The Indian Air Force is moving to procure advanced long-range surveillance radars (LRSR) to replace older generation systems, some of which have been in service since the mid-1970s.

This initiative reflects the growing importance of a multi-tiered air defence network in modern warfare, particularly given the proliferation of diverse aerial systems and missiles.

The IAF has specified its requirement for a mobile, vehicle-mounted system capable of detecting and tracking ballistic and cruise missiles, aircraft, and drones with low radar cross sections, high speed, and high altitude profiles.

The system should operate at ranges exceeding 450 kilometres and altitudes up to 40 kilometres. It must also automatically classify targets into categories such as large, medium, and small fixed-wing aircraft, rotary-wing aircraft, and UAVs.

The radar is expected to be a four-dimensional (4D) electronically scanning phased array system based on Gallium Nitride (GaN) technology. It will integrate an identification friend or foe (IFF) system and deliver a high-quality air situation picture with 360-degree coverage. The system must withstand extreme environmental conditions, ranging from minus 40 degrees Celsius to 50 degrees Celsius, and be deployable at altitudes of up to 16,000 feet.

In addition to the main radar, the request for information (RFI) issued on 8 April stipulates the inclusion of an X-band radar co-located on the main antenna vehicle for drone detection, with a fused display. 

The RFI is restricted to Indian entities. The emphasis on drone and missile detection reflects lessons from Operation Sindoor in 2025, where these platforms played a central role in combat against Pakistan.

GaN technology, which replaces traditional silicon, is characterised by high power efficiency, reduced heat generation, and high-frequency switching. Though first developed in 1932, it only became commercially viable in the mid-2000s, with widespread use from 2018 onwards.

India joined the select group of nations capable of producing GaN chips in 2023, when the Defence Research and Development Organisation (DRDO) achieved indigenous production for defence applications.

Currently, the Indian Armed Forces employ over two dozen types of surveillance radars of both Indian and foreign origin. These systems monitor airspace at the strategic level and protect vital assets and tactical battle areas at medium and short ranges.

The longest-range radar in service is the High Power Static Radar, developed by France’s Thomson-CSF and manufactured by Bharat Electronics Limited (BEL), which has a reach of 430 kilometres and an altitude coverage of 75,000 feet. It was inducted in 1976.

In 2025, the IAF began inducting the Surya anti-stealth radar developed by DRDO, with a range of 360 kilometres. That same year, the force ordered 16 Arudhra Medium Power AESA radars, also developed by DRDO and manufactured by BEL, with a range of 400 kilometres. In 2024, Larsen and Toubro secured an order for 12 static high-power radars, reportedly with ranges exceeding 400 kilometres.

Over the past two decades, both the IAF and the Indian Army have inducted radars with ranges from 4 kilometres to 260 kilometres to meet varied operational requirements. These systems are designed to track large aircraft as well as small, low-flying objects. Some are 4D capable, measuring not only distance, speed, and direction but also the vertical height of targets.

To address surveillance gaps along the Himalayan frontier, the IAF recently placed orders with BEL for mountain radars. These systems are tailored to detect low-flying aircraft, drones, and stealth platforms in high-altitude environments, further strengthening India’s layered air defence network.

Agencies