Defence Technology

Context: The Indian Army has initiated the procurement of a new range of advanced Air Defence (AD) radars to strengthen its surveillance and strike capabilities along the Northern and Western borders.

Relevance of the Topic: Prelims: About radar and its working.

This step comes in the aftermath of Operation Sindoor (May 2025) during which some Pakistani drones intruded into Indian airspace which exposed serious gaps in India’s air defence coverage. 

What is Radar? 

• Radar is the acronym for RAdio Detection And Ranging.
• It is a specialised electronic system that uses radio waves to determine the direction, distance, and velocity of target objects. 
• Air Defence radars are used by the military to search, detect, identify, and help destroy aerial threats.

How Radar Works? 

• A radar comprises two basic components: Transmitter and Receiver.
• A transmitter sends out radio signals, and a receiver collects any reflected signals from the target. 
• The angular direction of a target is determined based on the direction from which the reflected signals are received. The measurement of the location of a target at successive moments helps calculate its trajectory. 

There are primarily two kinds of Air Defence Radars: Surveillance radars and Fire control radars.

• Surveillance Radars: These constantly scan the skies to detect aerial objects. They provide early warning but are not directly linked to weapon systems.
• Fire Control Radars: These provide precise tracking data to guide surface-to-air guns and missile systems for neutralising threats.

Current Air Defence Radar Capabilities in India: 

• Both the Army and the Indian Air Force (IAF) operate surveillance and fire control radars. The IAF manages most High Power Radars (HPRs) and Medium Power Radars (MPRs).
  • They can detect and track aerial threats several hundred kilometres away, especially at higher altitudes.
  • These radars are essential against high-value threats such as fighter jets, enemy transport aircraft, and Airborne Warning and Control Systems (AWACS).
• Both the IAF and Army also operate Low Level Light Weight Radars (LLLRs), which are designed to detect smaller aerial objects flying at low altitudes.
• For fire control, the IAF uses the 3D Central Acquisition Radar and the Rajendra Radar, while the Army primarily employs Flycatchers (indigenously upgraded Super Fledermaus) and the Air Defence Tactical Control Radar.

Issues with the Existing Infrastructure: 

• Many of the Army’s radars are aging and inadequate for detecting low-RCS drones and UAV swarms. 
  • The Radar Cross Section (RCS) is a measure of how detectable an object is to radar, usually expressed in square metres. A lower RCS makes an object harder to detect.
• During Operation Sindoor (2025), Pakistan used hundreds of drones, including decoys and attack UAVs, to breach Indian airspace and expose system vulnerabilities.

Experiences from conflicts in Ukraine and Gaza show that traditional air defence systems are easily overwhelmed by swarms of drones and stealthy aerial objects, underscoring the urgent need for modernised detection and response systems in India.

The Army has sought to procure up to 45 Low Level Light Weight Radars (Enhanced), up to 48 Air Defence Fire Control Radar-Drone Detectors (ADFCR-DD), and 10 Low Level Light Weight Radars (Improved). 

Significance: 

• These systems will specifically address challenges posed by small, low-flying, and low- Radar Cross Section (RCS drones) which older radars struggle to detect.
• Enhanced LLLRs will provide accurate detection and transmit target data to weapons up to 10 km away.
• ADFCR-DDs will allow identification, classification, and engagement of even the smallest drones, thereby making counter-drone operations more effective.

The procurement of advanced AD radars enhances India’s preparedness against emerging aerial threats and supports the creation of a seamless multi-layered defence shield envisioned under Mission Sudarshan Chakra.

Context: Indian Navy commissioned two Project 17-A stealth frigates, INS Udaygiri and INS Himgiri, in Visakhapatnam. This marks the Navy's first-ever simultaneous induction of two frontline warships.

Relevance of the Topic: Prelims: Key facts about Project 17-A; INS Udaygiri; INS Himgiri. 

What are Stealth Frigates?

• Frigate is a medium-sized warship used by the Navy for escorting larger vessels, patrolling, and combat operations.
• Stealth frigate is designed with advanced stealth technology to minimise its radar cross-section and overall visibility to enemy detection systems making it harder to detect by radar, visual, sonar, and infrared methods. 

Project 17-A Stealth Frigates: 

• Project 17-A class (Nilgiri-class frigate) is the successor of the currently-operational Project 17 or the Shivalik-class stealth frigates. 
• The stealth frigates have advanced weaponry, modern sensor systems designed to execute a full spectrum of maritime operations in blue-water conditions.  
• The project will have 7 frigates. INS Nilgiri is the lead ship of the Project 17A stealth frigate class. Other six ships of this class include- INS Udaygiri, Himgiri, Taragiri, Dunagiri, Vindhyagiriand Mahendragiri.
  • INS Udaygiri (second ship of Project 17A) is built by Mazagon Dock Shipbuilders Ltd. in Mumbai. 
  • INS Himgiri is constructed by Garden Reach Shipbuilders & Engineers (GRSE) in Kolkata. 

INS Udaygiri & INS Himgiri

• Enhanced capability: Both vessels are follow-on variants of the Shivalik-class frigates. They feature enhanced stealth capabilities, advanced weaponry, and modern sensor systems. 
• Propulsion: Both frigates are powered with combined diesel or gas (CODOG) propulsion using diesel engines and gas turbines that drive controllable-pitch propellers, and are managed through an integrated platform management system.
• The frigates are capable of dealing with both conventional and non-conventional threats. The frigates are fitted with:
  • Supersonic Surface-to-Surface Missile system
  • Medium Range Surface-to-Air Missiles (MRSAM) system
  • 76 millimetre (mm) upgraded gun
  • Combination of 30 mm and 12.7 mm rapid-fire close-in weapon systems
  • Anti-submarine underwater weapon systems.
• Sensors suite include MF-STAR AESA radar, BEL’s HUMSA-NG sonar, the Ajanta electronic warfare system and the CMS-17A combat management system. 
• Protective systems include the Kavach anti-missile decoy and the Maareech torpedo decoy.
• Enhanced stealth features: Radar cross-section is reduced through angled surfaces and flush-mounted weapons. Heat emissions are cut using infrared suppression systems. Noise is lowered with improved acoustic dampening. Use of composite materials contributes to making these ships less visible and less audible at sea.
• Each ship can support aircraft such as the MH-60 Romeo, ALH Dhruv Mk-III or Sea King.

Significance: 

• Force-multiplier: With their versatile weapons and capabilities, these ships can play a crucial role in anti-surface, anti-air, and anti-submarine warfare. With their range and helicopter integration, they can patrol waters stretching from the Strait of Malacca to Africa, keeping sea trade routes secure.
• Indigenous development: With nearly 75% indigenous content, supported by several MSMEs, the frigates advance the government’s Aatmanirbhar Bharat vision in defence manufacturing.
• Employment generation: The project reflects the scale of India’s defence industrial ecosystem, involving over 200 MSMEs and generating nearly 14,000 direct and indirect jobs.

The ships will be deployed with the Eastern Fleet, significantly boosting the Navy’s combat readiness and reinforcing India’s ability to protect its strategic and economic interests in the Indian Ocean Region.  

Context: DRDO has conducted the maiden flight test of the Integrated Air Defence Weapon System (IADWS) off the coast of Odisha. 

Relevance of the Topic: Prelims: Features of Integrated Air Defence Weapon System (IADWS). 

Integrated Air Defence Weapon System (IADWS)

IADWS is a multi-layered air defence system comprising: 

• Indigenous Quick Reaction Surface-to-Air Missiles (QRSAM)
• Advanced Very Short Range Air Defence System (VSHORADS) missiles 
• A high-power laser-based Directed Energy Weapon (DEW) 

Three components of IADWS

Indigenous Quick Reaction Surface-to-Air Missiles (QRSAM): 

• QRSAM is a short-range Surface to Air Missile (SAM) system. It is primarily designed to provide a protective shield to moving armoured columns of the Army from enemy aerial attacks.
• The entire weapon system is configured on highly mobile platforms. It has search and track capability and can fire on short halts. The system has an operation range of 3 to 30 kilometers. 
• The QRSAM weapon ensemble consists of a fully automated command and control system, two radars (Active Array Battery Surveillance Radar and Active Array Battery Multifunction Radar) and one launcher. Both the radars have a 360-degree coverage with ‘search on move’ and ‘track on move’ capabilities. 

Advanced Very Short Range Air Defence System (VSHORADS) Missiles: 

• VSHORADS is a fourth-generation, technically advanced miniaturised Man Portable Air Defence System (MANPAD). 

• The weapon system can neutralise targets between the range of 300 meters and six kilometers, including drones and other classes of aerial threats.
• Effective against drones, UAVs, and low-flying aircraft. Designed for all three services: Army, Navy, Air Force. 

Directed Energy Weapon (DEW): 

• High-power laser-based weapon (range < 3 km).
• Neutralises UAVs, swarm drones by structural damage & disabling sensors.
• Places India in the exclusive group of nations with operational DEWs.

While QRSAM has been designed and developed by the DRDO, VSHORADS and DEW have been developed by Research Centre Imarat (RCI) and Centre for High Energy Systems and Sciences (CHESS) respectively, both Hyderabad-based facilities of the DRDO.

Centralised Command and Control Centre: 

• The integrated operation of all these weapon system components is controlled by a Centralised Command and Control Centre, developed by the Defence Research and Development Laboratory, Hyderabad.

Strategic Significance of IADWS

• Enhanced Air Defence: Provides a multi-layered shield against UAVs, drones, and short-range missiles up to 30 km, strengthening national security.
• Indigenous Capability: Showcases India’s self-reliance in defence technology, reducing dependence on foreign imports.
• Network-Centric Warfare: Will integrate with IAF’s Integrated Air Command and Control System (IACCS) and Army’s Akashteer, improving jointness and real-time coordination.
• Counter to Modern Threats: Combines missiles with Directed Energy Weapons, enabling defence against drone swarms and asymmetric aerial attacks.
• Strategic Deterrence: Enhances India’s credibility to deter Pakistan’s drone incursions and China’s UAV warfare capabilities.
• Mission Sudarshan Chakra: Marks an important step towards developing a indigenous nationwide security shield from multi-dominary enemy attacks under Mission Sudarshan Chakra by 2035. 

Context: Recently, India successfully test-fired its nuclear-capable intermediate range ballistic missile (IRBM) Agni 5 from the integrated test range (ITR) at Chandipur in Odisha.

Relevance of the Topic:Prelims: Key facts about Agni 5 missile; Agni Missile series. 

About Agni 5 missile

• Developed by: Defence Research and Development Organisation. 
• Agni-5 is among India’s most advanced long-range ballistic missiles. Equipped with modern navigation, guidance, warhead and propulsion technologies, it strengthens India’s nuclear deterrence.

Key features of Agni 5 missile:

• Nuclear-capable ICBM: Agni 5 is a land-based Intercontinental Ballistic Missile (ICBM) with Multiple Independently Targetable Reentry Vehicle (MIRV) capability.
• Extended range: Designed for nuclear use, Agni 5 has a range of over 5000 kilometres.
• Propelled by a solid rocket propellant system. Agni 5 is powered by a three-stage solid-rocket-powered missile system capable of delivering a 1.5-tonne nuclear warhead.
• MIRVed test launch: In 2024, India conducted the first MIRVed test launch of Agni 5 from validating its ability to carry and release multiple warheads.
• Warhead capacity: Capable of carrying and firing up to 3 nuclear warheads simultaneously.
• Future enhancements: New variants under development aim to integrate bunker-buster bomb technology, expanding the missile’s strike capability against fortified targets.

Key Facts: 

• India’s missile development accelerated after it joined the Missile Technology Control Regime (MTCR) in 2016 gaining access to advanced systems.
• India has a no-first use policy for nuclear weapons, hence, the missile can offer incredible deterrence to prevent a nuclear attack.

The successful test reaffirms India’s commitment to maintaining a credible minimum deterrence posture. 

Also Read: Mission Divyastra: Agni-V with Multiple Warhead Technology