Working to fill the gaps in drone defence

Unmanned aerial vehicles (UAVs) are rewriting military doctrines at a pace that few people could have imagined a decade ago. In the conflict in Ukraine, drones are being used in their millions, both in intelligence, surveillance and reconnaissance (ISR) roles and to actively engage and destroy the enemy. So important are first-person-view (FPV) drones to Ukraine’s war effort that the nation has reportedly increased its production capacity from two million to five million units a year.

Global armed forces are sitting up and paying close attention to the trend. Almost all are now enhancing their abilities to produce unmanned aircraft systems (UAS), while also searching hard for technologies to destroy enemy drones. Machine guns, man-portable anti-aircraft missiles, jammers and FPV kamikaze drones can all play a role. But as drone swarms become bigger and more complex, more solutions are needed to keep enemy UAVs at bay. This need has recently inspired Saab engineers to explore potential new counter-UAS (C-UAS) capabilities. Given the high numbers of drones in action, to be effective new solutions must be able to neutralise multiple drones in a cost-effective way and without placing undue stress on supply lines or manufacturing capabilities. At the same time, because of the speed at which drone attacks can occur, they must be agile, intuitive and simple to use. So, where exactly do the gaps lie in existing drone defences lie? And exactly what are some of the options being considered to plug them?

A potential gap in layered air defence

Currently, well-organised armed forces use a layered approach to air defence, whether defending groups of deployed troops or valuable assets or pieces of infrastructure. Different types of air defences are used to offer protection at different ranges, with these deterrents overlapping to create full coverage. MSHORAD systems might be used to take down threats that are approaching at distances up to a few kilometres away. Saab’s RBS 70 NG man-portable defence system, for example, is capable of destroying targets at a distance of up to nine kilometres. Close-up defences against drone threats can include machine guns and also kamikaze defensive drones, piloted remotely by troops on the ground. Jamming technology can also play a role by interrupting the signal between remote enemy pilots and FPV drones, although the increased use of fully autonomous and fibre-optic-wired drones is removing this advantage.

These solutions together provide great coverage, particularly when used in combination with radar and command and control solutions. However, the growing size of drone swarms is opening up a potential gap in middle distance defences, between close and short range. At a distance of two, three or four kilometres, machine guns are not effective, and it can be hard to get enough FPV kamikaze drones in the air in time to ward off an attack. Enemy drone pilots are often highly trained and expert at defensive manoeuvres, making it extremely hard to neutralise them with conventional weapons. While MSHORAD missiles are effective, their use is not always cost effective. Spending multiple tens of thousands of dollars at a time to take down individual drones that the enemy has commissioned for a few hundred dollars also has the potential to strain supply chains.

Potential solution pathways

Two solutions with the potential to close this gap in an economical and agile manner would be a new type of anti-drone missile and a directed energy weapon. A missile with the same kind of small-drone-killing power as an MSHORAD missile but that is more economical to produce and easier to distribute, could solve many of the challenges. It could potentially be produced rapidly and in numbers large enough to match the millions of drones now in production. However, no suitable design is currently in production.

Directed energy weapons, meanwhile, work by focusing large amounts of energy – such as light or microwaves – on incoming flying objects, causing their destruction. They have been shown to be deadly at great distances. However, a drawback of this option is that it may be some years before directed energy weapons are at a stage where they are ready for mass production. Such weapons also require clear conditions with a direct line of sight for effective use. Even then, they require a precise target fix for several seconds, something that may be impractical when targeting small drones. While no clear option has yet emerged, one thing is clear. With the drone threat growing each day an effective solution is badly needed. And Saab’s engineers are working hard to find it.