Flying drones – a real threat

Ways of defending against drones


Drones represent a serious threat. The relevance of this threat varies, of course, from organisation to organisation. Correctional facilities were the first to take the threat of drones seriously. Smuggling in drugs and telephones is easy to do using drones and has a manageable risk level.

Like a dark shadow, the scenario of a terrorist attack conducted with the help of a drone is taken particularly seriously in the considerations of event security. Most security concepts for large events do not adequately address this threat (e.g. Drone gets to within a few meters or Angela Merkel).

When you consider that many civilian drones can now carry a weight of 100kg, their terrible potential becomes quite clear: they are able to transport and control significant amounts of explosives or fully automated weapons.

There have been incidents with civilian drones in recent years, e.g. in football, luckily none of which had terrorist motives. So it is reassuring to know that France is taking measures to prevent drones for the upcoming European Championships.

While France protects its population in an exemplary approach to handling drones, others still seem to have their heads in the sand. This may be due to the fact that there hasn’t yet been an incident resulting in personal injury – which is often the cause of negligent restraint when it comes to security issues. Or it may be that uncertainty prevails as to whether and by which means we can combat the threat of drones. If this is the case, I would like to help by listing the currently known (and legally permissible!) methods of drone defence.

Detecting drones

The necessity for the unambiguous detection of drones must be mentioned at this point. Because ultimately, the very best defensive measures do not help if the drone is not identified as such on its approach. The following approaches are currently available:

  • Organisational (Security Awareness): Employees know about the threat potential of drones, raise the alarm and trigger a regulated process.
  • Video analysis (conventional): Existing video monitoring systems are supplemented with cameras aimed toward the sky. The software for video analysis is parameterised accordingly and triggers an alarm when it detects a flying object of a defined size.
  • Multi-sensor detection: Every drone has clear distinguishing features: Shape, size, pattern of movement – but also their flight noise and WLAN signals. These features are detected using various sensors and evaluated on a software basis. This minimises the number of false alarms.

Defending against drones

  • Capture drone: Captures a hostile drone in a net. Prerequisite: good (!) pilot, available 24/7.
  • Firearms, electromagnetic pulse (EMP), laser: Destroys the drone. Prerequisite: official authorisation, authorised person.
  • Trained birds of prey (it’s no joke!): at least the Dutch authorities are backing this concept…
  • Net cannons: A net is fired toward the drone from the ground or building. Problem: limited range – so not suitable for counterintelligence.
  • Jammer/spoofer: interrupts the radio or GPS connection – the drone automatically flies back to the starting point or crashes.

The above-mentioned measures work in practice! So there is no longer any reason to have citizens, event visitors or employees of critical infrastructures exposed to the potential threat of drones. France serves as a good example in this regard.