// Blighter A800 3D drone detection radar. Image: Blighter Surveillance Systems

In December 2018, operations at Gatwick airport in the UK were brought to a screeching halt due to reports of a drone sighting. Following protocols, all inbound and outbound flights were stopped.

In September 2019, the threat of long-range suicide drones became apparent during a long-range drone and cruise missile attack on facilities operated by state-owned oil company Saudi Aramco.

In the same year, Greenpeace used a drone to drop a smoke bomb onto the roof of a nuclear material storage building in France’s La Hague.

If environmental activists can drop a smoke bomb on the roof of a building containing nuclear material, it is easy to see how a malicious actor could use a similar method to drop an improvised explosive device instead.

As drones become more widely available and easy to operate, a number of new potential threats to critical infrastructure are emerging. This will require new protection and defence measures for vulnerable infrastructure, such as power installations, airports, and stores of dangerous materials.

In a report published in May this year, US think tank the Atlantic Council wrote: “Think about a violent drone attack on a major international airport, an airport like Riyadh, Cairo, or Frankfurt. What could such an attack look like?

“Maybe it would be a battery-powered, remote-control airplane with a plunger mechanism in its nose, designed to blow up several pounds of explosives when it crashed into a target on the ground like a taxiing commercial airplane. Or it could be a multirotor drone, made of hardened plastic, built for the consumer market but modified, so it can carry a bomb to drop onto a crowd of people waiting for a shuttle bus.

“Either of these unmanned aerial systems (UAS) would be hard to observe visually or detect with radar, let alone defeat before they hit their targets.”

Both hypothetical scenarios, although widely different in scope, demonstrate a clear need for counter-uncrewed aerial system (C-UAS) systems, especially as we look towards a future where drones will be much more widespread and sophisticated; delivering groceries and parcels, and even transporting people in the form of aerial taxis.

“The sky is going to become crowded with drones all going about perfectly legitimate business. The problem is identifying the rogue drone in the midst of a collection of other drones.”

One company working in the C-UAS space is Blighter Surveillance Systems, a British designer and manufacturer of electronic-scanning radars and surveillance systems. Blighter recently launched its A800 3D drone detection radar aimed at tackling drone threats.

The company’s CEO Angus Hone tells us that ‘cheap and easily available hobby drones’ had played a key factor in the increasing interest in C-UAS technology from an infrastructure perspective. Although this threat is still in its infancy, it will grow as the commercialisation of drones gathers pace, says Blighter CTO Mark Radford.

“We will see the proliferation of drones for commercial applications, home deliveries, medical deliveries, air taxis,” Radford explains. “And so, the sky is going to become crowded with drones all going about perfectly legitimate business. The problem is identifying the rogue drone in the midst of a collection of other drones.”

In the past, securing a critical national infrastructure site was relatively straightforward: dot the perimeter with cameras feeding into a control room where human operators can see what is happening in real time; combine this with ground-scanning radar and patrols and as long as you are watching the perimeter the site is protected.

Drones, however, have turned a two-dimensional (2D) security landscape into a three-dimensional (3D) one, with the need to look into every angle of the sky. The Saudi Aramco incident highlighted this shift: although these sites were protected by traditional military-grade air defence systems, such systems are tailored to high-flying threats, but a small drone can fly at low altitude and remain undetected.

Blighter’s A800 3D drone detection radar is designed to look at both aspects, Hone says, but its main function is to detect and locate commercial UAS, such as the quadcopter systems commonly flown by hobbyists. The company says its system is optimised for low-slow-small drones, not dissimilar from the drone used in the Greenpeace incident.

Hone adds that the system could also help to fill in potential gaps in an air defence system, such as those that missed the drones used in the Saudi Aramco attack. Describing a possible setup to secure a critical national infrastructure site, Hone says the A800 could be coupled with traditional long-range radar to get an image of the sub-20km environment. This, he adds, could be paired with the company’s B400 ground-scanning radar to provide a 3D view of threats to an infrastructure site.

In many ways, threats to infrastructure are evolving to become as serious as threats to military installations. In Syria, Russian positions have come under attack from drones on numerous occasions, demonstrating the growing nature of these threats, but also showing that they can be stopped with the right equipment.

“The challenges faced by the military over many years are that the capabilities of the threats are growing all the time,” Radford explains. “And so now, whether it's an airport, whether it's an oil site, they have only been worried about that 2D perimeter. Now, it's become a 3D perimeter, it's become a hemisphere. And actually, it has extended out and has been especially highlighted by the Saudi Aramco issue where it was a long-range drone.”

“The drone threat may require a different level of human capability to manage multi-sensor systems.”

On this front, Radford says, the fusion of sensors and data, which has become a priority for armed forces, is also key for protecting critical infrastructure against the emerging threat of drones.

While technology needs to keep pace with this evolving 3D threat environment, it is important for support contractors and security providers to also keep pace, Hone adds.

“Go back a few years and a perfectly effective way of looking after airports was the heavy use of cameras and having people study a large number of screens for short bursts of a couple of hours at a time,” he explains. “The drone threat may require a different level of human capability to manage these multi-sensor systems.”

Funding can be an issue in building better defences for critical infrastructure systems such as airports and nuclear power plants, as operators are often reluctant to invest in security, which has no revenue generation attached to it, Radford says.

“There is always great caution in investing in new technology,” he adds. “And here comes this brand-new, expensive, currently military-grade, complex technology. As the budget holder, do you really want to invest in millions of pounds’ worth of equipment today, in the fear that everything is going to be so different in two or three years' time?

“As the threat evolves and the airport changes its operations, the radar sensor can also be adapted and upgraded with new hardware and software.”

“One of the key things is going to be a so-called ‘evergreening’ of technology, so that whatever hardware platform is purchased for radar detection, it must be upgradeable, extendable, and adaptable. As the threat evolves [and] as the airport changes its operations, the radar sensor can also be adapted and upgraded with new hardware [and], most certainly, new software.”

Without technology that can be continually upgraded to meet evolving threats, Radford says, “we're going to see airports littered with old obsolete equipment every few years, and that doesn't seem like the right thing to do.”

Explaining how this challenge can be met, Radford compares Blighter’s hardware roadmap to Lego blocks in its scalable and upgradable nature, both on the hardware and software. This, he says, is important to ‘steer’ products to where the market goes and keep pace with a still-evolving threat.