Controlling UAV Drone Intrusions, by B.I.

I see much interest in the emerging technology of drones. It seems natural for survival groups that wish to band together, and perhaps develop community compounds, to consider drones, which are also known as Unmanned Aerial Vehicles (UAVs), to surveil and protect their environment.

Drones can be either individually controlled by an operator with a “radio control” or pre-programmed to fly a specific pattern and then return to a point of origin. Usually, they send data– telemetry, either digital or video/audio– back to the controller, for whatever purpose the drone has been deployed.

This author is not a drone technician, although he is a long-retired electronic technician. What struck my interest is not so much the exploding technology of drones, which are at the point of becoming a nuisance, but the almost total lack of technology to protect against intrusion by drones from either either the government or private parties. It is a technology that is just starting to emerge, and there are questions as to any effective UAV countermeasures.

The Washington Times reported in an article dated August, 2015, that research on anti-drone technology is at an early stage. To this author’s view, the problem presented can be stated to be in these stages: Detection, Interception, Intervention, and Resolution.


Detection is a large hurdle to overcome, especially with small, private drones, which may be no larger than perhaps a half dollar. Some obvious methods of detection are radar and radio or sound detection. Radar is limited economically to fairly large objects; sound is limited to reasonable close-proximity; radio signal detection has proven productive but is easily foiled by the UAV and its controller using a prearranged sampling of various frequencies.

Much attention was drawn in the Spring of 2015 to a UAV countermeasures system called Anti-UAV Defence System (AUDS). Developed by a trio of British companies, AUDS claims to use a highly accurate radar tracking system with an unsurpassed ground clutter suppression technology for effective near-horizon detection of flying objects. It then employs the very latest electro-optic infrared day and night cameras and state-of-the-art digital video tracking technology to automatically track any UAV intrusion and classify the target. The system then uses a “smart radio frequency inhibitor to selectively disrupt various command and control communication links employed by the UAV”.

On the face of it, this appears to be a working system. It has been tried in the DMZ between the two Koreas. Unhappily, for small local groups, it sells for about £800,000, or about $1.2 million. It is sold in the U.S. by Liteye of Centenniel, Colorado.

Also in the Spring of 2015, Popular Mechanics Magazine highlighted a sound detection system developed by DroneShield, a Washington, D.C.-based startup company. The system uses weather-proof microphones and digital algorithms to discern distinct acoustic propeller patterns, which it must isolate from all other background noises. The company claims it can detect these sounds from as much as 1,000 yards away from the sensor. When an intrusion is detected, the unit sends an alarm over the local Wi-Fi/cellular network as a text message or e-mail. As many detection sensors as desired can be deployed; DroneShield says that can run the costs from about $1,000 to more than $100,000.

The system was deployed at the Boston Marathon in 2015. While DroneShield has not mentioned any specific intervention method, they refer to the possibility of portable net guns.

A Berlin company, Cyborg Unplug, makes a device that plugs into a local electrical receptacle and connects into the local wireless network. When an unauthorized signal touches that network, it shuts down the video, audio, or other information the device is capturing. In “Territory” mode, it monitors an individual’s network; users simply plug in the Cyborg Unplug device and select which devices they want banned from the network. In “All Out” mode, Cyborg Unplug disables any wireless surveillance technologies in the Cyborg Unplug’s range on any network.

The unit does not shut down the drone, only the camera or device that the drone is carrying. The company says that two plug-in units would cover a residence and cost about $112. The device may not yet be legal in the U.S., due to “jamming” regulations.

“Batelle’s DroneDefender™ is a rifle that shoots radio pulses at a drone, disabling it at a distance of 400 meters,” reported in October of 2015. The rifle is designed to confuse the GPS capabilities of the drone and disrupt its remote operations. The intent is to cause the drone’s automated systems to either return it to the point of origin or to land it. Battelle says that the rifle could disable any hostile armament mounted on the drone, such as explosives or chem/bio weapons. The rifle weighs about 10 pounds and can be operated from a fixed mount or as a portable.


Interception can take many forms, as already noted. Law enforcement is beginning to come to grips with this new technological threat. Reuters reports that the New York City Police used a microwave-based system in Times Square on New Years of 2015 to track a commercially-available drone. Their hope was to take control of the drone and return it to its base, thus neutralizing any possible threat and identifying the drone operator. Success was hindered by interference from nearby media broadcasts. The outcome is not clear.

Especially over populated areas, authorities are loathe to disable a drone or crash it, due to possible damage on the ground. They prefer to take control of the UAV and return it to its point of origin, thus identifying the operator. To shoot it down could activate any on-board weaponry. UAVs operated near airports present their own unique set of challenges for authorities to deal with.


Domestic Drone Countermeasures (DDC), manufactured by APlus Mobile, Inc., uses a “mesh network” of detectors to triangulate moving transmitters. Network communications is via Wi-Fi and scans frequencies in the range of 1MHz – 6.8GHz in order to effectively detect all known drone transmitters. Base operations can choose from all detected transmitter signals as to what is acceptable and what should be rejected. Any signal that is not purposely ignored by base operations, the system assumes the rogue transmitter is hostile.

Like many UAV devices and countermeasure devices, the system operates with a Linux operating system. Wireless mesh networks are being increasingly used by local government operations and can be self-adapting to changing conditions. As many detector nodes can be added as needed to cover an expanding area. These expandable networks are attractive for outdoor events, such street fairs, outdoor concerts, and political rallies, where hard wire connections are difficult or impossible.

DDC suggests a countermeasures net over or around an area to capture small UAV’s, even a kevlar net with conductive elements woven into the sensor net. If any of the sensors woven into the net are broken or interrupted, the unit activates an alarm; the impact of a drone would sever a conductive sensor element, and thereby break the circuit.

DDC company president, Amy Ciesielka, told The Huffington Post that the system is not designed to disable the UAV or jam its signals; it is intended to neutralize the ability of an air-borne drone to aquire data, such as sound or video. Ciesielka said that the system was worth as much as a car, perhaps an Audi.

APlus Mobile, Inc., the parent company of DDC, makes and sells defense-level computer hardware systems. According to the company’s website, any buyer of the anti-drone system must sign a non-disclosure agreement and must be an American citizen.


Christopher Samson– podcaster, writer, and producer– wrote on Linked in that the DDC system and some other UAV countermeasures may just be a money-making hoax. He calls them “untested and ineffective”, and points out that they are not comprised of new or cutting-edge technology.

Certainly the military and government agencies can afford advanced technologies, including finite radar systems, laser ‘guns’ and counter-strike UAV’s. The problem of the proper way to deactivate an intrusive drone and/or dispose of it certainly presents many challenges.