Imagine you are an infantry platoon leader, moving with your soldiers in a tactical formation toward your objective. Suddenly, indirect fire is raining down on your position. You have a plan to react to indirect fire, and you order your formation to execute the plan. Your soldiers are well trained and well led by their capable squad leaders, and they start to move, immediately and rapidly, from the impact area. But as you move, you realize the indirect fire is walking with you—your soldiers can’t escape it. What you haven’t realized is that there is a small unmanned aircraft system (UAS) observing your movement, allowing the indirect fire to follow you and your soldiers through the woods.

Now imagine the same scenario, except this time you have a mobile counter-UAS (C-UAS) system that can track and shoot UAS on the move. Once again, your platoon is engaged with indirect fire. And once again, your platoon has a plan and executes it on your order, Your light, maneuverable C-UAS vehicle can move with you, detect the UAS observing your platoon’s movement, and neutralize it. Within a matter of seconds, the indirect fire ceases. Your platoon can safely regroup and continue mission.

Because of the C-UAS vehicle, traveling with and ready to support the platoon, the second scenario leads to mission accomplishment. Unfortunately, the first scenario is much more likely for Army small units today. C-UAS systems currently used are static or only semimobile, meaning they cannot move when C-UAS systems are operating. These systems proved sufficient during Operation Inherent Resolve—as we experienced while integrating airspace and countering UAS threats in support of the operation. But they will not fit with maneuver units’ mission sets in large-scale combat operations. For that environment, the Army needs a truly maneuverable C-UAS platform for light maneuver units. This platform must be capable of detecting and kinetically or nonkinetically engaging UAS threats on the move and light enough to be air-assaulted or air-dropped from the back of fixed-wing aircraft. And it must be able to counter both sides of the future UAS threat coin: on one hand, increasingly affordable UAS will be fielded in growing numbers, potentially even as swarms, and must be engaged with electronic warfare (EW) effectors; on the other hand, there is the prospect of increasingly sophisticated UAS completely resistant to EW that may therefore be best neutralized through kinetic interception.

With this in mind, what might an appropriate platform look like? Although components of an optimized system would need to be procured, many of them are already in service with the Army and could be adapted to meet future C-UAS needs while allowing for future innovation.

Vehicle Platform

Potential vehicles that could form the foundation of a light, maneuverable C-UAS system include:

Most of these vehicle platforms are just beginning to be fielded by maneuver units throughout the Army including the 101st Airborne Division (Air Assault). Depending on the final gross vehicle weight, some may be better suited than others for a C-UAS vehicle with air-assault or low-velocity air-drop capability. Ideally, this vehicle could accompany dismounted troops as close as possible to their objective area. Then it would remain close enough to provide protection while the dismounted soldiers conduct their tasks on the objective area.

Weapons and Effectors

C-UAS Air-Burst Weapon

A 25-millimeter or 40-millimeter grenade launcher with “smart” ammunition could be specifically tailored for C-UAS engagements. The projectile would detonate in flight, one to three meters before the UAS target. The range would be calculated by a laser range finder built into the scope or sight system. Upon pulling the trigger, a three-to-five-round burst of projectiles would fly toward where the UAS was predicted to be located, then explode at and around that location. The burst would create a cloud of shrapnel in case the UAS changes direction or speed. The shrapnel from the explosive would neutralize the UAS propulsion or flight control systems.

Electronic Warfare Effectors

An EW system is necessary to jam UAS signals. The Titan RF system with an amplifier, for example, may be well suited to disrupt or degrade small UAS. Any EW system included on the vehicle would not have to be co-located with or mounted on the platforms kinetic weapons. The proposed effective range for this system is greater than five kilometers.

Larger UAS Threat Engagement

An option to engage larger UAS kinetically is the FIM-92 Stinger Missile, which could be used to defend against any UAS threats below fifteen thousand feet with a large enough heat signature. Due to the Stinger’s backblast area, the weapon would have to be mounted slightly above other systems on the vehicle and only operate within certain degrees of freedom relative to those other systems. This could reduce the need for a dedicated MANPADs (man-portable air defense system) operator. The effective range for this system is four kilometers.

Distance- or time-defined programmable detonation air-burst grenade rounds would be less expensive per munition and engagement than firing radar-guided missiles or hundreds of high-caliber munitions at UAS threats. Low-cost munitions and compact firing systems are an answer to system fatigue and munition supply constraints that currently limit C-UAS deployment in combat theaters.

A heavier solution for target acquisition and engagement could incorporate a system like the Common Remotely Operated Weapon Station (CROWS). A system like the CROWS could be a well-suited firing platform in conjunction with a remote-controlled vehicle platform like the RIPSAW. A system with these capabilities is still recommended to have man-in-the-loop engagement control to prevent fratricide of friendly or neutral UAS.

Detection

Before engaging UAS, either kinetically or nonkinetically, the C-UAS platform must first be able to detect UAS. This could be done passively or actively, but the detection capability will also be dependent on a reliable power source.

C-UAS Detection System Power

An UPS (uninterrupted power supply) battery pack that provides electricity for four hours or more with a tactical quiet vehicle-mounted generator should be used to maintain noise discipline. The generator would supply power to C-UAS systems while the vehicle is moving. The aim should be for the generator to provide eight hours per full tank of fuel to supply power for C-UAS systems and charging the UPS battery pack. The power output required of the generator is probably between three and ten kilowatts. The UPS battery pack would primarily be used while the generator is shut off. This design course of action increases unit survivability by reducing noise signature from combustion engines or generators near the objective area.

Passive-Active Combination Detection System

Passive radars could be used to detect UAS by measuring the change in electromagnetic frequencies made by the motion of a potential UAS. That detection must occur amid a wide range of commercial electromagnetic waves already present in an area of operation. Common sources and types of electromagnetic signals present in areas with infrastructure include Wi-Fi, cellular, civil radio and television, commercial satellite communications, satellite PNT (positioning, navigation, and timing), civil air radar, and weather radar. An excellent attribute of passive radars is that they do not reveal the observer’s position because they do not emit radiation. This style of detection may be degraded in areas where commercial electromagnetic signals are not constantly present or in a scenario where sources of electromagnetic radiation do not have electricity.

Another sensor form of detection utilizes light detection and ranging, or lidar. It works by emitting and receiving laser pulses of nonvisible light that reflect off physical objects. The reflected light is received by the sensor and is converted to create a digital image of that object. Lidar could be used in conjunction with a passive radar to create high-confidence air tracks at short range. Lidar is commonly used on automobiles in the United States to detect other cars, pedestrians, or obstacles in a roadway. When used for this purpose, Lidar currently has an approximate range of 250 meters while the vehicle moves.

A system that fuses acoustic and optical sensors—multimodal unmanned aerial vehicle 3D trajectory exposure system (MUTES)—was tested at a distance of 480 meters by Siyi Ding, Xiao Guo, Ti Peng, Xiao Huang, and Xiaoping Hong, who published the results of their test in 2023. The conclusion of their report read:

Our results demonstrate that MUTES, which integrates a 64-channel microphone array, a camera, and a lidar, can provide wide-range detection (90° × 360°) and high-precision 3D tracking for UAVs [unmanned aerial vehicles]. A coarse-to-fine and passive-to-active localization strategy software was implemented in MUTES, with a well-designed microphone array capturing acoustic features and estimating the coarse position of the sound source, and the optical modules being used for further verification and tracking. Additionally, we trained an environmental denoising model to extract drone acoustic features, overcoming the drawbacks of traditional sound-source-localization approaches. A Kalman filtering algorithm for the fusion of three sensors proved to be effective and achieved the accuracy of RTK [real-time kinematic]. In terms of both hardware and algorithm, MUTES represents an innovative multimodal detection and tracking system.

This demonstrates a combination detection and tracking method of UAS can be effective. Future system combinations could use passive radar, Lidar, camera, or acoustic sensors.

Active Radar Option

An active radar capable of detecting group 1-3 UAS (the categories of the smallest systems) while moving is ideal to be prepared for future threats. The RPS-42 MHR, used with the M-SHORAD Stryker platform may be suitable for this vehicle. This would include multiple radars fixed at different points of the vehicle to provide real-time detection, early warning, and engagement capability for the maneuvering company or platoon. This could also allow for tracks to be pushed over a joint force tracker such as Link 16 to adjacent units and higher echelons. Optimally, the proposed detection range for this system is fifteen to twenty kilometers.

Positive Identification Enhancers

Multiple identification capabilities are highly recommended for the human-in-the-loop operator to identify UAS and prevent fratricide. Thermal and night vision are also necessary due to probable hostile threat windows and friendly maneuver operation timelines. The following systems have shown to improve soldier lethality with air defense systems: thermal sight, night vision, laser range detector for air-burst grenade programming, and a friendly UAS IFF (identification friend or foe) interrogator.

Network Connectivity

Tactical SIPRNet (Secure Internet Protocol Router Network) connectivity on the move would allow this system to send and receive air tracks, which would help filter out unknown air tracks. Furthermore, this would help with communication between multiple systems, making it easier to decide which system on the battlefield has the highest kill probability.

A mobile broadband kit or Starlink could be used to obtain connection to a tactical SIPRNet,. One Starlink system, one wireless router, one KG-175D TACLANE, two PacStar switches, and one four-port router could be configured to provide this capability, with all of the components fitting in a medium-sized rucksack. This network, in conjunction with a Forward Area Air Defense laptop, would allow tracks to be uplinked from the detection sensor on the light, maneuverable C-UAS vehicle to adjacent units and the higher command while also enabling tracks to be downlinked from higher echelons. This capability provides two functions: first, it provides commanders quick notice of air threats around their platoons or companies; second, it would provide even earlier warning to maneuver elements of threats in the airspace.

If these capabilities were packaged into a single vehicle light enough to be sling-loaded by a helicopter, detection could occur as far away as twenty kilometers, EW engagement at more than five kilometers, and kinetic engagement within two kilometers. This would allow crews to see tracks approaching their positions and have enough time to warn adjacent units and their leadership, and then engage targets with EW and kinetic fires on the move. A lightweight solution like this could also provide advanced C-UAS capabilities to remote areas where a helicopter is the primary mode of entry.

To be sure, until such a system is built and fielded, the discussion remains entirely conceptual. But if the Army makes it a priority and works toward a light, maneuverable C-UAS vehicle that consumes minimal fuel and electricity, then it could be exactly what the platoon leader from the opening vignette needs to protect US soldiers from constantly evolving UAS threats and accomplish the mission.

First Lieutenant Iain Herring is an air defense artillery officer and assistant S-3 for the 2nd Battalion, 44th Air Defense Artillery Regiment at Fort Campbell, Kentucky. He holds a bachelor of science from the United States Military Academy. Herring deployed as an indirect fire protection capability platoon leader to the Middle East to conduct C-RAM and C-UAS activities supporting counterinsurgency.

First Lieutenant Gavin Berke is an air defense artillery officer and an air and missile defense operations officer for the 101st Airborne Division at Fort Campbell, Kentucky. He holds a bachelor of arts from Temple University. Berke deployed as an indirect fire protection capability platoon leader to the Middle East to conduct C-RAM and C-UAS activities supporting counterinsurgency.

The views expressed are those of the authors and do not reflect the official position of the United States Military Academy, Department of the Army, or Department of Defense.

Image credit: Sgt. Henry Villarama, US Army