These small unmanned aerial vehicles (UAVs) can cost as little as a thousand dollars, and are causing problems by their sheer proliferation in numbers. They get in the way of firefighting aircraft, civil and commercial aircraft around airports, and can hamper law-enforcement, to say nothing of invading the privacy of individuals.
We haven't even touched on the potential threats of terrorists using drones to deliver explosives, chemical or biological agents, or conduct surveillance of sensitive public, government, or industrial facilities.
The problems is these drones are small and difficult to detect until they're dangerously close. In June a hobby drone flying over a forest fire in Southern California forced the grounding of helicopters on scene to fight the blaze. The threat of firefighting aircraft colliding with the drone were too great.
Industry and government have started to develop technologies to detect, identify, commandeer, and even destroy trespassing drones if necessary.
Blighter Surveillance Systems in Great Chesterford, England, has demonstrated an anti-drone system, and other companies are working on technologies to control drone access to sensitive or dangerous areas.
The Wall Street Journal published a story last week headlined Next Step for Drones: Defending Against Them that outlines some of the progress that has been made toward developing effective and affordable counter-drone technologies.
One of the technological challenges to counter-drone systems is today's sensitive radar technologies. Many radar systems have been fine-tuned to filter out small targets like birds to reduce clutter and false alarms. These filters can make drones invisible to radar.
Still, there are sensor technologies that have been developed to help helicopter pilots sense and avoid high-tension power lines in their flight paths. These technologies can involve radar, ladar, infrared sensors, or other approaches to detect small targets. A growing number of prototype counter-drone systems should be available within a year.
It shouldn't be long before we see counter-drone technologies integrated into perimeter security systems protecting sports stadiums, nuclear power plants, airports, prisons and military bases.