Anti-
Drone : A new paradigm
Drones are one of the most exciting technological inventions that have happened in the past one decade. Drones which started with a military objective initially are now being used for civilian purpose in a number of areas as agriculture, mining, urban development, media coverage, oil and gas industry, delivery services, sports etc. The law enforcement agencies are also using drones for urban policing, traffic management, border security, disaster relief, jungle operations etc.
A Drone Policy was introduced in India
in August 2018 and this become operational from the 1st of December 2018. This
policy talks of five different categories of drones as per their weight
category, mandates the requirement of a Unique Identification number (UIN) for
each drone, talks about automatic flight termination mode, permitting of daytime
operations only, flying permission only as per visible line of sight ( VLOS)
and also a No-Permission-No-Take Off (NPNT) principle. A Digital Sky platform is
expected to give the required permissions and coordinate operations of drones.
The exponential growth in the number of drones has introduced the concept of these very drones being perceived as a threat. Miniature UAVs, consumer drones and Do-it-Yourself (DIY) drones are available all over the internet and can be easily assembled at home too. The threat from these drones could be benign when posed by a person who is unaware of the rules or by a mischief monger. There could also be a malfunction in the machine or these threats could also be a matter of design and such could emanate from the evil mind of criminals, non- state actors or anti- national elements.
The sheer versatility of drones has made them an attractive tool in the hands of anti-social and anti-national elements. Flight interruptions because of sighting of drones near airports has been heard of quite often. But there is no dearth of rogue drones up there in the sky today. Radioactive material landing on the roof of Japanese Prime Minister's office in Tokyo, French nuclear plants being surveyed by unknown drones, drone landing in the middle of meeting being taken by German Chancellor Angela Merkel, drone crashing in the lawns of White House, multiple-drone attack on the Saudi refinery, criminals using drones to send drugs, mobile phones and weapons into prisons are few such examples. Drones were used to conduct reconnaissance of Reau prison, in the outskirts of Paris, to study the security set up, after which the famous criminal Faid escaped in a helicopter. All these examples point towards a new paradigm in aerial threats.
Trials have been conducted of Anti-drone systems to counter the rogue fixed-wing planes as well as quad-copters. Techniques as listening and identifying the sound of incoming drones, using thermal imaging cameras for identification, flooding the radio frequency in which the drone is operating so as to cancel out its signal are being tested. Techniques have also been developed to hijack or take over the controls of an incoming drone. More basic techniques as shooting down an incoming drone or catching it and retrieving it in a net have also been thought of to disable rogue/enemy drones whose threat is very real today. Terrorists have also been talking about delivering bombs and other payloads as nerve gases through drones in crowds and heavily populated places to kill people and spread panic.
Companies the
world over are now trying to develop systems to counter the threat of rogue/
enemy drones. From the threats seen till date and looking at the basic
characteristics of a drone system, any counter-drone solution should
firstly be able to successfully detect and identify an incoming drone. It
should be able to distinguish between a friend and a foe and then try to
mitigate this threat by the best means available. The neutralisation of an
incoming drone should also ensure that safety is not compromised for the people
and property on ground. Any counter- drone identification system must also be
such that it does not give too many false positives. Minimum human intervention
and maximum machine understanding must lie at the core of such a system. Such a
counter- drone system can act as an effective force multiplier in the field and
can mitigate the incoming drone threats considerably.
The technology being experimented with in the counter- drone systems must also take care not to interfere with the public assigned frequencies, nor must it interfere with the frequency allotted for airplanes, cell phone communications, public broadcasts or normal radio channels. It should also not interfere with the frequency allotted to law enforcement agencies in their varied routine law enforcement functions.
In the Indian context one has recently seen a number of rogue drone ‘mules’ coming inside the Indian territory and dropping arms, ammunition and drugs near the Indo- Pak border. The Border Security Force has seized a number of suchdrones and even shot down a drone which had entered the Indian territory. Most of these enemy drones were of Chinese make and had a pre-defined flight path to drop their illegal payloads. Because of their small size they were not in a position to carry very heavy payloads of arms, ammunition or explosives which is a distinct possibility in the times to come. All these drones were light-weight, small in size, flew at a low height and at high speeds and that is why it was not possible to detect them.
Seeing this kind of a threat emerging, which is only likely
to increase in times to come, the Government of India in 2018
invited a number of local and foreign players to exhibit their counter- drone
technologies in this vital area. The idea was to set the ball rolling so that
appropriate mechanisms could be put in place to counter the threat of rogue/
enemy drones. A number of government agencies as Ministry of Civil Aviation,
Pawan Hans Limited, IAF, CISF, NSG, DRDO etc. participated in the process along
with local and foreign firms to decide on the technology best suited under
Indian conditions. On the 10th May 2019 Ministry of Home Affairs,
Government of India has also issued detailed Standard Operating Procedures for Handling the threats from Drones and other
Sub- Conventional Aerial platforms. The Ministry of Civil Aviation has also
issued National Counter Rogue Guidelines
which intend to put in place different measures and guidelines to handle the
threat posed by rogue drones. It talks of a Steering Committee at the national
level to evolve a Counter- drone framework and an Implementation Committee for
the regular monitoring of sub- conventional threat environment and the
implementation of the counter- drone measures at the national and the state
level.
II. Drone
detection and Identification
The best technology in this area will be recognized
as one that is able to identify the incoming drone, discriminate between a friend
and foe and correctly assess the threat level by looking at the database of
information available on the subject. An approaching drone can be identified in
any of the following manner:
Naked eye: The drone herein is sighted by an operator, either
with his naked eye or by sophisticated sighting instruments. The disadvantage
here is that this sighting is possible only when a drone has reached very close
to the target. It is also very difficult to identify a friendly drone from a
non- friendly one and because of the close proximity of a fast approaching
drone, it becomes very difficult to prevent any real damage or substantially
mitigate this threat.
Audio detection: All
drones emit specific frequencies and these can be picked up by a machine. The
devices that listen to these frequencies, can check on the available database,
to decide on the kind of drone approaching - whether it is a friendly or an enemy
drone etc. This audio- detection works well in any rural area but in a city/
urban setting the audio- detection gets drowned in the hustle and bustle of the
city. IIO product uses multi-
sensors as RF pulses, visual and acoustic signatures to identify rogue drones.
Radio frequency: Some counter- drone technologies are able to intercept
the radio- frequency of the incoming drone and interpret their location. Almost
all drones use some kind of RF to communicate with their operators. However
this engages drones on a one-to-one basis and this method gets thwarted when
the number of incoming drones is large. Aaronia
AARTOS DDS and De Drone product
RF100 and RF300 offer good detection in this category.
Radar: Radars have also been tried to
detect an incoming drone. However the inherent disadvantage here is that the radar
is built to detect large objects, flying at sufficient heights and approaching
at high speeds. A drone is anything but this. They are small objects, flying low
near the ground and at sufficient speeds. The recent multi- drone and missile
attacks at Abaqaiq and Khurais oil facilities in Saudi Arabia in Sept 2019 showed
that even highly sophisticated air defence systems installed by US and France were
neither able to detect nor engage the incoming drones which led to a lot of damage
to these refineries. QinetiQ,
developed by the British Army, is a very useful and mobile alert system for
incoming drones.
Geo fencing: This technology tries to create an electronic barrier in the airspace around
any vital installation or a high value target by a combination of hardware and
software. Thus a protected zone is created. Even the drone policy announced in
India by the Directorate General of Civil Aviation in 2018 clearly talks about no drone zones wherein it is prohibited
by the law to fly drones. Skyfence by
IIO builds up this kind of electronic fence.
Video detection: Video records collected over a period of time can develop valuable visual signatures to distinguish a friendly or an enemy drone. A video database can understand an incoming drone better and thereafter appropriate step can be taken to provide protection. However this methodology shows limitations and is susceptible to changes in season and changes in weather. This database built over time, supplemented by algorithms can be useful in the long-term to correctly identify and mitigate an incoming threat. IAI product Drone guard is a useful multi- sensor system using electro- optical detection for drones.
Thermal detection: This technology picks up the heat signature on any
incoming drone for identification. An urban setting is not the right place for
this technology, because there are hundreds of machines in any city. But in a
rural setting it can be a very useful tool to detect the presence of a drone in
remote areas or in counter-terrorism, counter- insurgent jungle operations.
Security of remotely located vital installations can also be done successfully
using this technology.
III. Drone neutralization
Once the drone has been detected and duly identified, a counter-drone system needs to mitigate and neutralise this incoming threat. The different methods available to counter a drone can be divided into two broad categories – Kinetic and non- Kinetic. The former are ones which use physical or brute force to neutralise this threat and these are also termed as hard kill measures while the latter are ones which try to interfere with the flight path or flight communication of an incoming drone and these are termed as soft kill measures.
(a) Kinetic solutions: The
Kinetic measure are those that physically try to intercept, damage or destroy an
incoming drone by engaging it on a one-to-one basis. This technique tracks an incoming drone,
engages it directly and then tries to render it inoperable using high powered
rays/ beams. However during such a hard kill the enemy drone gets destroyed and
attempts to collect electronic evidence, which can point towards its perpetrator
are lost.
Counter drone drones:
These are drones that are
available with the law enforcement or counter- drone forces on the ground to
counter the rogue/ enemy drone. They engage an incoming drone on a one-to-one
basis and try to overpower/ crash into the incoming drone. By causing a
collateral damage, this technique can also sometimes pose a risk to people and
property where the destroyed drone hits the ground. However this technique is
not very successful, if the number of incoming drones is large or it was a
centrally- coordinated swarm of drones. Counter
UAS by Skylord is an effective system in this category.
Eagles: The
use of predatory birds to counter drones was also tried. Eagles which are
natural predators, were trained to intercept incoming drones. The Dutch law
enforcement started using this technique to pluck out enemy drones from the
air. The eagles because of their big wingspan, keen eyesight and sharp talons
were quite successful in this. However to
counter this defence, some rogue manufacturers started putting sharp edges on
the rotors which hurt and injured these birds. Inconsistent
behavior shown by the birds also come in the way and now this technique has almost
been shelved.
Nets: Attempts
have made to intercept enemy drones by putting a net over them which will interferes
with the rotating blades and this will bring the drone down. The advantage of
this technique is that the complete drone is rendered inoperable and it cannot
fly any longer. Once available, the rogue drone can be scanned for all the
electronic evidence, to trace the digital footprints, and ultimately its source
and intent. Since the drones are very small flying objects, moving at a
reasonably good speed and can change directions it becomes very difficult to
accurately target it so that a net can be placed around it, rendering it
immobile. The Drone Catcher is a
drone which approaches the enemy drone, locks onto it and then catches the
enemy drone by throwing a net around it. Similarly the Skywall 100 is
a grounded version of the Drone catcher wherein a ground- based gun fires a net
at the suspect drone to bring it down.
Projectiles: Projectiles are also fired at approaching drones to destroy
them completely. These high precision guided projectiles can lock on to the
target and obliterate them completely. The variants of this technology range
from the very cheap ones, which are not very effective, to the highly expensive
missiles which can destroy a drone completely by engaging it on a one-to-one
basis. These can prove useful while protecting vital installations or very high
value targets. Since drones are very small objects, flying close to the ground
and changing directions, targeting them can be a challenge. Similarly, if a drone
is light weight it will not be able to carry a very heavy payload and therefore
its potential for a big damage will also be low.
Lasers: Companies
have also tried to bring down the enemy drone by firing very high powered laser
beam at an incoming drone. This high powered beam is capable of destroying the
drone completely or at least damaging the critical parts thereby rendering it
useless. However adverse weather conditions can come in the way of effective
engagement of lasers. The limitation is that lasers, which require a large
amount of power to operate, can only fire in the visual line of sight. The
falling of the damaged enemy drone on the ground also poses risks to the people
and property nearby. DRDO’s anti- drone
system is a comprehensive solution to damage rogue drones by firing high
wattage laser at them. ATHENA, used by the US Army, is a weapon that
targets big drones by firing a high energy laser beam and completely destroying
the enemy drone. Similarly the Death Ray
truck, developed by Boeing, fires high energy laser at targets and destroys
them in all weather conditions.
(b) Non Kinetic Solutions: These techniques try to counter the threat posed by the incoming drone by intercepting or interfering with the communication system between the drone and its operator and ultimately taking control of the rogue drone.
Jammers: The
jammer blasts high intensity electromagnetic signals at the frequency on which
the drones operate. This interferes with the navigation and communication of an
incoming drone and disorients the drone. This high intensity signal disrupts the
communication between the drone and its operator and renders the drone
immobile. The jamming frequencies must be carefully chosen so that they do not
interfere with public assigned frequencies and also do not interfere with
aircraft movement, cell phone usage, public broadcasts etc.
Directional jammers have been developed which lock an incoming drone in a one-to-one engagement and try to jam its systems. But if the number of drones is large, or if they are operating at different frequencies, then it is a challenge. Manufacturers, to counter such jammers, are trying to introduce high end encryption to counter the jamming technologies in the new class of drones. However the research agencies have now introduced the concept of Barrage jammers which jam communications over a wide range of frequencies so that these can also operate on a one-to-many basis and one such equipment can jam the frequencies of a number of drones flying at different frequencies. By jamming the rogue drones they can be safely brought to ground for further analysis. Drone gun MkIII jams the radio/GPS/ mobile signal between the drone and the pilot and is able to ground a suspect UAV. This weapon, designed in Australia, has an effective range of about 2 kms. Dynamatic’s Anti- drone system and Sky Fence are two good products which use a range of signal disruptors to jam the flight path of suspect drones and thus prevent them from entering secure and sensitive places as vital installations.
Spoofing: This is a very effective way to gain control of an incoming
drone by intercepting the communication between the controller and his drone
and then replicate and clone it in a manner so that another person is able to take
over the control. Drone Malware implies
hacking of the suspect drone by planting a malware remotely, taking control of
its software and pilot and thereafter taking it in custody. Drone defender is another very useful
product in this category.
These counter- drone technologies can identify and engage multiple
drones at one time. They can all operate on a 24x 7 basis and are not limited to
visual line of sight or day-night restrictions. They can truly prove to be a
force multiplier in the field. Some of these technologies can even avoid
collateral damage by taking over control of an incoming drone, thereby not only
protecting the any vital installation from damage, but also facilitate a
detailed analysis of the complete digital footprint that the enemy drone
carries.
IV.
Conclusion
No counter-drone solution is
perfect. The disadvantages of one counter-drone system can be overcome by
combining two or three different systems together. The basic objective behind any
counter- drone technology is that it should be able to detect the presence of an
incoming drone, should successfully identify a friend or a foe and finally try
to reduce the damage in the best way possible manner so that the safety and
security of the people living around is not compromised. These drones must not
only be neutralized in the best manner possible, but attempts must also be made
to collect as much evidence from them as possible because only then can an
enemy/ rogue non-state actor be confronted with incontrovertible evidence as
per the law of the land. The drone policy enunciated by the Government of India
in the year 2018 is a very useful tool in this direction and its compliance
needs to be ensured all over the country if we are to mitigate the risks of
enemy/ rogue drones and make people/ vital installations safe.
(
3268 words )
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Author :
Pankaj Kumar Singh IPS
Addl DG BSF
Eastern Command, Kolkata
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