5 technologies applied to drones & their legal implications in 5 days. Day 1: Counter-drone technology.

Published: 16 September 2019


Counter-drone technology makes the news nearly as much as drones themselves. Let’s have a quick look at how some of this technology works and some of the legal implications of its use.

Counter-drone technology typically includes drone detection and drone disabling technology.

Drone detection

Drone detection technology includes:

  • Radar, which sends out pulses of radio waves which are reflected off an object back to the source. Radars are typically designed to detect large, fast moving objects, rather than small, slow moving drones at low altitude and which could be confused with a bird.
  • Acoustic sensors take in sounds, which are then compared to a database of existing sounds to identify the sound of a drone. The accuracy depends on the database it searches to identify whether the sound is a drone.
  • Radio Frequency detection requires specialised equipment to monitor the radio frequency spectrum to detect the command and control link between the pilot and the drone.
  • Electro-optical detection converts light, or a change in light, into an electronic signal. It scans the sky, looking for variations in pixels that could represent the presence of a drone. This often also refers back to a database of images.
  • Infrared can detect drones based on its heat signature.
  • Combo-deal: many drone detection products incorporate a number of these for a more robust detection system.

Drone disabling

Drone disabling technology can be broken down into kinetic and non-kinetic options.

  • Kinetic options involve physically damaging or interfering with a drone. This includes falcons trained to catch drones, anti-drone drones that take out the ‘rogue drone’, to net guns, firearms, and my personal favourite, a 65-cent roll of toilet paper I’ve seen take down a drone more efficiently than the fanciest technology.
  • Non-kinetic disabling technology interferes with a drone without direct physical contact. This is usually by intercepting or interfering with the communications signals that drones rely on for guidance and control.
  • 2 types of non-kinetic counter-drone technologies are jammers and protocol manipulation systems.

[1] Jammers are devices that disrupt the communication between the pilots ground control system and the drone. Examples include radio frequency jammers and GPS jammers. As a result of being jammed, the drone may fall from the sky or else enter a pre-determined fail-safe mode such as landing immediately, hovering or engaging a ‘return-to-home’ function.  Jammers are effective but not particularly targeted in that they disrupt everything in their path operating in the relevant radio frequencies or GPS signal. There is a risk of collateral damage.

[2] Protocol manipulation is another type of non-kinetic disabling technology. This is a communications interception, which is essentially hacking. The hacker disrupts the signal between the drone and its pilot, then clones that signal to impersonate the drone’s controller, and then takes over control of the drone.

Legal implications

  • Most of this counter-drone technology is, on the face of it, illegal. At present, it’s largely reserved for police and military operations.
  • 2 high-level observations.

[1] Under the Civil Aviation Act 1988 (Cth) the definition of an “aircraft” is broad enough to encompass a drone. Section 24 of the Civil Aviation Act prohibits a person from tampering with an aircraft if tampering with it may endanger the safety of the aircraft or any person or property. This is punishable by imprisonment for up to 2 years.

[2] The other aspect under which some counter-drone technology may be captured is under the anti-hacking legislation. This may be caught under provisions of the Criminal Code Act 1995 (Cth) for computer offences, including: 477.3: unauthorised impairment of electronic communication.

The take-away is that without specific approval or exemptions, the use of counter-drone technology by private citizens is very risky and likely to be illegal.

Fly Free!

The Drone Lawyer

16 September 2019