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Video Above: Destroying Drone Swarms

By Kris Osborn - President & Editor-In-Chief, Warrior Maven

Are mechanized forces and units of maneuvering soldiers vulnerable to large swarms of mini-drone explosives or surveillance operations suddenly appearing in the air? The U.S. Army is taking measurable and impactful steps to minimize and counter the risk.

Small drone swarms can hit speeds of 60-to-70 miles per hour, and some are small enough to fit in the palm of the hand. Swarms of these can be dispatched to blanket an area with ISR, build-in redundancy so a mission can continue if one is destroyed or even become explosives themselves programmed to detonate upon impact.

They are a unique and pressing threat capable of presenting a new sphere of challenges for advancing ground infantry or armored units. They can of course also threaten Forward Operating Bases and other high-value targets. Newer applications of advanced autonomy can also enable greater flight-path and mission coordination among drones themselves, and they of course build in redundancy such that attacks can continue in the event several are destroyed.

Counter Drone Technologies

These are key reasons why the Army and its industry partners are now testing, refining and upgrading a key number of counter drone technologies and tactical approaches. 

Groups of drones, should they be effectively sensed and “found” quickly, can be jammed, disabled or simply exploded in sufficient time prior to arrival with AI-enabled sensor processing, kinetic effectors such as interceptor missiles and munitions or non-kinetic and less damaging alternatives such as high-powered microwave, EW or lasers.

Drone Swarm

A web of swarming unmanned aircraft systems

Historically, cannon-firing armored vehicles typically tracked and attacked ground targets in a more "linear" force on force kind of mechanized formation. Now, the evolving threat has led Army innovators to refine requirements and build in more multi-domain air-ground kinds of attack possibilities as well. These efforts appear to be showing great success.

“Proximity” Fuse 

One interesting innovation now being improved is the use of what’s called a “proximity” fuse for ammunition fired out of a cannon mounted on an armored vehicle such as a 30mm lightweight chain gun. 

Proximity rounds operate with a built-in sensor able to detonate when in close range of an approaching drone swarm. The fragmentation occurs over a dispersed “area” such that it can destroy a group of targets in close proximity to one another in the air. 

Cannons can also fire air-burst rounds which are pre-programmed to explode at a specific, predetermined point in the air based on a number of measured “rotations.” While both are extremely effective, Army expert weapons developers say proximity rounds are optimal against drone swarms.

“There are pros and cons to proximity, there are pros and cons to airburst, a lot of it depends on what target you're going after. Right? So applications specifically against an unmanned aircraft, you can use both. This is really good for proximity though, because the target my move might be smaller than a faster moving than an armored vehicle or a soldier on the ground,” Maj. Gen. Ross Coffman, Director, Next Generation Combat Vehicles Cross Functional Team, Army Futures Command, told the National Interest in an interview.

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Army industry partners such as Northrop Grumman recently fired off proximity rounds from a 30mm cannon during a live fire demonstration at a Bushmaster Users Conference in Arizona. During the event, a Ford 250 pick up truck mounted with a 30mm chain gun fired proximity rounds at targets in the desert.

Bushmaster M230LF

The Bushmaster M230LF seen here on the EOS R400 Remote Weapon station will work in tandem with the Mobile Acquisition Cueing and Effector (M-ACE) vehicle to defeat drones. The M-ACE platform “cues” the exact target location to the gun truck, which is armed with Northrop Grumman proximity ammunition. When used together, our CUAS capabilities provide precise accuracy to identify, track and defeat moving unmanned systems.

Northrop Grumman Developers describe the proximity round as having an optimal “fire control solution” for destroying drones.

“As soon as the round is fired, the radar on the front of the bullet opens its eyes, and it flies until it sees something. The radar tells the round if the target has moved back a little bit or if it's moving forward so it can initiate more precisely,” Rob Menti, Business Development, Northrop Grumman, told The National Interest during a Bushmaster demo in Ariz.

Airburst Rounds

Airburst rounds, while perhaps less impactful against drone swarms, can also be extremely effective. They often use a laser rangefinder to discern the exact distance of an enemy target in “defilade” and explode right near or just above a specific hidden enemy target. 

An Army scientist once explained that since the speed of light is a “known” fixed entity, and the time of travel to a specific target can be determined, then algorithms can calculate the exact distance. A round can therefore be pre-programmed to explode, for example, over a group of rocks hiding enemy fighters. While they might be less effective against fast-moving targets, airburst rounds offer specific and highly impactful attack options against otherwise unreachable fixed enemy positions.

30mm airburst cartridges

A series of 30mm airburst cartridges fired from the 30mm Bushmaster® Chain Gun® during a recent test showcases the system’s ability to defeat targets in defilade positions. (Northrop Grumman)

For these reasons, Coffman was clear that both kinds of attack rounds will continue to be developed for 30mm and 50mm cannons, among others.

AI-enabled Targeting Technologies

A reason for the rapid maturation of this kind of counter-air targeting may be due to the fast maturation of AI-enabled targeting technologies. 

The Army, for instance, is now having breakthrough success at experiments like Project Convergence using AI-empowered computer systems to quickly analyze gathered sensor information, perform near-real-time analytics to discern target specifics and bounce information off of a vast, compiled database to determine optimal "shooters," "effectors," or countermeasures for a specific attack scenario.

Army M1A2 Abrams tank integrating the FIRESTORM AI

An Army M1A2 Abrams tank participates in training at Fort Benning, Georgia, in January 2020. Army researchers are integrating the FIRESTORM AI-enabled decision-making aid with the Abrams, as well as a host of other systems. Army Sgt. Joshua Wooten

Sensor to shooter time, using emerging AI-capable systems such as the Army's FireStorm, are reducing sensor to shooter time from minutes down to seconds. An AI-system can even compare incoming sensors specifics across a seemingly limitless database of historical instances and tactical scenarios to help determine, for example, if a drone swarm would be countered by EW, a laser or explosive "kinetic" solution. Should a drone swarm be attacked over an urban area, for instance, a laser or EW "non-kinetic" solution might be preferred to minimize explosive fragmentation and potential collateral damage. Other circumstances might require a proximity round or drone-on-drone kind of explosive interceptor.

These kinds of key computer-enabled discernments were being assessed during the Bushmaster Users conference which combined proximity rounds and integrated fire-control with armored vehicle-mounted cannons.

“If a decision is made that you don't want to engage it with a kinetic means, we can immediately turn on our jammer that is integrated. While AESA (Active Electronically Scanned Array) is moving, the system also has a passive RF detection capability. We have both passive and active sensors on the platform,” Menti said. 

Kris Osborn, Warrior Maven President

Kris Osborn, President of Warrior Maven - The Center for Military Modernization