Counter Unmanned Aerial Systems (Part 1)

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Rapid Developments Changing C-UAS Scenario

That the world is riding into a ‘Geo-political flux’ is hardly an intelligent statement to be making these days. Power-play manoeuvres are being initiated at multilateral levels – between nation states and across domains; from military to economic, diplomatic, space and cyber amongst others, to either establish supremacy or have the target nation accede with threat of punitive action. Moves to leverage and posture own national assets to safeguard interests either by forging strategic alliances or through regional constructs are the order of the day. Technology is playing greater role in tipping the balance than was earlier envisaged. With this great power competition has emerged the rise of both high and low-end threats that call for a whole of the nation approach to deal with.

Unmanned Aerial Systems (UAS) are nobody’s exclusive preserve. Today, Gen-Z, through the sheer power of their imagination and result-oriented research has galvanized the concept of flying. Technology has further acerbated the utility and with a few alterations to the aerodynamic and software parameters can mutate the airframe to a lethal military grade weapon. By description, UAS includes both Drones and UAVs and the operators controlling them. Just a couple of months back, the Indian Army exhibited the offensive capability of a Swarm of 75 Autonomous Drones with distributed intelligence and Edge computing, destroying a variety of simulated targets including kamikaze attack capabilities during the Army Day parade in New Delhi in January 2021. The capability also exhibited enhancing and reducing the size of the swarms as per operational requirements.

India, due to its geographic location has been touted as a land of opportunities, threats and paradoxes. The Indian vision is intrinsically linked to its regional aspirations and safeguarding its own national security interests. The implications are instructive and include maintenance of territorial integrity both from external and internal threats, security of the vital Sea Lines of Communication (SLOC) and the Exclusive Economic Zone (EEZ). It’s focus and importance was highlighted, on 8 April, in some ways when USS John Paul of the US Seventh Fleet forayed 130 nautical miles west of the Lakshadweep Islands, inside India’s EEZ, without requesting India’s prior consent, “consistent with international law” amidst much consternation from the Indian Security establishment.

Former US Secretary of Defence, Mark Esper, in a statement at the Air Space and Cyber conference, on 18 Sptember 2019, said, “the conveniences of today’s battlefield will not be the realities of the future.” The underlying message that lay there in pointed, amongst others, to the ever-evolving threats from UAS. Just when the world was awe-struck by the maturation of the UAS, another voyage beyond the final frontiers was being undertaken in the realms of counter-UAS.

Developmental Helix

Development of any ‘Counter-Technology’ goes through an iterative spectrum process from ‘Inactivity’ (solution thrust upon, often with disastrous consequences), ‘Reactivity’ to ‘Pre-activity’ and ‘Pro-activity’ (resultant solution best suited to meet developing threats). Employment of UAVs is perceived in multiple roles. With varied armed configurations, armed drones or Unmanned Combat Aerial Vehicles (UVACs) are capturing the fancy of nations. Turkish-made Bayraktar TB2 UCAVs used in 2020 in the Nagorno-Karabakh war, created history in the disputed region by use of UAVs. War planners across the world have been forced to take a serious note of these weapons, their characteristics and wartime outcomes. The punch that the concept packs for surprise and damage, justifies its utility for scaling and is now an important resource for force planning and packaging.

On 14 September, drones were used to attack the Saudi state-owned Aramco oil facilities leading to a global surge in the crude oil price around the world.

On 1 January 2020, Gen Qasem Soleimani, the Iranian commander, was killed by a US drone strike at Baghdad airport. Some of the other headlines that captured the imagination of the world read – “Trump’s plane was nearly hit by a small drone”, “Ex CIA official warns of Iran, ISIS drones armed with chemical weapons”, “Warning over terrorist attacks using drones given by EU Security Chief”, “Gatwick drone disruption cost over £50 mn” and so on.

Smaller UAS, at times operating as swarms, are becoming the popular weapon of choice. Evolutionary developments in its design and utility to target important communication nerves without collateral damage, something borne in contact warfare, reflects its scalability. When relevant associated sciences like Artificial Intelligence (AI) and Deep Learning (DL) algorithms that offer disruptive outcomes are juxtaposed into the concept, the results become reverberant. Today, the UAS propel the users to a whole new level of Information, Surveillance, Target Acquisition and Reconnaissance (ISTAR) and strike capabilities. Professional armies need to be alive to this capability, be agile and pivot its advantages.

Though handled at tactical levels, the resource is strategic in its application. Grouping of UAVs in force planning is a necessity for all war entities. Based on weight, they have been categorised into Nano, Micro, Mini, Small and Large UAVs. Also, based on their operational range they are either High Altitude Long Endurance (HALE) or Medium Range Long Endurance (MALE) UAVs. Medium range ones are Tactical UAVs and the ones with smaller range are in the Mini and Nano categories.

An in-depth understanding of the characteristics, maturation level and manifestation of the drone architecture, consisting of the unmanned aircraft itself, the ground control station (GCS) and the communication data link (CDL) is necessary to design an effective C-UAS. The C-UAS for desired effectiveness must proliferate domains, technologies, operating frequencies, articulation, manifestation and orchestration and transcend interoperability and synchronization across military systems and organizations. Notably, all UAVs are drones, however, not all drones are UAVs. ‘Counter Drones’ is a science that is fast being developed as the anti-thesis to the still evolving concept of UAS.

Counter-UAS

A C-UAS system can be defined as a mechanism capable of lawfully and safely disabling, disrupting, or seizing control of the UAS. The rapid rise of commercial and military grade technologies including autonomous operations combined with concepts such as ‘Swarming’ and ‘Multi-Modal Operations’ (MMO) requires the development of effective and advanced C-UAS systems. Today, UAS are available to state and non-state actors and individuals. These systems are a low-cost, yet effective means of conducting ISR missions. The operating philosophy of C-UAS includes both detection and mitigation. To placate the palate of the ‘Techno-Doctrinaire’, both techniques are explained in some detail.

Detection Methods

Algorithms fuse data from multiple sources to produce accurate and efficient data for credible detection. Detection is undertaken through the following means:

• Electro-optical, infra red or acoustic to detect target by visual, heat or sound signatures, respectively.

• By use of radar systems. However, accuracy of the system on UAS with smaller surface area is suspect.

• By using radio frequency sensors to identify the wireless signals for control of UAS.

Acoustic Detection. Machine Learning (ML) techniques have been leveraged to classify UAS from the audio data. The signal fingerprinting of the UAS engine is constructed and analyzed. Using Convolutional Neural Networks (CNN) and Recurrent Neural Networks (RNN), detection is transformed to a binary classification for precision in identification. The technology is yet to achieve maturation, as the nature of acoustic approaches is a limiting factor, which at some stage will be addressed by ML.

Passive RF Detection. All UAS employ Radio Frequencies (RF) data link to its Command & Control (C2). The detection of UAS is derived from the spectral patterns of transmission using Software Defined Radio (SDR) receivers. Spectrum patterns are dependent on telemetry protocols that introduce errors in detection. True fix on the UAS is offered by unique signature study and vibration along with patterns of the transmitted wireless signals.

Vision based UAS Detection. Vision based detection technologies focus on Image Processing (IP). Videos and cameras are used in capturing rogue UAS images. Using computational methods, the ground station figures the appearance of UAS from the videos and pictures. The process introduces inherent challenges of distinguishing background signals from foliage and flying birds Image segmentation methods us Neural Networks (NN) to identify the UAS. A twin approach leverages the Thermal Camera to detect the UAS and NN to identify the UAS. An algorithm operating on an embedded system identifies the UAS in movement and the datasets of the pictures and videos train the algorithms to be discerning the UAS from the background. Evolution of Deep Neural Networks (DNN) in processing of image facilitates UAS detection and hold tremendous potential.

Radar based UAS Detection. Radars like Frequency Modulated Continuous Wave (FMCW), amongst all the sensors have the advantage of being time and weather agnostic. As per its principle of operation, they measure the range and velocity to provide detection.

Mitigation Methods

Mitigation technologies include the physical capture or jamming of the UAS. Jamming either through the RF Command and Control (C2) or the Global Positioning System C2 Jamming or Spoofing. UAS can also be neutralized or destroyed using guns, nets, by use of Eagles, Directed Energy or through traditional Air Defense systems. The criterion for use is ‘low cost per engagement’ and ‘least collateral damage’.

Physical Capture. In the physical capture of the UAS, soldiers fire projectiles through guns, which has nets stored in the warhead to capture a flying UAS. Directional Electromagnetic Pulse is also used to disable the control system.The method primarily focuses on disabling the mobility of Drone and control system and has the advantages of easy manipulation, lightweight and quick assembling. Itis efficient and low cost, but not pilot friendly.

Jamming. Another approach at mitigation is to jam the system or sensors rendering the UAS inoperable by the flight controller. This is the most common method at neutralizing an incoming attack. The defenders leverage signal to noise to interfere in the operation of UAS for neutralization.

Exploit Vulnerabilities. This deals with prioritizing the controls by either exploiting the vulnerabilities in the system by either use of GPS or sensor technology to alter existing protocols to control the drone and land it safely for subsequent analysis.     (contd in May 2021)