Carolina. “I’ve seen this feature on a handful of F-15Es so far, most of which are LN tails, but the deployed MO/SJs seem to have the mode,” Abd explained.
For clarity, LN, MO, and SJ tail flashes correspond to the 48th Fighter Wing at RAF Lakenheath, England, the 366th Fighter Wing at Mountain Home AFB, Idaho, and the 4th Fighter Wing at Seymour Johnson AFB, North Carolina, respectively. We reported in mid-February that 14 MO and SJ F-15Es passed through RAF Lakenheath along with 12 F-22s and 12 F-35As as part of the build-up prior to Operation Epic Fury.
The circular shape of the CRPA mounted on the F-15E matches the general design of the system as seen in a simple image search. However, within a circular disk, a CRPA can have between 4 and 16 antenna elements. For example, the CRPA used in BAE Systems’ DIGAR system can support up to seven elements.
Following the DIGAR contract, BAE Systems stated on September 8, 2022 that USAF F-16 Fighting Falcons were the first platform to receive the DIGAR system. “DIGAR uses advanced antenna electronics, high-performance signal processing and digital beamforming (the ability to combine 16 steered beams) to provide better GPS signal reception and superior interference immunity,” BAE said.
SATURN is a next-generation UHF communications standard designed to allow safe and reliable voice and data transmission while preventing jamming and interference. Because of the capabilities it can offer, SATURN is considered a successor to the current NATO standard for Have Quick ECM-resistant radios and secure military communications.
The next-generation Very High Frequency SATCOM Mobile User Targeting System (MUOS) has been selected to replace the existing Very High Frequency Follow-on (UFO) satellite communications system. MUOS is said to offer 16 times greater capacity than UFO SATCOM and provides near-global line-of-sight communications capabilities.
The upgraded MUOS and SATURN can be installed with the Eagle Passive/Active Warning and Survivability System (EPAWSS), designated AN/ALQ-250 in the United States. no way March 2024 pre-recruitment notice In fact, the Air Force Materiel Command (AFMC) has noted that the service is looking to integrate more upgrades into the same aircraft modification line.
The notice scoured the market for potential sources to provide “hands and support for the integration of the Mobile User Targeting System for NATO/Second Generation Anti-Jamming UHF Radio (MUOS/SATURN) into the F-15 Eagle Passive/Active Warning and Survivability System (EPAWSS) modification line.” Notably, BAE Systems is also the main contractor for the EPAWSS programme.
It is unclear whether the DIGAR upgrade is a standalone program separate from the EPAWSS, MUOS, and SATURN lines.
A total of 99 F-15E Strike Eagles are scheduled to receive the EPAWSS modification, which will become standard equipment on the new F-15EX Eagle II. The protection suite will also be integrated into the Japanese and South Korean F-15s.
The first two EPAWSS F-15E Strike Eagles were delivered to the 48th Fighter Wing at RAF Lakenheath in January 2025. The aircraft returned there in May 2023, two years after the upgrade modifications began.
The first F-15E equipped with the advanced EPAWSS electronic warfare system takes off from San Antonio and heads home. @48 Fighter Wing.
This next-generation technology improves pilot situational awareness and ensures the F-15 can meet modern threats. pic.twitter.com/QG8hXi5ba8
— Boeing Defense (@BoeingDefense) January 17, 2025
Additional F-15 EPAWSS-configured F-15Es would have been delivered in the interim.
These aircraft have already undergone RMP upgrades and been converted to APG-82(V)1. In fact, the RMP was completed in 2024 and more than 200 F-15Es received the new radar.
The 389th Fighter Squadron (389FS) at Mountain Home AFB, Idaho, received its first F-15E Strike Eagle equipped with the new radar in June 2014. At the time, the Air Force said MO fighter jets would complete the conversion to the new radar by 2017, with the rest of the base following.
RMPs equipped with the new APG-81 are essential to support future upgrades to the remaining defense, EW and mission systems.
