Effective and affordable detection of small UAVs using millimetre wave coherent Doppler radar.

Small unmanned aerial vehicles (SUAVs), or drones, have become incredibly popular due to advances in affordable technology which allow them to be very easily controlled, and fully autonomous GPS-guided SUAVs are now publicly available. However, the nefarious use of SAUVs is also increasing and they are now regarded as a potential threat to public privacy, safety and security. There have been many news reports of unwanted SUAV incursions in recent years including Angela Merkel being buzzed at an event in 2013, several mystery drones being sighted over Paris in early 2015, and two cases of SUAVs landing in the White House grounds in 2015.

What if a SUAV-borne camera is being used for reconnaissance at a government building prior to a terrorist attack? What if a SUAV is flown into the path of an aircraft taking off at an airport? What if a larger SUAV equipped with a weapon or explosives is used to attack a large crowd or a nuclear power station? Sadly, these are all credible threats which we cannot ignore and this demands that we have the capability to detect intruding SUAVs and ultimately intervene to neutralise the threat.

The successful detection of the intrusion into controlled spaces by small UAVs depends on being able to detect them reliably at sufficient range, i.e. in sufficient time, to be able to take appropriate evasive action whilst discriminating them from other harmless objects. Any sensor has to achieve this in locations containing complex structures and confusing background signals.

Radar is one of the best techniques to achieve SUAV detection because it is capable of measuring the characteristic Doppler signatures of the rapidly rotating propellers and thus has the potential to distinguish SUAVs from other moving objects such as birds. However, conventional microwave radar struggles to detect the reflections from SUAVs due to their small size and low metal content.

Our previous STFC-funded research has shown that shorter wavelength, millimetre wave radars are particularly well-suited to detecting low reflectivity, slowly moving targets. In that work we developed a radar to measure the Doppler signatures of tiny cloud particles moving high up in the atmosphere. In this project we propose to apply those same techniques to develop a low power, compact, millimetre wave radar demonstrator which will be capable of detecting SUAVs with high probability, and low false alarms, over a wide search area.

We believe there are significant market opportunities for compact, low cost millimetre wave radars which may be deployed rapidly and as part of an ad hoc network that can be easily reconfigured to meet the demands of a wide range of site installations. We anticipate that variants of the radar will be suitable for both fixed, permanent installations (e.g. Centres of National Infrastructure (CNI), power stations, airports, government buildings, and data centres) and flexible, temporary deployments (e.g. VIP appearances, music festivals, motor sport events, sports arenas, parades / demonstrations). Our Project Partner, BAE Systems Applied Intelligence Labs, is very well placed to capitalise on these markets given their track record and experience.

Beyond the direct economic opportunities of supplying equipment to this potentially large market, there are significant indirect economic benefits to being able to prevent SUAV intrusion. Preventing delays, evacuations or ultimately crashes at airports caused by SUAV intrusion will protect the enormous contribution these transport hubs make to the UK economy. Furthermore, preventing the unauthorised recording/filming of new movies and major sporting events from SUAV-borne cameras will protect valuable intellectual property. Of course, the threat from SUAVs is not limited to the UK: if a reliable system is developed from this research, it could be exported to foreign nations that share the same concerns, bringing further wealth to the UK economy.

Social: The proliferation of small UAVs (SUAVs) has been accelerated by advances in affordable technology which allows even the most inexperienced of pilots to have good control of the craft, and fully autonomous GPS-guided SUAVs are becoming ever more affordable. Furthermore, the increasing payload capacity of SUAVs makes them potentially ever more dangerous. The negative social impact of SUAVs is already being seen, with well-publicised incidents of snooping and invasion of controlled spaces (e.g. Angela Merkel, Sept. 2013; Paris, Feb/March 2015; White House, Jan & May 2015).

The development of an affordable and reliable method of detecting the intrusion of SUAVs into controlled environments will bring enormous social benefits through an increase in the privacy, safety and security of the citizen by:
(i) Preserving the dignity and privacy of public figures (e.g. Royal Family, politicians, VIPs) and members of the public by preventing unwanted photography/filming and harassment.
(ii) Enhancing safety at crowded places (e.g. festivals, parades, sports events).
(iii) Enhancing the security of sites of critical national infrastructure (CNI) (e.g. airports, border crossings, power stations).

Economic: The nefarious use of SUAVs can also have a negative economic impact. One of the most compelling cases for economic benefit is the prevention of a SUAV overflying or landing on a major airport runway, such as Heathrow. If COTS millimetre wave radar systems can be exploited to provide a SUAV warning system at a modest price-point, integrated with existing perimeter security systems, they could prevent the huge costs incurred by delays in flights and possible airport evacuations. Furthermore, this would help maintain the reputation of the UK's airports as being amongst the safest and most efficient transport hubs, thereby protecting the enormous contribution they make to the UK economy.

The production of TV series and feature films is a multi-£billion industry so studios and production companies make every effort to protect their intellectual property and keep information about new productions secret until the official release. Film set overflights by SUAVs equipped with high definition cameras not only compromises this IP but can incur expensive delays in shooting and potentially places the cast and crew in danger. Similarly, the broadcasting rights to major outdoor sporting and music events are very lucrative and vigorously protected so unauthorised recording/filming, either directly from SUAVs or by cameras delivered to inaccessible locations (e.g. on the stadium roof) by SUAV, could be prevented by deploying a counter-SUAV system.

We believe the most relevant initial applications scenarios are (i) permanent security installations for CNI sites such as nuclear power stations, airports, oil refineries and major government buildings and (ii) temporary security installations for public events such as music festivals, sporting events, VIP appearances, etc. delivered through event security companies. The potential market for the above two scenarios is obviously massive, with most scenarios of any size requiring the use of multiple sensors providing either an upward pointing "radar fence" around the perimeter, or nearly complete hemispherical coverage around a site. Our Project Partner is very well placed to capitalise on these markets given their track record and experience.

A successful commercial solution will be achievable by leveraging low-cost millimetre wave chipsets from the automotive and communications markets. There will be substantial economic rewards available to the system manufacturer, supply chain companies and security providers. Of course, the threat from SUAVs is not limited to the UK: if a reliable system is developed from this research, it could be exported to foreign nations that share the same concerns, bringing further wealth to the UK economy.