The F-117 Stealth Fighter's Stealth Technology
November 5th 2006 06:39
Last night I had a dream about me asking my warfare-obsessed college buddy how stealth jets remained invisible. And as usual with dreams, I can’t remember what his answer was. So I decided to find out for myself.
A radar system works something like sonar. It sends out bursts of radio signals. When these signals bounce off objects, it return to the radar antenna, which calculates the time it took to get back. This is how it knows how far away the object is.
To ensure that your standard airplane is aerodynamic, the chassis is rounded. The round shape ensures that no matter where the signal hits, some of it get reflected back (but hey, I prefer to be detected when I fly thousands of feet above the ground in a piece of metal.)
Stealth jets, on the other hand, have other motives. Like bombing. And for this they need to be invisible to the enemy radar. This can be done in two ways. One is by shaping the airplane in such a way that it won’t reflect radar signals. The other way is to make the plane out of a material that absorbs the radar signals.
A stealth aircraft is made of flat surfaces and sharp edges. When the radar signals hit the aircraft, the signals get reflected into all sorts of weird angles – but nowhere near the angle from where the signal originally came from. The result: the plane appears to be a small bird (they’re in for a surprise.)
There is a small catch however. When the plane banks, there is a probability that one of the panels could directly reflect a radar signal back to the antenna. I’ll guess when this happen, the stealth jet can expect to have some heavy anti-air missiles locked onto them very soon.
A radar system works something like sonar. It sends out bursts of radio signals. When these signals bounce off objects, it return to the radar antenna, which calculates the time it took to get back. This is how it knows how far away the object is.
To ensure that your standard airplane is aerodynamic, the chassis is rounded. The round shape ensures that no matter where the signal hits, some of it get reflected back (but hey, I prefer to be detected when I fly thousands of feet above the ground in a piece of metal.)
Stealth jets, on the other hand, have other motives. Like bombing. And for this they need to be invisible to the enemy radar. This can be done in two ways. One is by shaping the airplane in such a way that it won’t reflect radar signals. The other way is to make the plane out of a material that absorbs the radar signals.
A stealth aircraft is made of flat surfaces and sharp edges. When the radar signals hit the aircraft, the signals get reflected into all sorts of weird angles – but nowhere near the angle from where the signal originally came from. The result: the plane appears to be a small bird (they’re in for a surprise.)
There is a small catch however. When the plane banks, there is a probability that one of the panels could directly reflect a radar signal back to the antenna. I’ll guess when this happen, the stealth jet can expect to have some heavy anti-air missiles locked onto them very soon.
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