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EETE JULAUG 2015

UWAS: playing hide and seek with drones By Julien Happich The Paris Air Show was rich in drone solutions, from warfare mean machines to consumer toys and everything in between for the professional user. Yet, the recurring unauthorized flights that have been reported in the French national press over sensitive sites (embassies, nuclear or other industrial sites) have brought bad publicity to drones in general, making French authorities fear that those flights may be tied to terrorist or other criminal activities. Even if the flying rules put forward by the DGAC (France’s Civil Aviation General Office) and the heavy fines may tame the occasional aerial photography amateur, violating the sky rules is as easy as flying your drone too far and too high over public landmarks or private properties. Hence the necessity to develop counter-measures to detect, track and intercept malevolent drones and their pilots. This is the aim of the global partnership signed during the Paris Air Show by leading radar and security experts, calling for the development of a so-called UWAS System (UAV Watch and Catch System). Partners include JCPX Development, an engineering company producing systems for the protection of sensitive sites, the DSNA Services founded by the French DGAC and the ENAC (the national school of civil aviation), the industrial partner Aveillant for its expertise in radar surveillance, and Skysoft for its know-how handling recordings, data fusion and restitutions. The UWAS System will be designed to address the unauthorised flights of drones over sensitive areas, events and VIP facilities by enabling the detection, monitoring, visualisation and tracking of small drones less than 25kgs. In fact, a prototype system has already been put together, fully operational and compliant with aeronautical system requirements. The first deliverables come in the shape of a portable box of approximately 25x25x25cm in size, supporting an automatic 24/7 radar surveillance system capable of detecting drones as small as 10x10cm in size at a distance up to five nautical miles (approximately 8 kilometres) and up to a height of 1,000m. UWAS also includes a ground-based optical tracking system enabling the tracking and identification of the target drone and a control/command and monitoring interface to be made either portable or integrated in a remote command post. EETimes Europe caught up with Jean-Christophe Drai from JCPX Development who gave us his insight on how the system works and could be used. Although he didn’t want to unveil what components were inside the box, nor if everything had been built off-the-shelf or required some ASICs, Drai emphasized the solution went way beyond the simple detection of drones. “Very early on, our system is capable of extracting several parameters from the echo it receives, including the number of rotors, the spacing between the motors, their speed of rotation, the wingspan. From there, we can search for a match in our database of commercial drones to identify the type of drone that is approaching and its payload characteristics”, said Drai. “Because we acquire data very fast with measurement points only 25ms apart (40Hz), we can track the drone continuously” he added. “In some cases, a simple risk prevention may just be to shelter VIPs inside a building, say in the case of a paparazzi”. “Then our ground optical system is able to infer the 3D coordinates of the drone, this is completed by an integrated frequency analyser that allows us to track the signal source of the radio controlling the drone. So depending on the nature of the drone or the site being monitored, we could either fly a drone there to have footage of the pilots and make them aware that they are being tracked, or directly dispatch security forces to arrest them”, Drai continued. “Of course, we have to think about various interception strategies and most probably the DGAC will have to define new rules of engagement for the interception of drones breaking sky rules, but the beauty of UWAS is that it is fit for any strategy” said Drai. “Based on a first architectural audit, the system could be placed at the corners of an industrial site to protect several quadrants of the sky, or several units could be assembled under a unique dome to cover a site from all directions.” What about taking down a drone before it reaches its target? “As for taking down a drone, it is always a sensitive issue, it really depends over which area the drone is flying and the risks that taking it down could pose to the population or the sites on the ground” admitted Drai. Signal jamming is not an option because it is not directional enough, Drai said. Nevertheless, several options are being explored, including sending an interceptor drone to zap the other drone with an EMI flash, or having the interceptor drone equipped with net launchers or even some sort of containment bag, but here Drai didn’t want to give more details nor become alarmist. “On top of that, legislation will surely have to evolve. One thing that may become compulsory for drone makers is to integrate some form of ID chips or even radio transponders. In most cases, this would make prosecution easier”, concluded Drai, although he admitted highly motivated criminals would easily build their own non-compliant drones. 4 Electronic Engineering Times Europe July-August 2015 www.electronics-eetimes.com


EETE JULAUG 2015
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