Can drones be detected by radar? A related incident happened at White House grounds. A federal worker crashed his drone at white house grounds. The incident attracted much interest regarding the capability of White House air defense system should someone want to use such a small drone to cause trouble. Although this person didn’t have bad intentions, but someday someone will. So, how does the U.S Secret Service—or others tasked with overseeing air defense be able to detect small drones?
There is a notion that small drones are hard to detect by radar. Kelly, the CTO of DeTect says this is not entirely true. Although he admits it is true you cannot detect a small drone with ordinary radar, air security companies like his have been building systems capable of doing just that. The challenge lies not in detecting the elusive radar incoming signals but in telling the difference between a small drone from the birds that the radar will also detect.
Measuring the Motion of the Targets
It is truly possible to tell the difference between detection of a small drone from a bird by evaluating the movement of the targets and other elusive aspects of each radar return. This would be useful with the help of machine intelligence. Machine intelligence would help tell the difference by automating the mechanism of detecting any sources/targets that don’t measure up to par with what you would presume to be a bird or other source of radar muddle.
Detection by Distinctive Sound Drones Make
DroneShield, a company based in Washington, D.C., uses a system that detects nearby drones by distinctive sounds they produce. But this brings some challenges. For example, detection may not work in urban environments where there is lots of noise around. Most microphones only listen well at 25 to 50 feet, so, because of the ambient noise in urban environments, any audio detection would be rendered useless. Also, wind noise can make it very difficult for the microphones to perform optimally. Furthermore, such a system would not be able to detect a drone programmed to fly unpowered when about to reach its target.
Detection via Radio Signals
Small drones can be detected via radio signals that some of them, or their controllers, produce. But that wouldn’t work if a drone is programmed to fly without radio uplinks or downlinks.
Small drones can be detected via video, but with some limitations. Although cameras can see out to about 350 feet, it can be difficult for the camera telling the difference between birds from drones. As far as detection by video is concerned, anything flying in the air is a drone. However, computer algorithms can be utilized to tell flight pattern of birds—a bird will fly at a more random pattern than a drone would. Unfortunately, this notion will fail in cases where birds glide. For example, seagulls will ride wind currents and stay at steady level, which would fool video detection systems.
Recreational drones would be effectively detected at a range of about 350 feet using thermal detection. But this would only work with drones that produce a lot of heat. Unfortunately, most drones do not produce a lot of heat. They are mostly run by electric motors covered in plastic. So, detection by heat signatures would most likely pick up a bird than it would a drone.
Related post: Can Drones Fly at Night?