Context: Recently, the Defence Research and Development Organisation (DRDO) announced that it has developed a photonic radar system. India will likely become the fourth country after the US, China and Israel to induct these radars after key trials in late 2025.
Relevance of the Topic: Prelims: Key facts related to Photonic Radar.
What is a Radar?
- Radar is short for Radio Detection and Ranging.
- Radar uses radio waves to determine the distance, velocity, and physical characteristics of objects around the device.
- A transmitter emits a radio frequency signal aimed at an object (E.g., a cloud) whose characteristics are to be ascertained.
- A part of the emitted signal is echoed by the object back to the device (reflected back), where a receiver tracks and analyses it to determine the features of the targeted object.
What is a Photonic Radar?
- Photonic Radar is a next-generation radar system that uses light-based (photonic) technology to generate, process and analyse radio-frequency (RF) signals.
- Conventional radars generate radio frequency (RF) signals using electronic components (like oscillators). However, such radars find it difficult to generate high-frequency signals beyond 40 GHz.
- Photonic radars use lasers and optical components (like optical fibres and modulators) to generate radio frequency (RF) signals and process signals using a technique called optical heterodyning. Photonic integrated circuits (PIC) used in the photonic radar can generate RF signals in the frequency range of 100 GHz to terahertz range, which is difficult to achieve using traditional electronic circuits.
The Photonic Radar System in India has been designed by the Electronics and Radar Development Establishment (LRDE), a DRDO lab known for creating advanced radars like Arudhra, Aslesha, and Uttam AESA.
Superiority of Photonic Radar over Conventional radars:
- High Detection Ability: Photonic radars can spot objects that conventional radars miss, including stealth aircraft, drones, and even incoming hypersonic missiles.
- Longer Range, Sharper Image and Lesser Noise:
- Photonic radars can generate high bandwidth signals (the higher the bandwidth, the greater the resolution).
- It has a higher signal-to-noise ratio (noise emanates from the heat generated by electronic components in conventional radar) leading to sharper detection of the ‘echo’ from the target.
- As a result, the radars have longer range and the ability to map targets in high-resolution 3D.
- Immune to Jamming: Photonic components are practically immune to electromagnetic jamming or electronic warfare tactics that often try to blind or confuse traditional radars. Additionally, Photonic radars are capable of frequency hopping- they keep changing their frequencies, which confuses the jammers.
- Light Weight: Photonic components do not have copper and are lighter. This enables the fitting of these small, lighter radar systems in satellites, swarms of drones and fighter jets.
Potential Applications of Photonic Radar:
- Military Applications:
- With its ultra-wide bandwidth, low signal noise, and high precision, the photonic radar may be able to spot threats early.
- The radar system can be integrated with India's existing air defence infrastructure- such as Akashteer command and control system. Can be deployed on various platforms- including fighter jets (Su-30 MKI, Rafale, Tejas); mobile ground units for the Indian Army.
- Medical Applications: Photonic radar could be used as a non-invasive way to monitor patient vital signs, such as breathing and heart rate. The device could fit onto a photonic chip that is small enough to incorporate into electronic devices like a smartphone.
- Space Missions: Can be integrated into small satellites for deep-space tracking.
- Weather monitoring, high-resolution atmospheric observations & coastal surveillance.
Associated Challenges:
- Gaining access to PICs: India lacks infrastructure to fabricate Photonic integrated circuits (PIC).
- Export Restrictions: In order for large-scale production of PICs, India will have to design the circuits and get them fabricated outside India. However, that is a humongous task given the export restrictions from the US; security risks in fabricating them from China.
- Material Constraints: Photonics utilise special materials, mainly indium phosphide and silicon photonics, which are hard to procure. Similarly, other components like tunable lasers and modulators are hard to procure.
DRDO is preparing for extensive trials of the Radar in late 2025 to assess its effectiveness in diverse and challenging conditions. The technology strengthens India’s position in regional military balance and makes its defence systems much harder to bypass or fool.
New Emerging Radar Systems:
Two radar systems under development promise to be better than photonic radars.
Quantum Radar:
- Quantum radar uses quantum technology for detection and imaging. The technology is still in the experimental stage.
- At the core of this technology is the production of a pair of entangled photons- sending one photon to the target, and then comparing it on reflection with the second photon; the difference will be used to analyse the location and characteristics of the target.
Terahertz Radar:
- Terahertz radar operates in the electromagnetic spectrum between microwaves and infrared light (typically 0.1-10 THz) - where the signal oscillates a trillion times a second. The corresponding wavelength is about 0.3 mm. This will offer high resolution imaging.
Also Read: What is Synthetic Aperture Radar?