The two largest airports in the United Kingdom will install military-grade anti-drone systems to fend off rogue drones.

The administrations of the Heathrow and Gatwick airports, which are situated close to London, announced they will spend several million pounds to avoid any future disruptions to their operations caused by unidentified Unmanned Aerial Vehicles (UAVs). Heathrow is the busiest airport in Europe.

Gatwick Airport has already installed a preliminary anti-drone system. Heathrow isn’t far behind and its administration is working closely with the British military and law enforcement agencies to determine the best and most effective equipment to install.

“While I can’t go into detail about exactly what we have, I can confirm this was an investment of several million pounds to ensure we are at an equivalent level to that provided by the Armed Forces,” said a spokesperson for Gatwick.

Between December 19-21, Gatwick was forced to halt its operations for three days over multiple sightings of drones overflying its tarmacs and runways. The event came during the extremely busy holiday season, which compounded the difficulty of the situation. All in all, more than 1,000 flights were cancelled, affecting close to 150,000 passengers. In order for the airport to be declared operational and for flights to resume, the deployment of the British military was required. Although unverified by the British Ministry of Defence (MoD), the anti-drone equipment that was deployed appears to be the Drone Dome System, an Israeli-developed system that is able to detect and jam the communications link between a drone and its operator. With four radars attached, the system is capable of providing 360-degree security and has a range of several miles.

The identity of the drone pilots is still to be determined by the British law enforcement agencies that are leading the investigation and the British military has withdrawn its systems. A spokesperson from the MoD said that “the military capability has now been withdrawn from Gatwick [but] the Armed Forces stand ever-ready to assist should a request for support be received.”

Some drones are small, others are quite large, but all of them are hard to target and shoot down. Commercial drones are minuscule compared to their military counterparts and the challenge is that much more significant. Conventional wisdom would dictate firing shotgun-style volleys in the air to try and shoot down the drone. That approach, however, would not be as effective as it might sound given the fact drones can operate outside the effective range of such weapons. Consequently, anti-drone weapons tend to target the connection between the drone and its operator in an attempt to disable it.