As global demand for small drones has rapidly increased over the past 5 years, so has the concern for the privacy they are perceived to invade and the safety norms they are perceived to violate. This concern has been elevated to downright anxiety with the recent revelation that ISIS has been increasingly utilizing off-the-shelf drones, purchased via the internet. First used as a method for conducting reconnaissance and recording terror attacks from the air to be displayed on social media outlets as propaganda, drone use by insurgents has quickly expanded to dropping improvised explosive devices (IEDs) on US military and other counterinsurgent forces. 

Cheap, consumer drones are also seen as a threat to domestic government interests as well as several commercial businesses. Sensitive sites such as nuclear power plants and military bases can be easily monitored by anyone with the will to launch their flying camera into restricted airspace. For-profit companies worry that “bad actors” could launch drones to covertly conduct corporate espionage by spying on operations from the air. Owners of large stadiums and sponsors of mass public events are becoming increasingly anxious that drone operators could either organize airborne attacks or, worse in their eyes, provide live video to an online audience that generates no revenue.

In response, dozens of companies have established a nascent, and increasingly competitive, market by developing systems that provide a defense against unsolicited drone intruders. These anti-drone systems, commonly referred to as counter unmanned aerial systems (C-UAS), utilize a wide range of technologies to deter, or defeat, this new and expanding threat.

Detect, Identify, Track, Mitigate

There are several approaches for describing C-UAS functionality but Detect, Identify, Track, and Mitigate seems to cover all scenarios. Most systems are not designed to accomplish all 4 tasks. In fact, the systems that can accomplish all 4 steps are almost distinctly relegated to use by governments, or the militaries, because of legal limitations when using certain technologies in a public arena. For instance, Battelle’s DroneDefender, a handheld radio frequency (RF) disrupter, is currently only offered for sale to the US government.

First, a C-UAS must detect a potential threat. The most common detection methods include the using radars, RF detectors, acoustic sensors, electro-optical (EO) imagers, lasers, thermal/infrared (IR) cameras, or a combination of sensors. Each sensor type has advantages and disadvantages driving most C-UAS developers to utilize a multi-layered approach for an optimal spectrum of detection. Historically, these detection methods were not developed to locate low-flying aircraft with small radar cross-sections (RCS) because there was not an associated threat profile. Therefore, C-UAS developers have been adapting existing and/or developing new technologies that specifically search for small RCS objects that fly low and slow. As part of detection, the system must also “recognize” that the target is a machine and does not exhibit biological movements, like a bird would. The ability to recognize reduces the possibility of false alarms. 

Basic systems will provide an alert via email or text after a positive detection is made but more advanced systems can actually identify the type of drone and state-of-the-art systems can even analyze payloads to better assess the threat. Identification of the drone type can be accomplished in several ways. Systems using acoustic sensors rely on a database of known drone sound profiles. Systems that utilize RF can identify drones by using the same information passed to the controller, if the drone is being flown remotely. However, this can require operations that may be illegal since they likely entail gaining unauthorized access to a Wi-Fi computer network. Some companies even advertise the capability to use RF for pinpointing the drone controller location so law enforcement agents can apprehend the remote operator. The most sophisticated systems utilize a slew-to-cue capability where, once a drone threat is detected, an EO/IR camera focuses in on the target. This allows a human or machine to identify the drone type visually and provides the ability to analyze any payloads.

Tracking can be accomplished by any of the commonly used C-UAS sensors, but each has its pros and cons. For instance, radars can track targets at great distances but they don’t work well in urban environments and are relatively expensive. Conversely, acoustic sensors are inexpensive but have a limited range. The ability to track a potential threat becomes invaluable in an environment where laws prohibit frequency jamming or interruption. Keeping track of the target allows the information to be passed to agencies that have permission to engage. Tracking is also important when considering multiple targets. The more targets a C-UAS can track, the more demand it will generate as swarm technology expands the small drone threat in the future. 

Finally, C-UAS aim to mitigate small drone threats. Mitigation can be kinetic or non-kinetic, however, kinetic mitigation, or destroying the drone with some sort of projectile, is generally not an option in the commercial environment. Techniques for mitigation are numerous and most have legal considerations. RF can jam or overwhelm drone control frequencies making the aircraft land or return home. Some C-UAS can even take control of drones. But many regions of the world have laws against these types of actions. There are guns and drones that fire nets designed to entangle intruding drones causing them to fall to the ground. However, in the US, it is illegal to shoot down anything defined as an aircraft and the Federal Aviation Administration (FAA) has included drones in the definition of aircraft. Determining acceptable methods for mitigating small drone threats will continue to be a challenge as the regulatory and threat landscapes change.

C-UAS Market

The C-UAS market is still relatively nascent, but growing rapidly. There were about 20 companies, mostly in the defense sector, involved in the market 2 years ago but that number has blown up to over 90 companies, and is still expanding. There have been a slew of recent sales, both in the defense and commercial sector. Companies like Syracuse Research Corp. (SRC), Battelle, Aveillant, Dedrone, Droneshield, Blighter/Liteye, Black Sage (in partnership with SpotterRF), and IAI have all won contracts for their C-UAS systems. Analyzing these sales reveal that market revenues for C-UAS equipment is likely in the $500 million to $1 billion dollar range annually and poised for double digit growth over the next several years. Competition is fierce and more market entrants seem to arrive weekly.

And while the market for drone defense is rapidly growing, an even newer market for circumventing anti-drone systems is emerging. This “hardening” of drones to make them less susceptible to C-UAS includes technologies such as anti-jammable GPS antennas, unhackable operating systems, and passive noise reduction. We are only at the beginning of the drone/counter-drone cat-and-mouse game.

Conclusion

C-UAS is a nascent market that will experience significant growth over the next several years. Systems that utilize more than one sensor type will lead the market because they are best suited for countering future threats, the most urgent being drones that are sent in swarms and guided by methods that do not require the emission of radio signals. As it grows, expect the C-UAS market to mirror the commercial UAS market in many ways with more strategic partnerships, small companies struggling to stay in business, and an emergence of 2-3 top companies that have the best and most cost-efficient C-UAS for passive detection, legal mitigation, and the capability to easily upgrade and integrate with existing security systems.