By Dan Gouré*
Drones or unmanned aerial systems (UAS), particularly small ones, are proliferating on the battlefield. They also pose a growing threat to the homeland. The drones themselves and the tactics for employing them are becoming more sophisticated.
Small drones require different counters than larger ones that resemble aircraft. They are harder to detect, track and engage. Over the past decade, the military has fielded lots of stop-gap solutions. Industry is working on many more, some extremely sophisticated. Now, the Pentagon is trying to bring order out of chaos.
The Pentagon’s newly-established Joint Counter-Small UAS Office (JCO) defines small drones as those in the first three of the five group taxonomy of all military UASs. This means they may weigh as little as a few pounds, with limited range, altitude, and flight times, or as much as 500 pounds, with a roughly 100-mile range and six hour endurance.
Until recently, the world was dominated by advanced military systems such as ballistic and cruise missiles, stealthy manned aircraft, nuclear-powered ships, large armored fighting vehicles, and even large drones such as the Predator and Global Hawk. So, then, what makes the threat from small UASs so concerning?
Small drones can perform missions that used to require manned aircraft or large unmanned aerial platforms. With the appropriate sensor, small UASs can provide high quality ISR. They also can be employed as weapons. This was seen to be the case when ISIS equipped small commercial drones with hand grenades. On a deadlier scale, the U.S. military currently operates several small UASs armed with explosive warheads. The largest of the small drone can carry precision-guided munitions.
As UASs have become more sophisticated by employing artificial intelligence, so have the tactics for using them. The U.S. and China have begun experimenting with so-called drone swarms in which large numbers of small UASs are deployed to overwhelm any defenses or attack multiple co-located targets.
Small UASs pose a different challenge than any other air threat. They fly low, slow, and with small motors that make them hard to detect. Commercially available quadcopters can hover close to the ground, challenging both radar and electro-optical detection systems. Even if their presence is noticed, locating them precisely enough to engage them poses an additional challenge to defensive sensors.
But once located, how should they be engaged? Because small UASs are cheap and can be deployed in large numbers, a defense against them needs to be equally cheap on a per engagement basis. If they are armed and flying over friendly forces or civilian infrastructure, knocking them from the skies can create unintended consequences and collateral damage.
As the threat from drones grew, so did the search for solutions. According to one recent study, there are now over 500 systems on the market. Dozens of systems to counter small UASs have been developed, and a large number are now actually deployed. These range from high-powered rifles, trained falcons, and vehicle-mounted cannons to anti-aircraft missiles, jammers, and even drones designed to hunt other drones.
It is increasingly clear that there is no silver bullet solution to the challenge posed by small UASs. Finding and targeting them will require the coordinated employment of multiple sensors. The same is true for engaging these targets. Proposed solutions involve the use of kinetic weapons, directed energy, jammers and cyber warfare.
The JCO was created to bring order out of the chaos that had marked the counter-small UAS environment. The JCO recently delivered a draft strategy and joint requirements document to the Secretary of Defense. It also selected seven systems as the interim suite of solutions for the joint force along with a single common command and control architecture. One of the most interesting interim solutions is the Marine Corps’ Light-Mobile Air Defense Integrated System, which was recently employed to take out an Iranian drone threatening U.S. Navy ships in the Persian Gulf.
The JCO is tasked to provide a roadmap for the development and fielding of enduring solutions to the small-UAS threat. To that end, the JCO and the Army’s Rapid Capabilities and Critical Technologies Office are developing a systemic approach to identifying and testing the best solutions that industry can offer.
Fortunately, the U.S. aerospace and defense industry has been working on sophisticated answers to the challenge. It is clear that virtually all solutions will require multi-spectral sensing. In that vein, companies have developed a range of solutions for defeating small UASs. For example, Lockheed Martin, Raytheon, and Boeing have laser and high-power microwave weapons that can be employed against a variety of aerial threats. These can target individual drones and may provide the optimal solution to the drone swarm threat. Raytheon has been cleared to sell internationally its vehicle-mounted Coyote 2 rocket-powered interceptor, itself a small drone, with the Ku-band radar as a counter-UAS weapon. The Initial Maneuver Short-Range Air Defense system from Leonardo DRS already has the capability to engage small (Group 1 and 2) UASs; additional sensors, weapons, and other effectors could be added.
Jamming has long been considered an effective means of countering small drones. Many companies include an electronic warfare element as part of their solutions. If the command link between the UAS and its controller can be interrupted, many drones will either land, return to their launch point, or at a minimum veer off course. An alternative that is particularly well-suited for defeating drones operating autonomously is the use of cyber weapons, which will allow the defender to take control of the drone.
The JCO faces a daunting task. Enduring solutions must work for the Joint Force, across a wide range of environments and in fixed, relocatable, and mobile configurations. These systems also must work while not interfering with the operation of friendly forces and their air and missile defenses, sensor systems, and communications networks. They also must be cost-effective against threats that are inherently cheap.
*Daniel Gouré, Ph.D., is a vice president at the public-policy research think tank Lexington Institute. Goure has a background in the public sector and U.S. federal government, most recently serving as a member of the 2001 Department of Defense Transition Team.