US government agencies and police forces are working together to develop high-tech systems to bring down rogue drones, say sources.
More than one million drones are expected to be sold in the United States this year, compared to 430,000 in 2014, according to the Consumer Electronics Association and the Federal Aviation Administration (FAA) said last week that US pilots have reported more than 650 drone sightings so far this year compared to 238 over the whole of 2014.
This surge in drone activity has raised concerns that one could hit a commercial aircraft during landing or take-off, or be used as a weapon in a deliberate attack, prompting the authorities to investigate ways to track and disable drones, sources familiar with the matter said.
"We can't shoot it out of the sky. We have to come up with something that's kind of basic technology so that if something happens, the drone or device will just go right back to the operators. It won't crash," one of the sources said.
Police want to be able to take control of a drone, steer it safely away from the public and guide it back to the operators, who can then be identified, said the sources, who were not authorised to speak about the subject. This requires it to be tracked and identified with a receiver and then targeted with an electromagnetic signal strong enough to overwhelm its radio controls.
"You need enough power to override the transmitter. If I just jam it so it can't receive signals, it's probably going to crash. But if I know the transmission codes the drone is using, I can control that object," said retired US Marine Lieutenant Colonel Muddy Watters, an electronic warfare expert.
In an early field test last New Year's Eve, New York police used a microwave-based system to try to track a commercially available drone at a packed Times Square and send it back to its operator, according to one source involved in the test.
The test ran into difficulty because of interference from nearby media broadcasts, but it was part of the nationwide development effort that includes the Department of Homeland Security, the FAA and the Defense Department, the source said.
Asked about the development of counter-drone-technology, the Department of Homeland Security said it "works side-by-side with our interagency partners" to develop solutions to address the unlawful use of drones. Officials with the Defense Department, FAA and New York Police Department declined to comment.
Recreational drone operators are not required to register their machines, obtain training or put identifying features on the aircraft, making it extremely difficult for police to track down rogue operators.
A Reuters analysis of FAA data shows that authorities identified operators in only one in 10 unauthorised drone sightings reported in 2014, while only 2 per cent of the cases led to enforcement actions.
Politicians have raised the prospect of federal support for jamming drone systems and other potential technology solutions, while Senator Charles Schumer, a New York Democrat, proposed this week that drone manufacturers be required to install technology capable of preventing the unmanned aircraft from straying near "no fly" areas such as airports.
So-called "geo-fencing" software could be installed in drones to prevent them from straying above the legal altitude or too close to sensitive sites and drone industry executives say that one possible solution is an industry-wide agreement to include this technology. Chinese drone maker DJI has already released a software update that will restrict flights around sensitive areas.