The Evolution of Small Drones

In recent years, military personnel have become increasingly familiar with the use of drones for anything from practice targets to air strikes. Military drones show huge promise and will certainly play an important role in the decades to come. With the de-encryption of the GPS system in 1999, there was suddenly an opening for civilian manufacturers to build self-flying systems. From this event, among others, the civilian drone market was created. By 2005, professional systems such as the MD4-200 from Microdrones GmbH, with its ability to provide an aerial photography and mapping platform, grew to be a mainstay of the market. Since then, hundreds of manufacturers have built their models and sold some tens of thousands of systems in the high-end market.

Payload and Range

Putting us in the post-professional civilian drone era, DJI disrupted the market with the launch of the rotary-wing DJI Phantom in early 2013. DJI places the cap­abilities of larger systems into a hobby package, which can be purchased for less than 1,000 EUR. Its oper­ation can be mastered by nearly everyone.

The DJI Phantom’s payload is listed at 200 grams, but unofficial tests confirm a capability of up to 1,000 grams. On 6 April 2014, a drone operator flew a standard DJI Phantom mounted with a camera for 16.4 kilometres while following it by car. Alternatively, the flight could have been conducted in a pre-programmed mode. Added payload weight would, of course, have altered this result. However, in general, it can be assumed that modern civilian drones can deliver 1 kilogram at a range of 5 kilometres through programmed flight.

Common professional drones such as the Aerialtronics Altura Zenith can carry up to 4 kilograms for as far as 15 kilometres. The Dronera X12U has a payload of 100 kg and battery endurance for 35 flight minutes. The technical specifications of the DJI Phantom features look minor in comparison; however, one can imagine that its small payload combined with its long range offers possibilities for many useful applications. Numerous manufacturers are offering small drones with similar features as the DJI Phantom to the civilian market, which presents a huge potential for commercial use.

Potential Malicious Applications

The increased capabilities of commercially available drones provide multiple areas of concern for security professionals:

1. Imaging. By autonomously flying over restricted areas and collecting thousands of low altitude, high-resolution images, an ultra-high resolution aerial picture could be created. These images, including de­tailed topographical information, allow an opponent to covertly create maps of areas that are off-limits to them. The operator could see details down to 1 cm2 and calculate the topology with astounding precision. Furthermore, in order to enhance intelligence collection, sensors such as thermal cameras or multispectral payloads might be used to create maps of heat sources, tap wireless networks or provide other types of sensor information. In short, drone-assisted mapping gives forces without satellite capacity the capability to collect high end imagery Intelligence.

2. Observation. Obviously, small drones can transmit or stream their video signal back to their operator. Such awareness would allow an opponent to plan entry into a compound and stay hidden from protective forces. Previously, strong video transmitters were required for this purpose, but technology has evolved and transmitters with low signal strength and even encryption are available now. Finally, modern mobile phone networks such as 3G/4G allow for direct streaming of High-Definition (HD) video with minimum latency to anywhere in the world with high-end encryption.

3. Smuggling. Smugglers on all continents have already discovered the possibilities that commercial drones provide. Drones allow for trafficking contraband such as drugs, weapons, information, and mobile phones into compounds such as prisons, but also across borders – all without the risk of capture. Additionally, drones might be used to smuggle information and even technology out of secured areas.

4. Hacking. Small routers specifically manufactured to scan for vulnerabilities in a wireless network are ­already commercially available. Drones may be equipped with such devices, remotely uncover these vulnerabilities in an organization’s network infrastructure and allow an opponent to gain access to data not accredited to them.

5. Tapping. So called IMSI-catchers, which can exploit the International Mobile Subscriber Identity (IMSI) stored on the mobile phones’ card as well as false ­cellular phone base stations are available from online stores. Drones would allow an opponent to covertly position such devices on rooftops and other locations to create optimum coverage. The devices would allow for intercepting communications (voice and data) conducted on the cell phone networks in range. In the past, fenced and guarded premises created enough stand-off to make such techniques useless. However, small drones could easily place such devices under the cover of darkness, allowing intelligence ­collection for as long as batteries will allow.

From Kids Toys to Terrorist Weapons

Commercial-Off-The-Shelf (COTS) drone systems with the possible applications stated above provide the operator with an infinite amount of nefarious possibilities. It would be naïve to believe that criminals or terrorists will not make use of these opportunities. As far as criminals are concerned, it can be assumed to be standard that they grab whatever technology is available and use it for malicious intent.

Terrorist use of drones has been widely reported since 2014. Drones were not only employed for intelligence collection. Current reports mention drones fitted with explosives, guns, fluid and powder dispersion devices for chemicals and more. In some areas, DJI Phantoms have been used for counter-sniper work, suicide bomber support and even direct attacks with explosives. Some news stories show militants attaching hand grenades and IED’s to drones for pinpoint aerial delivery. Remembering the DJI Phantom payload of potentially 1,000 grams, terrorists could, for example, drop an equivalent of at least two M67 fragmentation grenades, which have a 5 m fatality range, via a pre-programmed autonomous drone flight with an accuracy of 1 m radius around the target.

Installations such as embassies, oil refineries, prisons, government offices, military bases and communication installations are terrorist targets of interest. In July 2015, both British and American intelligence services reported evidence that terrorist organizations are planning to use drones, or even swarms of drones, to carry out attacks against heavily populated installations such as football matches or festivals.

Given the enormous attention that improvised drone weaponization receives on the internet and the sheer number of systems available, it is highly probable that commercial drones will be fitted and used for attacks within the near future, both within and well outside of recognized warzones.

Improving Security without Expenditures

The first step to solving a problem is admitting its existence. Risk exposure to low, slow and small drones should be a dedicated part in the risk analysis for any building, compound, border or unit. By introducing traditional thinking, one can plan for a number of precautions connected to drones, some of which are: guards should be on the lookout and have a specific alarm procedure; sensitive instal­lations could be covered when not in use; and, VIP visits should generate increased security with regard to drones.

Due to a lack of statistics, probability remains an unknown factor and is not a suitable parameter for establishing a complete risk analysis. One should instead weigh the costs of investment in drone security in relation to the value of the protected asset. What would the loss be should drones compromise the integrity of a base, compound or border after all defensive measures have been attempted?

Available Technologies

There is a growing business sector dealing with establishing drone-secure airspaces. As aviation authorities struggle to keep up with the advances of drone manu­facturers and instead focus on creating regulations for legal drone businesses, control of the large number of drones for recreational use remains an open question. This leaves the responsibility for close proximity air space to the respective landowner.

There are two basic components of drone defence: Detection and Suppression.

Detection devices allow the operator to become aware of a current threat in the airspace, whereas suppression technology enables the operator to counter that threat.

There are currently numerous technologies, such as laser scanning, radar, acoustic, video, radio signal scanning, that can provide drone detection. Each of these technologies carries advantages and disadvantages.

Drone suppression technology is in the early developmental state. Counter-drones, lasers, GPS jamming and spoofing, as well as microwave cannons are being tested with increasing success. All these systems have in common that they may cause a flying object to lose control and crash into the ground. The kinetic energy from such a crash is likely to injure or even kill a person on the ground, opening up a large liability issue for the responsible user. One industry player has introduced the ‘Proportional Drone Response’ concept to the discussion. This concept requires organizations to assess the cost benefit of shooting down drones versus ­allowing them to continue. For safety reasons, it is ­argued that landowners should, in most cases, forego aggressive suppression until it is absolutely mandated for security.

Sound as Detection Parameter

For low-altitude, short range drones, research conducted has concluded that acoustic detection is quickly deployable with a low false positive rate. Furthermore, acoustic sensing is inherently safe, as neither radiation nor signals are emitted.

Any flying system produces specific sound patterns, and, as it turns out, that sound pattern is difficult to conceal. The sound patterns of drones are highly recognizable and are completely different from any other flying objects. To date, the problem has been that regular microphones would not provide sufficient range to be successful as triggers for effective counter­measures (typically, 100 – 150 metres of detection range). However, technological advances and multi-microphone arrays that will extend detection range to over 700 metres are being tested commercially.

Conclusions

The ‘Personal Drone’ has emerged from the hobby builder’s basement to a multi-billion dollar industry over the course of 3 years. In these years, technology has advanced from ‘barely airworthy’ to ‘advanced auto­nomous operations and payload delivery’. With thousands of engineers working on hardware, software, user interfaces and innovations, there will be a sharp increase in available capabilities and systems. These will be ever more powerful, cheaper and easier to use.

Expected developments in the coming years include:

• drones that can stay aloft indefinitely using solar power;
• inexpensive thermal cameras that allow for night-time operations;
• drones that can transport a person;
• homemade weaponized drones;
• intelligent understanding of surroundings, allowing drones a higher degree of autonomy;
• lower prices for basic functions, potentially providing a dispensable drone for single use.

The impending arrival of any of these capabilities will bring amazing opportunities to consumers and hobbyists. However, it also means that the isolated security breaches using commercial drones seen to date are mere precursors to the security challenges to come. As these capabilities become more readily available, drone-related security concerns will continue to grow. It is highly recommended that security analysts pay close attention to the commercial drone industry and that national assemblies and aviation authorities develop le­gislation governing the use of personal drone aircraft.