ECRS-Mk2-(Leonardo)
The RAF’s Typhoon FGR4 fighters will receive the ECRS Mk.2 radar which has an integral electronic attack function enhancing the jets’ SEAD capabilities.

Specialist and general media were abuzz in early September with the news that the Royal Air Force’s Typhoon fleet will receive a new AESA (Active Electronically Scanned Array) or E-Scan) radar.

Leonardo is developing the X-band (8.5 gigahertz/GHz to 10.68GHz) ECRS Mk.2. Work is taking place under a $407 million contract (the latest in a series of contracts) awarded to the firm by the UK Ministry of Defence on 3rd September. The ECRS Mk.2 will replace the existing mechanically scanned (M-Scan) X-band Euroradar Captor-M on British Tranche 3 (and perhaps later Tranche 2) Eurofighter Typhoon aircraft.

The original Captor-M was developed by the Euroradar consortium comprising Hensoldt, Indra and Leonardo. Euroradar later developed the Captor-E AESA radar as a minimum change version of the M-Scan Captor radar, combining the existing Captor back end with a new AESA antenna, mounted on a dual swashplate repositioner. This new AESA was developed under a contract awarded to Euroradar by the North Atlantic Treaty Organisation’s Eurofighter and Tornado Management Agency (NETMA). NETMA is responsible for managing the Typhoon programme on behalf of Germany, Italy, Spain and the UK; its partner nations.

Leonardo had design leadership for Captor-E, and BAE Systems had responsibility for platform integration. The resulting production variant, known as the ECRS Mk.0, is the ‘basic’ AESA radar being fitted to Kuwaiti and Qatari Typhoons.

In 2018 the Euroradar consortium was dissolved into two groups: Hensoldt and Indra, and Leonardo. The Hensoldt/Indra grouping is developing a new ECRS Mk.1 radar for retrofit to German and Spanish Tranche 2 and 3 aircraft, and perhaps for the 38 new-build aircraft being acquired under the Quadriga programme. The Mk.1 radar is a minimum-change derivative of the Mk.0. It will be produced by conversion of existing Mk.0 radar sets, by adding a new digital multi-channel receiver and new transmitter/receiver modules developed by Hensoldt. Hensoldt is the design authority for the new Mk.1 radar, and will draw on years of partnership with Leonardo in producing the current Typhoon radar, while Airbus will have equipment design responsibility for integrating the new radar. Leonardo will provide a significant level of support to enable Hensoldt to assume design authority, and will also continue to provide the processor for the German radar.

Leonardo is developing an entirely separate ECRS Mk.2 radar for the British Typhoon fleet. The existence of the two programmes results from the differing operational requirements of the two groups. The UK strongly resisted pressure to join what was once hoped to be a four-nation AESA programme, and insisted that the RAF needed a more advanced radar, which would incorporate extensive electronic attack (EA) and electronic warfare (EW) capabilities.

This led to a divergence of AESA radar development for the Eurofighter.

While the ECRS Mk.0 and Mk.1 radars use the prototype Captor-E X-band active electronically scanned array radar as their baseline, the ECRS.Mk 2 is effectively an all-new design, built on the lineage of the ARTS (Advanced Radar Targeting System) and Bright Adder technology demonstrators, and on the ES-05 Raven radar used on the Saab Gripen NG/Gripen E. Though it shares the same ECRS (European Common Radar System) designation prefix, the new UK-developed ECRS Mk.2 has little in common with previous Euroradar AESA radars.

The ECRS Mk 2 radar does share a common interface with the platform and weapons system, via the German supplied attack computer, and uses the same power generation and cooling, but is not based on Captor technology, instead using a completely new open-architecture radar ‘back end’. From the power supply forward the new radar uses completely new hardware, including what is referred to as a “revolutionary” Multi-Function Array. This will allow the radar to provide traditional air-to-air and air-to-ground, search, track and targeting functions as well as new electronic warfare (EW) and wide-band electronic attack (EA) capabilities.

The ECRS Mk 2 radar makes use of both Gallium Arsenide (GaAs) and Gallium Nitride (GaN) semi-conductors within its array, blending the strengths of the different technologies to cost effectively provide a differentiating military capability.

Leonardo claim that ECRS Mk 2 has significantly more Transmit-Receive Elements than competing AESA radars, allowing it to generate some exceptionally high-powered, focused electronic attack, but also allowing unparalleled passive detection and a very long range. ECRS Mk.2 was designed to ensure that Typhoon will be able to operate in the most challenging contested environments, on its own, and autonomously.

The open architecture of the back end will also enable the rapid low cost development cycles necessary for the radar to be adapted to counter dynamic and developing threats. The concept is that the whole radar will become what is being called ‘mission ware’, which can be changed with the same level of overhead and difficulty as it now takes to change mission data – crucially without having to go back through the safety case every time the software is changed.

The ECRS Mk 2 also has a completely new processor, a new receiver, a dedicated EW receiver and techniques generator, and a completely different system for the antenna repositioner, using a single rotating joint like that developed for Leonardo’s Raven radar for the Gripen E, rather than the double swashplate arrangement of Captor-E. The aircraft will even feature a new radome to support the wide bandwidth that comes with ECRS Mk 2.

Leonardo’s press release announcing the ECRS Mk.2 contract said the radar will have a “world-leading electronic warfare capability … including wide band electronic attack.” This “will equip RAF pilots with the ability to locate, identify and suppress enemy air defences using high-powered jamming.”

Functions

RAF Typhoon-FGR4s already have a potent electronic attack capability in their EuroDASS Praetorian Integrated Self-Protection System (ISPS). The ISPS combines an electronic support measure and radar warning receiver covering a 100 megahertz to ten gigahertz/GHz waveband. Additional systems include a a laser warning receiver (only outfitting Royal Air Force and Royal Saudi Air Force Typhoons); an electronic countermeasures system encompassing a six gigahertz to twelve gigahertz waveband with 50 watts of output power; a Ka-band (32GHz to 38GHz) radar-based missile approach warning system and a chaff/flare dispenser. Other self-protection systems equipping the Typhoon-FRG4 include Leonardo’s BriteCloud RF (Radio Frequency) decoys. This transmits across a waveband of 5.25GHz to 17.7GHz. It provides the aircraft with protection against active radar homing air-to-air/Surface-to-Air Missiles (SAMs) especially those transmitting in wavebands beyond ten gigahertz including Ku-band (13.4GHz to 14GHz/15.7GHz to 17.7GHz) threats.

The key difference between the ECRS Mk.2’s electronic attack role and the jamming functions of Praetorian and BriteCloud is that the latter two are used for self defence: “The ECRS Mk2’s EW and EA capabilities are complimentary to those self-defence capabilities provided by Praetorian,” the company told Armada in a written statement. ECRS Mk 2 promises to allow the Typhoon to enhance the RAF’s F-35 force – not merely carrying additional weapons to the fight, but bringing its own advanced capabilities that will improve the F-35’s survivability and effectiveness. A Typhoon equipped with ECRS Mk 2 will be a very survivable platform, able to operate in the same contested airspace as the stealthy F-35. While the enemy may know that the ECRS Mk.2 equipped Typhoon is ‘in the area’, it will be able to operate with impunity, its pilot not having to worry about his signature, able to carry vast numbers of weapons and “raining down electronic attack and the world’s supply of SPEAR Capability III or SDBs or whatever weapon you want to use, while the fifth gen aircraft is acting as a silent assassin, sliding around the back to slip the knife in!” according to one programme insider.

SEAD

“The EA capability will be used to engage air and ground-based threat systems, such as those which form part of an A2AD (anti-access/area denial) environment.” This hands the Typhoon-FGR4 the means to jam the ground-based air surveillance and fire control/ground-controlled interception radars equipping hostile long-range/high altitude Surface-to-Air Missile (SAM) systems. Taking the Almaz-Antey S-400 Triumf (NATO reporting name SA-21 Growler) SAM complex as an example, this uses the 91N6 (NATO reporting name Big Bird) S-band (2.3GHz to 2.5GHz/2.7GHz to 3.7GHz) 324 nautical mile/nm (600 kilometre/km) instrumented range surveillance and tracking radar and 96L6E (NATO reporting name Cheese Board) C-band (5.25GHz to 5.925GHz) early warning and target acquisition radar with an instrumented range of up to 162nm (300km).

This is precisely the kind of threat that Typhoon FGR4s may face during a future confrontation between NATO and Russia. The S-400 forms a key part of Russia’s Anti-Access/Area Denial (A2AD) posture. While exact details remain confidential it is reasonable to assume that the ECRS Mk.2’s electronic attack function will be sufficient to jam these radars at stand-off ranges beyond the gaze of the radars. Electronic Intelligence (ELINT) gathering performed by RAF and USAF Boeing RC-135V/W Rivet Joint and USAF RC-135U Combat Sent jets in the Baltic may have provided the RAF with details on 91N6 and 96L6E transmission characteristics. Sources close to the Russian air defence community inform Armada that Russia may now deploy up to six S-400 batteries in the country’s European Kaliningrad enclave. These are guarded by up to twelve Almaz-Antey 96K6 Pantsir-S1 (SA-22 Greyhound) combined SAM/Anti-Aircraft Artillery systems The 96K6 is tasked with protecting the batteries against low-altitude air attack. Both VNIIRT 2RL280/E S-band ground-based air surveillance and Phazotron 1RS2-1E X-band (8.5GHz to 10.68GHz) fire control radars equip the 96K6 which can detect targets at ranges of up to 19.4nm (36km). The ECRS Mk.2’s EA mode may also be able to engage X-band like the 1RS2. Although not revealed by Leonardo it would be reasonable to assume that the ECRS Mk.2 will cover a waveband of at least two gigahertz to 18GHz to encompass such threats.

Timetable

Leonardo have revealed that the radar will perform jamming alongside “detection, location, identification, tracking tasks concurrently.” The electronic attack function has already completed trials in an anechoic chamber and in Leonardo’s roof lab at Crewe Toll, Edinburgh, using the Bright Adder testbed.

Though built as a flyable asset, the Bright Adder radar was not actually flown, but it will now take to the air on a Typhoon as part of the ECRS Mk.2 test and evaluation (T&E) effort, with a number of other test radars and the first three production systems. The first ‘Radar Two’ will fly in a Typhoon in 2022, and the T&E fleet will build steadily from there, achieving IOC (Initial Operational Capability) for the ECRS Mk.2 during or soon after 2025.

Once in service the electronic attack function is expected to be regularly refreshed during the radar’s service life “for as long as threats exist, and the system is in service.”

The ECRS Mk 2 radar forms a key part of the UK’s long term vision for Typhoon, forming a cornerstone of the so-called Eurofighter long term evolution. But is also a key building block for future combat air capabilities more widely, and is part of the wider effort to mature key technologies and operational concepts and capabilities for future combat air systems, perhaps including Tempest.

The new radar is also being offered to Italy and to Typhoon export customers, including Finland – where the Typhoon offer is based on alignment with the RAF aircraft standard, including Radar 2. Ironically, in view of its selection of the ECRS Mk 1 for its Tranche 2/3 upgrade and Tranche 1 replacement, Germany could still be a customer for ECRS Mk 2. It has been reported that German defence minister Ursula von der Leyen favoured equipping any new Eurofighters that were acquired to replace Tornado in the nuclear strike and SEAD roles with Radar Two. Moves to split the Tornado replacement buy between the Eurofighter, F/A-18E/F Super Hornet and EA-18G Growler may make this less likely. Airbus has also unveiled a dedicated SEAD variant (the so-called Eurofighter ECR) to meet the LUWES (Luftgestätze Wirkung im Elektromagnetischen Spektrum or airborne action in the electromagnetic spectrum) requirement, with conventional jamming pods.

by Dr. Thomas Withington