The Drone Threat

Unmanned vehicles, referred to as drones in this paper for ease, are unquestionably useful, but the problem is that this is true even for bad guys. The million-dollar question in the billion-dollar unmanned industry is how to stop rogue drones while maintaining complete operational freedom. A non-traditional threat, for example, may not necessitate as many resources as a conventional war does, but its occurrence is more likely and unpredictable. In war, one is prepared to face the threat and losses are considered part of the game, whereas in peace time rogue operators can bring on an embarrassing surprise. An attack on a critical installation, or even an attempt that goes undetected, will leave an unanswered question: was everything possible done to thwart the threat, or were the solutions reached at based on convenient assumptions? Drone threat looms large all the time; therefore, a comprehensive strategy to combat this ever-present threat is a need of the hour.

Leaving aside the war scenario and High Altitude Long Endurance (HALE) and Medium Altitude long Endurance (MALE) class of Unmanned Aerial Systems (UAS) since they are more like an aircraft, concerns for dealing with a rogue or illegal drone are shared by all the security forces. Anti-drone solutions are required by the Defence Forces, Coast Guard, Border Security Force (BSF), National Security Guard (NSG), Bureau of Civil Aviation Security (BCAS) and civil police, to count a few. Whether it is an air force base, an army cantonment, a busy civil airport, or a prestigious international event, a drone can inflict unacceptable damage, not only in physical terms but also in terms of national pride. Since there are many defenders and one threat, their understanding of how to combat this threat should be somewhat common, and a well formulated national strategy can lay down guiding principles.

India has a well-articulated Drone Policy 2021^[1] that is updated on a regular basis, but an anti-drone policy is still being developed. Policy, on the other hand, should not be confused with strategy. While policy essentially defines who can and cannot do something, strategy explains how to do it.

Countering the Drone Threat

Passive radio frequency (RF) detection, high definition Electro Optical/ Infra Red (EO/IR) cameras and acoustics sensors can play an important role in creating a multi-sensory solution, but have their own limitations. Passive RF detection needs multiple sensors at different places to obtain a fix and the problem gets compounded if the target is a moving platform. Demonstrated passive RF detection on ISM (industrial, scientific, and medical) frequencies that operate in common WIFI (2.4 and 5 GHz) or (400 and 900 MHz) bands may not work for a rogue operator who could be operating outside these frequencies or not using a communication link at all like in preprogrammed autonomous drones. Wide band detectors are possible but finding the exact frequency of operation would be time consuming and cumbersome as there could be a whole lot of other devices operating at those frequencies and the detector would then need an Artificial Intelligence/Machine Learning (AI/ML) function to differentiate between a drone and a walkie talkie – too much effort for a simple passive RF detector.

Introduction of 5G has added another dimension where the communication is not dependent on direct link between the drone and the operator. 5G utilises higher radio frequencies to transfer more data over the air for faster speed, reduced congestion and lower latency, and most important Beyond Visual Line of Sight (BVLS). Satcom connectivity, which was earlier available only to military grade drones, is now likely to be available commercially, enabling the drones but compounding the problem for counter drone operations.

EO/IR devices, apart from having limited Field of View under high magnification necessary for identification, are adversely affected by atmospheric obscurities and emissivity. The acoustic signature produced by Low, Slow and Small (LSS) drones will invariably get masked by the normal urban environmental noise, providing very short detection range. Radar is the only sensor which can provide a complete 3D awareness in all-weather at decent ranges, though the band needs to be carefully chosen based on the specific requirements. A well formulated strategy can guide the responders on the selection of appropriate bands.

RF and Global Positioning System (GPS) jamming work well but only against the drones that use these inputs. Preprogrammed autonomous drones will be immune to them. Moreover, it will take time for an operator to realise that RF/GPS jamming is not working, which could lead to their extended operation, causing disruption to own operations. Moreover, most of the commercially off the shelf (COTS) available jammers would cater for ISM bands, as explained above. As a result, RF jammers are only useful against compliant operators, while the problem is with those who do not adhere to these frequencies.

Kinetic kill is another potent option achieved through missiles or Directed Energy Weapons (DEW). Use of missiles against drones is expensive and the drones may not provide enough heat signatures for relatively cost-effective heat seeking missiles defeating the cost advantage. Hand held guns have very limited range and accuracy. DEW harnesses the power of focussed electromagnetic energy to neutralize the threat. HEL (High Energy Laser) and HPM (High Power Microwave) complement each other in combating drones. While HEL can destroy individual drones, HPM can eliminate swarms. Defence Tech giants like Northrop Grumman and Raytheon Technologies have made substantial investments in this field. The Rapid Capabilities and Critical Technologies Office (RCCTO) of the United States Army recently awarded Epirus, a technology company in the USA, a $66 million contract in support of the Indirect Fire Protection Capability-High-Power Microwave Program.^[2] As per a report of Government Accountability Office (GAO), the USA Department of Defence (DoD) allocates a yearly budget of $ 1Billion towards developing directed energy weapons, which indicates that it’s still a work in progress.

In India, as per a report in the Government Economic Times^[3] Centre for High Energy Systems and Sciences (CHESS) a DRDO laboratory in Hyderabad has been experimenting with the DEW technology development that includes DURGA II (Directionally Unrestricted Ray-Gun Array), a 100 KW light weight DEW system. The DRDO produced laser system deployed at the Red Fort on 15 Aug 2022 was claimed to have range of 1.25 KM^[4], which must be under ideal conditions. A caution needs to be exercised while basing the defence systems based on DEW. It must be noted that the DoD USA has been pursuing these technologies for more than a decade placing huge investments at its disposal and yet fears the phenomenon known as “Valley of Death” – a gap between the development and requirement of technology. The MoD and Ministry of Home in India need to evaluate this development realistically.

Drone catchers have also emerged as an option. Ukraine’s Minister of Digital Transformation Mykhailo Fedorov has confirmed that the country has received the first six interceptors ‘Shahed catchers’ from the US. According to the minister, Ukraine purchased the most modern systems that includes radars, jammers, artificial intelligence technologies and a Drone Hunter with net catcher. Many options of net catchers are available in the market but a system must be fully autonomous, capable of day/night operations with advanced AI/ML algorithms.

Need for Counter Drone Strategy

A drone threat can emerge in different scenarios with different stakes at risk and hence, a 'one size fits all' approach to anti-drone solutions may not work. The availability of multiple solutions can sometimes lead to a poor choice. What may be adequate for defending a small site may not be adequate for defending a large complex and may not work at all for a moving platform. For example, a laser gun will need focussed illumination on a spot for a few seconds based on the power output, maybe best suited for a defender manning a post, but may not be suitable at for defending a convoy. What works for a single drone, like a drone catcher, may not work against a swarm, where powerful jammers or HPM would be most effective. Indiscriminate use of jammers may create chaos on a busy airport or a dense urban area. While quick decisions are important in the face of a sudden threat, this aspect cannot be overstated to justify the lack of guidelines, which would increase the likelihood of quick decisions being correct.

Anti-drone strategy essentially has to ride on Drone Policy itself. For example, the drone policy, in Part II, para 4, classifies drones into different. categories^[5]Anti-drone strategy could add type of flying like, hobby, commercial and military/security specifying the duration of flight and maximum speed. Same policy, in Part III para 12, lists mandatory safety features that the government may ask the drone manufacturers to comply with any time; Geo fencing is a part of it. The anti-drone strategy may make it mandatory to geo-fence certain Red Zones for drones’registration. This will ensure that unintentional mistakes don’t cause alarm and no time is wasted in the case of an intentional breach.

Counter Drone Efforts in the Developed Countries

Most developed countries have realised the need for a counter drone or unmanned strategy. The USA established Joint C-UAS Office (JCO) in 2019 with a purpose “to lead, synchronize, and direct C-sUAS (Countering small Unmanned Aircraft System) activities by looking at doctrine, requirements, materiel, training standards, and capabilities to establish joint solutions with a common architecture to address current and future emerging sUAS threats. Through the JCO, the Department will ensure there is consistency of approach, technology, operational constructs, and developmental intent for joint C-sUAS solutions”.^[6] In the UK, National Protective Security authority (NPSA) coordinates with the counter drone unit of the home office and other government agencies to maximise efficiency and minimise confusion in implementing credible anti drone solutions.^[7]

Interoperability between various agencies is important for effective utilisation of resources and efficient solutions. The NATO Communications and Information Agency (NCI Agency) conducted NATO's Counter Unmanned Aircraft Systems (C-UAS) Technical Interoperability Exercise 2022 (TIE22) in Vredepeel, Netherlands, from 13 to 23 September 2022 with over 250 participants.^[8]A similar exercise was carried out by Interpol with over 300 participants from more than 50 countries. ^[9]India has already had an experience with its Herons and Searchers procured by the three services that were not interoperable. A national level strategy will overcome such issues.

Way Forward for India

India must formulate counter drone strategy involving all stake holders. The counter-drone strategy must provide a comprehensive understanding of the evolving risks posed by the malicious and illegal use of drones, as well as take a 'full spectrum' approach to deter, detect, and disrupt drone misuse. It must provide access to counter-drone capabilities as well as effective legislation, training, and guidance to operational responders. It must aid in the development of strong relationships with industry in order to ensure that their products meet the highest standards. Counter drone strategy will act as a deterrent and like a good deterrent, will prevent the undesirable occurrence without even coming into play – the only requirement is its credibility.

References:

^[1]https://egazette.nic.in/WriteReadData/2021/229221.pdf
^[2]https://www.epirusinc.com/news-item/us-army-awards-epirus-661m-contract-for-leonidas-directed-energy-system
^[3]https://government.economictimes.indiatimes.com/news/technology/drdos-centre-for-high-energy-laser-systems-on-a-mission-to-modernise-defence-technology-of-the-nation/94132360
^[4]https://indianexpress.com/article/cities/delhi/delhi-i-day-security-red-fort-counter-drone-system-8090272/
^[5]Nano  250 grams; Micro > 250 grams to  2 kilograms; Small > 2 kilograms to  25 kilograms; Medium > 25 kilograms to  150 kilograms; and Large > 150 kilograms.
^[6]https://media.defense.gov/2021/Jan/07/2002561080/-1/-1/1/DEPARTMENT-OF-DEFENSE-COUNTER-SMALL-UNMANNED-AIRCRAFT-SYSTEMS-STRATEGY.PDF
^[7]https://www.npsa.gov.uk/countering-threats-unmanned-aerial-systems-uas
^[8]https://www.ncia.nato.int/about-us/newsroom/nci-agency-holds-natos-livetesting-counterdrone-exercise.html
^[9]https://www.interpol.int/en/News-and-Events/News/2022/INTERPOL-convenes-global-summit-on-the-use-of-drones
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