DRDO to Develop Lightweight Radar for Balloon-Based Surveillance

In a major step toward strengthening India’s surveillance capabilities, the Defence Research and Development Organisation (DRDO) has initiated plans to develop a compact, lightweight radar system specifically designed for balloon-based platforms. The project will be supported under the Technology Development Fund (TDF) scheme, with a focus on fully indigenous design and production.

Key Features of the Radar

According to the requirements outlined, the radar must meet strict Size, Weight, and Power (SWaP) constraints, as balloon platforms have limited payload capacity. The specifications include:

• Radar Technology: Preference for Active Electronically Scanned Array (AESA) radar for agile and precise detection, though mechanically scanned systems may also be considered.

• Weight & Dimensions: The system must weigh under 20 kilograms and fit into a compact structure, approximately 0.5m × 0.5m × 0.3m.

• Detection Capability:

  • Persistent surveillance within a 50–100 km range.

  • Ability to detect small radar cross-section (RCS) targets such as drones (0.01 m² RCS) at 10–20 km.

  • Tracking of over 100 aerial objects simultaneously, with target classification features like distinguishing between drones and birds.

• Operational Standards: Low power consumption (under 500 W), all-weather resilience from –20°C to +55°C, and resistance to high winds and electromagnetic interference.

• Integration: Seamless compatibility with India’s existing network-centric systems, including the Akashteer air defense control system, and data fusion with optical or infrared sensors.

• Cost & Indigenization: The radar will be developed under the 100% IDDM (Indigenously Designed, Developed and Manufactured) category, with a target unit cost below ₹10 crore.

Why Balloon-Based Platforms?

Balloon-based systems, also known as aerostats or tethered balloons, can remain airborne for long durations and provide continuous, wide-area coverage at low cost. Unlike drones or manned aircraft, balloons do not require frequent refueling and are less expensive to operate. They are particularly useful for:

• Border surveillance against low-flying drones and intrusions.

• Coastal monitoring to detect small, fast-moving objects.

• Urban security, offering persistent watch over sensitive areas.

Recent DRDO Progress

This radar initiative is part of DRDO’s broader push in lighter-than-air surveillance platforms. In May 2025, DRDO successfully tested a Stratospheric Airship Platform at an altitude of around 17 km. The test validated key systems like pressure regulation and emergency deflation, paving the way for long-endurance surveillance from the stratosphere.

In parallel, DRDO’s radar research wing is also advancing work on next-generation photonic radar technology, which promises higher precision and the ability to track very small objects—strengthening India’s layered air defense.

The Bigger Picture

Together, these projects form a multi-layered surveillance architecture:

• Low altitude balloons with lightweight radars for local monitoring.

• Stratospheric airships for long-duration, wide-area coverage.

• Advanced radars such as AESA and photonic systems for future aircraft and UAVs.

With this, India is moving closer to achieving persistent, cost-effective, and indigenous air surveillance capabilities to counter emerging threats, particularly the growing challenge of drone warfare.