India's defence research establishment has achieved a significant milestone with the advancement of the Anti-Stealth VHF-SR (Very High Frequency-Short Range) surveillance radar system into critical field trials, representing a transformative leap in indigenous radar technology.

Developed through a collaborative effort between the Defence Research and Development Organisation (DRDO), Bharat Electronics Limited (BEL), and TATA Advanced Systems Limited (TASL), this cutting-edge radar system demonstrates India's growing prowess in developing sophisticated counter-stealth technologies. 

The system's entry into field trials marks a pivotal validation phase where performance parameters including low radar cross-section (RCS) target detection range, angular resolution, and tracking accuracy against stealth platforms are being rigorously assessed under real operational conditions. With an impressive 400-kilometre detection range and capability to simultaneously track up to 100 targets using advanced Gallium Nitride (GaN) transmit-receive modules, this radar system represents a quantum leap in India's air defence surveillance capabilities.

Technical Specifications And Sophisticated Capabilities

The VHF-SR surveillance radar incorporates state-of-the-art technical specifications that position it among the world's most advanced anti-stealth detection systems. The system's remarkable 400-kilometre detection range represents a considerable achievement for a truck-based mobile VHF radar platform, enabling comprehensive early warning and surveillance capabilities across vast operational areas. This extended range capability significantly enhances air defence networks by providing substantial lead time for threat assessment and response coordination. The radar's ability to simultaneously track up to 100 targets demonstrates sophisticated signal processing capabilities and advanced computational algorithms that can manage multiple threat scenarios concurrently.

Central to the system's advanced performance are the Gallium Nitride (GaN) transmit-receive modules, which represent the latest evolution in radar technology. These GaN-based modules offer superior power efficiency, enhanced reliability, and improved thermal management compared to traditional gallium arsenide technologies. The incorporation of distributed architecture with integrated transmit-receive modules using solid state technology ensures efficient scan coverage, beam agility, and high system reliability. This technological foundation enables the radar to maintain consistent performance across diverse operational environments while providing the power output necessary for long-range detection of low-observable targets.

The system features a unique "staring capability" that enables continuous surveillance of designated airspace sectors, providing uninterrupted monitoring of potential stealth targets at extended ranges. This capability represents a significant advancement over conventional scanning radars, as it allows for persistent observation of critical areas without the temporal gaps inherent in rotating antenna systems. The staring mode enhances detection probability for intermittent or low-signature targets that might otherwise escape detection during brief scanning intervals.

Stealth Detection Technology And Counter-Measures

The VHF-SR radar's primary technological advantage lies in its ability to detect very low observable (VLO) aircraft, including advanced stealth fighters that are specifically engineered to evade conventional radar systems. Operating within the VHF band (30 to 300 MHz), the system exploits fundamental physics principles that make stealth technology less effective against longer wavelength radiation. Conventional radar systems typically operate at higher frequencies and shorter wavelengths, which stealth aircraft are specifically designed to deflect or absorb through advanced materials and geometric shaping techniques.

The longer wavelength characteristics of VHF radar create a fundamental challenge for stealth technology, as the radar cross-section reduction techniques optimized for higher frequency systems become less effective. Stealth aircraft achieve low observability primarily through careful shaping to redirect electromagnetic energy away from the transmitting radar and through radar-absorbing materials designed for specific frequency ranges. However, these countermeasures are less effective against VHF wavelengths, which can interact with aircraft structures in ways that produce detectable radar returns despite stealth design features.

This capability is particularly significant in the context of emerging regional threats, specifically the potential acquisition of Chinese-made J-35A stealth fighters by neighbouring countries. The VHF-SR radar's ability to detect such fifth-generation fighter aircraft provides a critical advantage in scenarios where conventional radar systems might fail to provide adequate early warning. The system can detect stealth aircraft as they lift off from forward airbases, providing valuable response time for defensive measures and tactical decision-making.

Operational Deployment And Mobility Features

The VHF-SR radar system's operational effectiveness is significantly enhanced by its mobile deployment configuration, mounted on two TATRA vehicles that provide exceptional strategic flexibility and rapid deployment capabilities. This mobile platform approach enables quick relocation to different operational positions, adapting to dynamic threat environments and evolving tactical requirements. The use of TATRA vehicles, known for their rugged construction and all-terrain capabilities, ensures that the radar system can be deployed in diverse geographical conditions, from mountainous border regions to coastal surveillance positions.

The mobility factor proves particularly valuable for a nation like India, which must secure extensive and geographically diverse borders requiring responsive and flexible defence systems. The ability to rapidly reposition the radar system allows for adaptive coverage patterns that can respond to intelligence inputs, emerging threats, or changing operational priorities. This mobility also provides survivability advantages, as the system can be relocated to avoid potential counter-attacks or to maintain operational security through unpredictable positioning.

The system's design incorporates considerations for transportability and deployment in challenging terrain conditions. Following the established DRDO tradition of developing antenna systems that are segmented for man/mule transportability in mountainous regions, the VHF-SR radar maintains operational effectiveness while ensuring practical deployment capabilities. This design philosophy ensures that the radar can be effectively utilized across India's diverse operational environments, from high-altitude border regions to coastal defence positions.

Field Trials And Validation Process

The current field trial phase represents a critical milestone in the VHF-SR radar's development lifecycle, focusing on comprehensive performance validation under realistic operational conditions. These trials are designed to assess key performance parameters including low RCS target detection range, angular resolution capabilities, and tracking accuracy against challenging low-observable targets. The validation process involves systematic testing across various operational scenarios to ensure the system meets specified performance requirements and can effectively fulfil its intended mission roles.

The field trial methodology incorporates evaluation of the radar's performance against diverse target types, including both conventional aircraft and simulated low-observable platforms that represent the stealth threat spectrum. Testing protocols examine the system's ability to maintain track continuity on low RCS targets, assess false alarm rates, and validate the multi-target tracking capabilities under various electromagnetic environments. These comprehensive evaluations ensure that the system can perform reliably in complex operational scenarios where multiple factors may affect radar performance.

Performance validation extends beyond basic detection capabilities to include assessment of the system's integration with broader air defence networks and command and control systems. The trials evaluate data link performance, target hand-off procedures, and coordination with other sensor systems to ensure seamless integration into existing defence architectures. This comprehensive approach ensures that the VHF-SR radar will function effectively as part of an integrated air defence system rather than as an isolated capability.

Technological Innovation And Manufacturing Excellence

The VHF-SR radar incorporates numerous technological innovations that demonstrate India's advancing capabilities in complex radar system development. The system's electronics and signal processing capabilities represent significant achievements in indigenous technology development, particularly in areas such as advanced algorithms for low RCS target detection and sophisticated signal processing techniques for multi-target tracking. These technological advances build upon decades of research and development by LRDE and other DRDO establishments in radar technology and electronic systems.

The manufacturing collaboration between BEL and TASL brings together complementary capabilities in electronics manufacturing and system integration, ensuring that the radar system meets stringent quality and performance standards. BEL's expertise in defence electronics manufacturing, combined with TASL's system integration capabilities, creates a robust production foundation for the VHF-SR radar program. This collaboration demonstrates the effectiveness of combining public sector research capabilities with private sector manufacturing expertise to deliver advanced defence systems.

The successful development of the VHF-SR radar also showcases India's growing mastery of critical technologies including GaN-based transmit-receive modules, advanced antenna design, and sophisticated signal processing algorithms. These technological capabilities have broader applications across multiple defence platforms and represent valuable intellectual property that can be leveraged for future radar development programs. The technology base established through this program provides a foundation for continued advancement in radar technology and anti-stealth capabilities.

Conclusion

The DRDO-BEL-TASL VHF-SR anti-stealth surveillance radar represents a transformative advancement in India's defence capabilities, successfully transitioning from development phase to critical field trials that will validate its operational effectiveness. With its impressive 400-kilometre detection range, capability to simultaneously track 100 targets, and advanced GaN transmit-receive modules, the system demonstrates India's growing technological sophistication in developing cutting-edge defence systems. The radar's unique ability to detect stealth aircraft through VHF technology addresses a critical capability gap and provides strategic advantages in countering advanced aerial threats.

The successful progression to field trials marks not only a technical achievement but also validates the collaborative approach between DRDO research establishments and industry partners in delivering complex defence systems. As the validation process continues, the VHF-SR radar is positioned to become a cornerstone of India's air defence architecture, providing enhanced surveillance capabilities and contributing significantly to national security objectives. The program's success establishes important precedents for future indigenous defence technology development and demonstrates India's commitment to achieving self-reliance in critical defence technologies.

IDN (With Agency Inputs)