Explained: India's drone policy, threats posed by rogue UAVs and how they can be neutralised

The first-of-its-kind attack by purported drones at the air force in Jammu prompted Prime Minister Narendra Modi to hold a meeting that included Union home minister Amit Shah and defence minister Rajnath Singh to discuss the framing of a policy response to check against security threats posed by the use of unmanned aerial vehicles (UAVs).

India has guidelines in place for civilian use of drones, but the Jammu attack has shown the need for tightening rules and response strategies to provide a clear deterrence against any such attacks.

What are the rules on drones in India?

In March, the Ministry of Civil Aviation notified the Unmanned Aircraft System Rules that govern the operation of drones and similar systems in India.

These rules follow the Civil Aviation Requirements (CAR) for drones that were issued by the Directorate General of Civil Aviation (DGCA) in 2018.

Weight is the primary basis by which the rules classify drones vis-a-vis the specific rules governing their operation. Thus, 'Nano' unmanned aircraft are those that weigh less than or equal to 250gm while 'Micro' drones are those weighing more between 250gm and 2kg.

'Small' drones can weigh more than 2kg but should not exceed 25kg. 'Medium' drones can weigh between 25kg and 150kg and 'Large' unmanned aircraft are those that weigh more than 150kg.

For operating any of these drone types, except for the Nano models, permission is required from the Director General of Civil Aviation.

Several checks and bans are built into the rules to prevent drones posing a security threat. For example, all drones have to mandatorily contain autonomous flight termination system or return to home (RTH) option and should also come with geo-fencing mechanism. Geo-fencing systems provide a means for restricting the movement of a drone for a real-world geographic location using the global positioning system (GPS) or radio frequency identification.

Further, all drones, except Nano models, will have to have a tamper-proof 'No Permission–No Takeoff (NPNT) mechanism. This system will ensure that every drone has to obtain a valid approval from DGCA via an app or the procedure created for the purpose before it can be operated. There are also no-fly areas for drones that include airports, strategic locations, and the LoC with Pakistan and LAC with China, etc.

There is also the requirement for mandatory registration of drones, except Nano drones, with DGCA.

However, the attack in Jammu was likely a case of rogue drones dropping explosives and, hence, the civil aviation ministry guidelines leave open the question as to what the response will be to rogue actors operating drones to carry out attacks.

What are the threats posed by rogue drones?

As it became increasingly apparent that drones can pose a considerable security threat, the civil aviation ministry in 2019 put together guidelines for countering rogue drones.

It identified three specific types of drones on the basis of the threat profile: autonomous drones, which are controlled by on-board computers and don't need to be manually operated; drone swarms, which can be used in attacks by simultaneously launching and controlling multiple drones using coordination software; and stealth drones that can be made to evade radar and other means of detection.

Such drones, the guidelines say, can be used for smuggling, reconnaissance, or to carry out various types of attack, targeting VIPs, crowded areas or other aircraft.

How can the threat from drones be neutralised?

The rogue drone guidelines note that conventional air defence systems are "generally ineffective against drones" and that military radars are designed to track larger, fast-moving aircraft and "cannot always pick up small, slow, low-flying drones".

Importantly, it is not cost effective to use expensive anti-aircraft systems to shoot down these drones, which are typically cheap and can be easily devised.

What an effective counter unmanned aircraft system (C-UAS) needs, therefore, is an ability to detect and track all kinds of drones, including the ones that have low radar and infrared footprint. Along with that it should be able to quickly identify and classify whether a drone is friendly or hostile. Finally, comes the requirement of engaging and defeating a rogue drone in a timely and cost-effective manner.

Depending on the location and asset being protected, the rogue drones guidelines suggest a three-tier approach to guarding against drones. The 'full-scale model' is the top priority level and covers sites like the Parliament, Rashtrapati Bhavan, nuclear installations, airports, etc.

It envisages a protective cover that includes primary and passive detection systems like radar, radio frequency detectors, electro-optical and infrared cameras. For the task of neutralising drones these sites can have both 'soft kill' systems, like radio frequency jammers, and 'hard kill' mechanisms like high-powered electromagnetic and LASER weapons, drone-catching nets, etc.

For installations such as oil refineries andpower stations, the guidelines recommend a 'mid segment model' that includes primary and passive detection and soft kill options. The 'basic model' is for locations like important government offices, national monuments, and includes only passive detection like radio frequency trackers while it is recommended that the security on the premises can use their conventional weapons to shoot down drones.

In the wake of the Jammu drone attack, reports have suggested that the Defence Research and Development Organisation (DRDO) has already put together a counter drone system that incorporates many of the strategies discussed in the rogue drone guidelines.