The Arudhra Radar Indian Navy variant cleared by the Defence Acquisition Council on Monday will replace ageing Air Route Surveillance Radars at various naval air stations, part of a Rs 1.10 lakh crore round of Acceptance of Necessity approvals spanning the Army, Navy and Air Force.

Arudhra is a medium power radar designed by the Electronics and Radar Development Establishment, a DRDO laboratory, and manufactured by Bharat Electronics Limited.

Public specifications describe it as a 4D active phased array radar operating in the S band, with electronic steering in both azimuth and elevation rather than the mechanical rotation older radar generations relied on. The system carries an instrumented range of about 400 kilometres and can detect a target with a radar cross section as small as 2 square metres at roughly 300 kilometres. Altitude coverage runs from around 100 metres up to 30 kilometres, letting a single installation watch for both low flying threats and high altitude traffic.

How the Arudhra Radar Indian Navy variant operates

Arudhra operates in two modes.

A 360 degree rotation mode cycles at 7.5 to 15 rpm for broad area surveillance, while a staring mode locks onto a 60 degree sector either side of a chosen bearing for closer tracking of a specific threat axis. Built in electronic counter countermeasures are meant to keep the radar functioning under jamming, and a co located Identification Friend or Foe system helps distinguish friendly aircraft from unknown contacts.

Where Arudhra has already been inducted

The Arudhra Radar Indian Navy variant is not a new system entering service for the first time under a different name. The Air Force placed an order for Arudhra in 2023, in a contract worth more than Rs 2,800 crore, procured under the Buy Indian, Indigenously Designed Developed and Manufactured category. That induction has continued as an upgrade to the IAF's air surveillance network, replacing older radar types nearing the end of their service life.

Arudhra belongs to a small family of indigenous DRDO designed radars now in service or under contract. Ashwini, a low level transportable radar, was the subject of a separate Rs 2,906 crore deal with Bharat Electronics Limited in 2025, built to track fast jets as well as slower and low flying targets such as drones and helicopters. Rohini, a ground based mechanically scanning radar, covers medium range airspace surveillance and early warning at airbases, with a tracking range BEL puts at around 150 kilometres.

What Monday's naval clearance adds

The naval requirement is a distinct variant, aimed at Air Route Surveillance Radars at various naval air stations rather than the Air Force's air defence network.

It replaces ageing surveillance equipment used to monitor air traffic and manage airspace around naval air stations, a role distinct from air defence radar but essential to safe flight operations at any active airfield handling fixed wing patrol aircraft and shipborne helicopters alike. The official release grouped the Arudhra clearance with the design and development of Marine Gas Turbines under the Navy's share of Monday's AoNs.

The move continues a pattern in India's radar procurement, where a system developed and inducted for one service is later adapted for another rather than each service commissioning a fresh design. This also keeps the naval air station upgrade within the Aatmanirbhar Bharat framework applied across Monday's Rs 1.10 lakh crore clearance, where about 98 percent of the procurement value is set to be sourced from Indian industry, one of the highest domestic sourcing shares on record for a single AoN round.

The stealth detection question

A simulation circulated earlier this year showed Arudhra tracking a modelled F-35 within the Integrated Air Command and Control System, drawing on the radar's beam steering and processing to expose a stealth signature under controlled conditions.

That result came from a computer based modelling exercise, not a live tracking trial, and no confirmed operational detection of an actual F-35 or comparable stealth aircraft has been reported. Arudhra is one part of a wider layered radar and sensor push, alongside Ashwini and Rohini, that officials have linked to a broader effort to build a networked capability against low observable aircraft.

A radar family built on repeat orders

The pattern across Arudhra, Ashwini and Rohini is repeat business for the same design and production chain rather than one off orders.

Each order has followed the same route: an LRDE design, a BEL production contract, and a service specific requirement layered onto a common radar architecture. The naval Arudhra order follows that same route again, and it comes roughly two months after a separate Rs 52,000 crore round of AoNs the council cleared in July, when MRSAM, V-SHORADS and the newly named AKASH TARANG anti UAV system were the headline items on the Army side.