Nets and high-tech hijackings: Anti-drone systems offer new ways to counter rising threats

Drones have harassed airports and bedeviled local police.

Drones have harassed airports and bedeviled local police. They have trespassed over nuclear plants and prisons. On the battlefield, they can kill.

But aside from shooting down the devices, which may create further danger, there’s often not much anyone can do to stop drones when they pose a threat or wander where they’re not welcome.

That’s beginning to change. Cheap and easily modified, unmanned aerial vehicles have become a part of daily life as well as a tool for governments and bad actors alike — used for intelligence gathering, surveillance, sabotage, terrorism and more. Concerns about their misuse have spurred a technological scramble for ways to stop the devices in midair.

“An adversary can use an off-the-shelf drone they bought for $500 and find out what’s going on at U.S. nuclear weapons bases,” said Zachary Kallenborn, a London-based national security consultant and expert on drone warfare. “China, Russia, Iran: If they’re not doing it they’re stupid.”

Military drones are already potent weapons of war, used to track enemy movements and deliver attacks. But they have become an increasing threat at home, too. And anti-drone systems now hold significant promise for airports, water treatment plants, military installations and public events targeted by drones in recent years.

The rise in incidents involving unmanned aircraft — like the wave of sightings reported last year in New Jersey — has led to more research and investment into the most effective ways of countering drones, preferably while preventing injuries to those below.

Some systems work by firing a projectile to destroy it. Others jam the radio frequencies used to control the drones, causing them to land in place or fly back to their origin. Another approach uses other drones to fire nets at the offending devices.