Question
Which of the following statements with regard to stealth technology is/are correct?
1. Stealth objects have a very small radar cross-section and are coated with Radar Absorbing Material.
2. Stealth objects can be detected using specific frequencies.
3. Stealth objects are coated with metamaterials to increase the scattering of electromagnetic radiation.
Explanation
Stealth technology is designed to reduce the detectability of an object by enemy sensors, particularly radar. Its effectiveness depends on controlling how electromagnetic waves interact with the object’s surface.
Statement 1 — Correct: The primary aim of stealth technology is to reduce an object’s Radar Cross-Section (RCS), making it appear much smaller to radar. This is achieved through geometric shaping, which redirects radar waves away from the source, and Radar Absorbing Materials (RAM), which absorb part of the incoming electromagnetic energy.
Statement 2 — Correct: Stealth does not mean complete invisibility. Aircraft are generally designed to reduce detection by high-frequency radars used for targeting, while low-frequency VHF and UHF radars may still detect them. However, such radars generally have lower resolution, making precise targeting more difficult.
Statement 3 — Incorrect: Metamaterials are engineered structures with specialised electromagnetic properties. In stealth applications, they are intended to reduce radar scattering by absorbing or manipulating electromagnetic waves. Increasing radar scattering would make an object more detectable and therefore work against stealth.
Therefore, Statements 1 and 2 are correct.