Escaping radar

The research in military weaponry never stops, even after the longest peace that humanity has ever known, the post World War 2. It seems that the old saying from General Vegetius, “If you want peace, prepare for war,” will never lose its relevance to humanity. And in today’s warfare, military technology has advanced so far it almost makes science fiction reality.

Detecting Enemy

Here, we are going to discuss how stealth aircraft earns its name. Old warplanes were noisy and detectable by radars. Once the enemy spotted an air-convoy, the anti-aircraft guns on the ground would prepare themselves to wipe the planes. But now, stealth technology has allowed military airplanes to be invisible from the radars. The technology behind it is very fascinating.

Getting to know radar system

An airplane radar works by sending radio wave to a specific area and receive its returning signals. The returning signals will give information on what object are there in the area. Large, solid, and objects moving slower than the radio wave speed are vividly visible with radars. And that is why the military has used the same technology in submarines and naval navigation. Radio locating used to be a terrifying reconnaissance method for an invading convoy.

Avoiding Radar with shape

Naval DetectorBecause radar reading depends on the reflection of the radio wave it has sent, once the shape of the hit object does not reflect back the wave, the object will not appear on radars. This phenomenon explains why stealth airplanes have a peculiar design, like the B-2 and F-117. If we compare them to commercial planes, we can easily infer that round shapes are the ideal design to be detectable by radars, and thus the military version is designed differently. They are thinner and more angular than commercial planes.

Anti-radar materials

The other way to escape radar detection is by using material that absorbs radio wave. Elements that belong to the category of radiation-absorbent (RAM) are the ones used on stealth planes, such as carbonyl iron, foam absorber, Jaumann absorber, and carbon nanotube.

Avoiding DetectionAnti-radar materials disrupt radio wave. It does not conceal the plane entirely but distorts the reflected signals. As a result, the reflected signals might be on the same length as the ones reflected by birds or cloud particles. The aim is to trick the radar operator into dismissing the signals.

Modifying the vertical tail

A stealth aircraft has to be thin to avoid radar. But aircraft tail serves as the stabilizer. As a result, the stabilizer needs to be modified to be as flat as possible. Stealth planes also utilize sophisticated computation to navigate the stabilizers.