NATO’s ground based air defence (GBAD) has made important strides in catching up its rivals lead in countering the forward battlefield air threat.
In June 1944 Field Marshall Erwin Rommel reporting on the German Army’s Normandy post D-Day situation stated that “allied air superiority prevents all traffic…making operations difficult or impractical”. The dilemma directly contributed to his Army’s inability to contain the Allied breakout.
Today’s growing presence of Unmanned Aerial Vehicles (UAVs), the introduction of loitering munitions, cruise missiles, and high-speed low-level helicopters suggest ground forces are facing an increasingly complex challenge in future peer-on-peer conflicts. Just the presence and use of unmanned systems by Azerbaijan against Armenian forces in 2020 replicated the adverse impact on the battlefield as described by Rommel following D-Day. What is clear is that forward ground forces without the capability to counter these aerial threats can, as in 1944, find their battlefield combat abilities seriously diminished and missions compromised.
The Soviet Union and its then client states, recognising the devastating effect air attacks could have against tactical ground forces have, since the 1970s, focused on creating viable air defences. The United States and Western armies are only recently beginning to respond. An effective counter-air capability requires the ability to detect and identify threats, engage, and neutralise opposing air assets, preferability before they can strike. For front-line units accomplishing this task has become a paramount concern.
Threat Detection
Battlefield tactical air defence has traditionally been reactive, providing force protection against enemy air interference with ‘friendly force freedom of action’ (as reflected in the Marine Corps Warfighting Publication – MCWP3-22 Chapter 3). This is at least partly due to the difficulty in detecting aerial threats, made even more difficult when facing small unmanned aerial vehicles operating at low level hidden by terrain and vegetation, as well as loitering aerial munitions that can remain out-of-sight attacking suddenly on command. The objective today must be detecting and identifying aerial targets before they can come to bear and rapidly acting to neutralise the threat. This must be accomplished facing both passive and active counter-air defence measures by the opponent.
Radar has been the mainstay of air threat detection with the latest systems exhibiting increased range, resolution, and multi-mission target tracking. These systems are classified as long, mid, and short range. The long-range radar offers wide area deep coverage with ranges often beyond 216 nautical miles (400 kilometres). The latest incorporating Active Electronically Scanned Array (AESA) technology are capable of detecting tracking multiple contacts with high fidelity. These include Northrop-Grumman’s AN/TPS-80 G/ATOR being fielded by the US Marines, Raytheon’s US Army LTAMDS (Lower Tier Air and Missile Defence Sensor), and Lockheed-Martin’s TPS-77 in the high/medium defence role. These provide air surveillance and counter-fire target acquisition while GATOR is also an air-traffic control system.
SAAB’s Giraffe is a family of G/H agile multi-band and AESA radar. Its latest Giraffe long range candidate is its 8A. Capable of heavy truck mounting 8A is a 253nm (470km) range 3D surveillance radar able to track aircraft, missiles, and small UAVs. It incorporates electronic counter countermeasures automatically selecting least jammed frequencies and intermittent or randomly transmitting.
The size of these long-range radar, many of which are trailer mounted, make them more difficult to relocate quickly if targeted or to allow them to keep up with mobile forces. They therefore are generally placed well to the rear of the battle area. This and blocking terrain can impact on their ability to offer full coverage for forward and manoeuvring forces.
Medium range radar offers more local surveillance but are generally more mobile and favoured for supporting short-range defence and to fill coverage gaps. They can be placed closer to but still behind forward combat elements. The US Army trailer mounted Sentinel AN/MPQ-64 phased array radar used in this role is being upgraded with AESA technology. A Lockheed-Martin spokesperson shared that: “The MPQ-64A4’s move to AESA adds rocket, artillery and mortar detection as well as simultaneous tracking of these and air threats enhancing its battlefield utility.” The company receipt of an order for five A4s in October 2021 reflects the US Army’s push to improve its forward air-surveillance capabilities. SAAB’s Giraffe 4A offering true 3D multi-role air and weapon locating capability to 21.5nm (40km) is another battlefield multi-role system. It can be ground or vehicle mounted and deployed by only two soldiers in ten minutes and displace in five. Another SAAB option is the Giraffe AMB with 16nm (30 km), 32nm (60km), and 54nm (100km) range bands for air including hovering helicopter, UAVs (due to its ELSS enhanced low, slow, and small function), and fast missiles, as well as, indirect shot, and ground target detection. In its vehicle mounted elevating mast version it can displace in six minutes and be operational in ten.
Short range radar surveillance is for relatively close-in and battlefield applications. It often offers not only air, ground and shot detection but weapons direction and target hand-off. The Multi-mission Hemispheric Radar (MHR) from RADA Electronic Industries as selected for the Stryker vehicle IM-SHORAD manoeuvre short-range air defence system is on-the-move capable. Each fixed panel antenna covering 90 degrees can detect a Nano UAS at 2.6nm (5km), medium UAS or helicopter at 12.4nm (23km), fighters at up to 18.3 (34km) and even ground vehicles and people at 12.4nm (23km) and 5.4nm (10km) respectively. SAAB offers its Giraffe 1X for short-range. The 1X offers air surveillance including the small UAS, hostile fire locating, and ground target detection and tracking to 40.4nm (75km). With a top load of under 220 pounds (100 kilograms) – and total system weight of 330lb (150kg) it can be placed on elevating masts to surmount obstacles or mounted on light vehicles or light trailers. 1X is ideally suited for point defence and filling gaps in long-range coverage. Plus, its on-the-move search capability supports forward deployment including covering of manoeuvring forces.
In the past ground surveillance radar focused on ground targets. However, with the increased presence and threat of low level UASs and other low altitude threats attention is begin given to their use here as well. Generally, small, and portable they can deploy with forward units. SRC’s AESA 3-D SkyChaser, for example, is 75lb (34kg) and can be tripod, mast, or vehicle mounted. It can operate on-the-move and detect vehicles at 17nm (32km), people at 6.4nm (12km), and UAVs. Thales’s Ground Observer GO 20MM X-band 3D is both man portable with five minutes set up or light vehicle compatible. It simultaneously detects low level air targets as small as a micro-UAV 2nm (4km) to vehicles and helicopters at up to 8nm (15km). It includes automatic target classification.
These systems also lend themselves to being co-located with high-resolution electro-optic day and thermal cameras, thereby, providing integrated detection, tracking, identification, and targeting/kill in a single package. Northrop-Grumman’s M-ACE (Mobile – Acquisition, Cueing and Effector) does exactly this using a AESA 3-D, two EO/IR cameras while adding a RF signal detection. Presented as a counter-UAS solution, company representatives indicate that it is capable of detecting and tracking any ground/low level target and cueing appropriate guns and/or missile effectors.
The increasing presence of electronic signals detection and locating capabilities on the battlefield raise the danger that actively transmitting sensors, like radar, will be identified and neutralised. Optronic detection and targeting such as Infra-red search and tracking systems have the benefit of being fully passive sensors. Rheinmetall’s Fast Infrared Search and Track (FIRST) and HGH Infrared Systems’ Spynel continuously scan 360 degrees detecting the IR signatures or temperature difference between the surrounding of contacts. Then processing the signal, they can identify, classify, and provide an alert to potential threats. Fully passive with detection ranges of 0.8nm – 1.6nm (1.5km – 3km) for a small UAS to 6.4nm (12km) for low level aircraft they will also detect and locate ground targets. The systems, thereby, contribute to an integrated ground-air situational awareness.
Counter-Air
Counter-air effectors are largely missiles with either external guidance, self-guidance, or a combination of both. At the battlefield level these include mid or medium range and short-range forward systems. The former has engagement ranges in excess of 13.4nm (25km) with the latest versions offering self-contained with tracking and engaging integrated on the same platform. Many are able to address a broader range of threats including low-observables, high-speed missiles, drones, and precision air-to-ground weapons. Though deployable they are, however, designed for operating from stationary positions. The British Army’s newly fielded Sky Sabre which uses MBDA’s Common Anti-Air Modular Missile (CAMM) with an active seeker prompted by the Giraffe ABM is one of the latest examples. Derived from the naval SeaCeptor adoption of the system by Poland is also anticipated. MBDA is also finalising a 24nm+ (45km) + Extended Range version.
Dynetics’ Enduring Shield is another ground-based weapon system has been selected to fill the US Army’s Indirect Fire Protection Capability (IFPC). Using the proven AIM-9X Sidewinder missile, though Ronnie Chronister, senior vice president for weapons technology, indicated ‘with a modular, open architecture we are basically missile agnostic’. Thus, the system has potential versatility to address a wider range of threats including ground targets with the appropriate ordnance. The current design pallet or mounted with the later offering tactical mobility using the Sentinel radar.
Kongsberg’s NASAMS, developed with Raytheon, is a widely fielded mid-range beyond visual range surface to air missile system employed by fifteen countries. Hans Christian Hagen, vice president Business Development explained, “Its modular design allows use of AIM-120 AMRAAM Extended Range for longer 16nm (30km+) engagements and AIM-9X-2 Sidewinder for close in. It uses the Sentinel radar with the NASAM 2 employing the F1 X Band 3D model. Batteries, which can be truck, light vehicle, or pallet mounted, include a MSP500 Electro-optic tracking and control vehicle allowing passive engagements.” Kongsberg also offers a multi-domain fire control centre that will manage not only the NASAM and other counter-air assets but also its NSM ground strike missile.
These medium systems can provide a battlefield ‘air space overwatch’ yet close coverage falls to shorter range tactical systems.
Michael Hoglund, head of Saab Bofors Dynamics missile system marketing, explained “it has become evident that (air) protection of battalions on-the-move is a weak link capability gap in many forces”. RBS70 NR, its latest, offers a tactical counter-air solution tailored to this ground battlefield. He added “close-in solutions must have multi-target capability” which RBS70 provides. The system teams the Giraffe 1X radar for surveillance with the laser-beam riding Mach 2 Bolide missile to tackle targets to 4.8nm (9km). Both are either tripod or vehicle mounted with the later also dismountable in, for example urban situations. Advanced cueing, auto-tracking, IFF and high-resolution thermal imaging assure 24/7 engagement that is fully passive and essentially ramming proof. According to Hogland,” The Mobile SHORAD remote weapon station vehicle version offers on-the-move manoeuvre coverage against the complete range of battlefield threats from fixed wing and helicopters to UAS’s and cruise missiles.” Bolide’s proximity or impact fused shaped charge surrounded by 3,000 tungsten pellets is effective against even armoured aircraft and ground targets including light vehicles. These features of the RBS70 NR contribute to its application to the dynamics of the new battlefield.
One of the latest entries is the US IM-SHORAD provided by Leonardo DRS. It could, in fact, be better viewed as a multi-role weapon system in that its modular unmanned weapon station (Moog’s RIwP) mounts not only four Stringer IR seeking missiles, but two Longbow HELLFIRE ground attack missiles, a Northrop-Grumman XM914 30mm auto-cannon and M240 medium machine gun. Integrated on the Stryker A1 wheeled combat vehicle it can keep-up with manoeuvring forces. Four RADA 4D ASA pulse Doppler Multi-Mission Hemispheric Radar (MHR) can detect and track targets from micro-UAVs to rockets, aircraft, people, and vehicles. An MX-GCS Electro-optic/IR sight provides for passive target identification and engagement. It, thus, can detect and with its missile/gun mix address not only a full range of airborne but ground threats as well.
Man-Portable Air Defence Systems (MANPADS) offer counter-air to the dismounted force. They can be carried and fired by a single operator and are self-guided. The FIM-92 Stinger produced by Raytheon, one of the most well-known, in its latest 92J version uses a dual IR and UV seeker, proximity vs. impact fuse to address the UAS, and IFF (Identification Friend or Foe). It has a target engagement capability of around 4000 m but must rely on either visual target acquisition or external vector cueing. The British Thales Starstreak uses an entirely different approach with (like RBS70) dual-laser beam guidance of a Mach 4 missile containing three explosive tungsten “darts” with a range of 7000m. It has benefits of being immune to IR or RF countermeasures and homing missiles and has proved effective against ground vehicle targets. Starstreak launchers can also fire the recently (2021) introduced Lightweight Multi-role Missile (or Martlet) with IR terminal homing and laser proximity fuse effective against aircraft, UAS, and ground targets. These properties find the Martlet used with Starstreak in the Royal Army Artillery air defence batteries.
Guns are without question the most prevalent weapon system in forward combat forces. Advances in target acquisition and particularly ammunition lethality may well hold the key to countering the forward air threats. Robert Menti Precision Weapons Business Development at Northrop-Grumman explained “the significant multi-target lethality of proximity fused ammunition and the enhanced accuracy of guided gun fired projectiles promise a previously unachievable order of magnitude in round hit and kill engagement capability especially in calibres of 30mm and above opens the possibility for effective and efficient neutralisation of the rising new low-level air threats.” This has been demonstrated with its new XM1211 proximity fused ammunition of the 30mm X 113mm gun. Menti shared “The gun with proximity ammunition directed by its M-ACE (Mobile Acquisition Cueing and Effector) was able to regularly achieve single round kills of small UASs in live fire exercises, thus, reliably neutralising this threat with standard on-board weapons.” Thus, the number of systems able to actively execute a counter-air role are increased multi-fold thereby being better able to respond to its front-line challenge.
Future Challenges
A complication to ground counter-air efforts may be the potential large-scale employment of loitering munitions. Equipped with radar homing seekers these could be positioned to lock-on and ride signals targeting actively radiating sensors. In response additional attention must be given to air defence system mobility. The ability to displace periodically and rapidly has become increasingly critical to survival. In addition, air-defence systems must have either inherent ability to engage and destroy these small aerial platforms or be supported by other counter-air that can. The discrete nature by which the UAS can operate and observe also demand through use of camouflage and concealment to reduce the possibility of being located and engaged.
Given the relative simplicity and proliferation of unmanned aerial systems and munitions, in particular, as well as anticipated enhancements in the speed and manoeuvrability of low-level next generation helicopters the traditional approach to air defence may well prove inadequate. The disbursed nature and potential omnipresence of these threats can, in the forward battle area at least, necessitate a much broader and integrated effort to successfully counter these air threats. This could include not only dedicated air defence assets but also broader local counter-air detection and both direct effectors within front-line forces.
by Stephen W. Miller
