drone detection via radio waves

Countering drones via radio frequency

As inexpensive unmanned aerial systems become more popular, so too do counter-drone systems that can neutralize the devices to protect critical installations or assets. 

While some companies use a variety of passive and kinetic measures for countering UAS, Alion Science and Technology Corp. relies exclusively on passive measures -- either to return an aircraft to where it came from or to commandeer the drone and force it to land at a safe location. 

Exactly how the technology commandeers and deflects drones in flight is Alion’s “secret sauce,” the company’s lead developer of the platform, Bill Senich, told GCN. Because of patents pending on technologies associated with the counter-UAS system, the company was unable to provide specific details. Senich did say, however, that the system is still being tested and won’t be ready for commercial sale for at least another six months. 

According to a company whitepaper, the solution uses a four-pronged approach to countering unwanted incoming drones: detect the presence of an incoming aircraft, block the connection of the UAS to its operator, establish a new command and control link to the UAS and finally, fully control the UAS to send commands for a graceful landing. 

Unlike many counter-UAS systems that use radar detection, the Alion system detects incoming drones primarily by their radio wave emanations, although it could be deployed with a radar detection system.  Based on the type of aircraft detected, the system can make a proper determination of how to engage it, Senich said. 

The system can also be designed with as much or as little autonomy as desired; however, in a flight safety scenario, Senich said, it is important to have a human in the loop to make the final call on how to engage an incoming aircraft.

So far Alion has only tested the system’s detection at a distance of 500 feet; however, the goal is for a range of 1 to 1.5 miles so that the system can be deployed on an airport approach path or at an airport perimeter. 

The system has also been demonstrated in a variety of environments, but the key will be working out the deployment scheme.  One of the outstanding issues, Senich said, involves antenna placement and direction for optimal detection.    

About the Author

Mark Pomerleau is a former editorial fellow with GCN and Defense Systems.


  • business meeting (Monkey Business Images/Shutterstock.com)

    Civic tech volunteers help states with legacy systems

    As COVID-19 exposed vulnerabilities in state and local government IT systems, the newly formed U.S. Digital Response stepped in to help. Its successes offer insight into existing barriers and the future of the civic tech movement.

  • data analytics (Shutterstock.com)

    More visible data helps drive DOD decision-making

    CDOs in the Defense Department are opening up their data to take advantage of artificial intelligence and machine learning tools that help surface insights and improve decision-making.

Stay Connected