How do missiles find targets?

[seb brown]

If someone shoots a missile at a moving target, how does the missile follow the target? If for example a plane is shot at, how does the missile know where the plane is going to move to? Is it just some heat seeking thingy? If so, what if there isn't any heat? I can't understand why they don't miss all the time, or why it's not really easy to move out there way. I've just realised this question might make me look like a bit of a terrorist.... I promise i'm just an inquisitive student in bristol.

[Ewood27]

I think a broad understanding of the principles and accurate detailed knowledge sufficient to allow you to build a missile are two different things. I'm no expert, but I understand that some missiles are heat-seekers and some have radar. In each case they search for the strongest target within a fairly narrow cone and simply turn towards it. That will almost inevitably mean they end up chasing the target from behind, but the missiles are so fast and can manoeuvre so sharply that they can catch their target.
There are also predictor guns which, being ground units, can use much bigger and more sophisticated radar and computer equipment to "lead" the target accurately by aiming off ahead of it. Once the shot is fired, however, there is no in-flight guidance. I read somewhere that the Royal Navy has such a gun for ship defence which in trials put bullets into a six-inch shell in flight.

I hope that answers your question. If you need any more there are any number of organisations that could help - the IRA, Al Qaeda and the like!

[BadBob]

On military Aircraft they are normally kitted out with 2 defence systems, chaffs and flares. The chaffs deal with the radar type as they are some sort of magnetic metal stuff which confuses the radar and the flares give out a small but high heat source and heat seeking missiles are attracted to these. However you cant just go dumping out chaffs and flares you need to time it right.

[darth vader]

There are other types too. Some of the long distance ones are guided in by spies sat close to the target; the spy "trains" a scope on the target, the info is sent by radio back to the missile. The Milan system used by british troops until recently, used a remote control system whereby the (anti-tank) missile was launched, then the firer continues to train his scope on the tank - the missile is still attached to the launcher by a thin, very long cable which trails out behind it, the cable sends signals to alter course. Of course the really big buggers (which you see on News progs) are guided remotely by satellite linkup, and are guided right up to the point of contact hence the accuracy.

[seb brown]

Thanks for the answers everyone! In the event some hooligan decides to shoot a missile at me, i now know what to do. Merry Christmas!

[keithtoo]

Heat seeking missiles obviously target a heat source, be it engine exhaust of decoy flares etc, but there are also several other targeting mechanisms. For instance there are wire guided missiles such as the (now outdated) TOW missile, where a literal line of wire is spooled out - attached to the missile and the gun/shooter - and communicates back and forth via this spooled line. Its kinda like being able to correct the flight path of a bullet while it is still in flight. Pretty neat, especially when it was first developed. There are pre-programmed missiles, such as the older cruise missiles, that follow the terrain based on continuously updated realtime data feedback compared against the original inputs. Then there are satellite guided bombs, using GPS and satellite target location. And others that the DOD hasn't let me in on.

[keithtoo]

Then there are laser guided missiles that use a laser from a ground spotter communicated back to an overhead plane and down to the missile which can correct its attack in flight. Wherever the ground spotter points his laser, goes boom.

[darth vader]

hey keithtoo it's amazing how i managed to come up with the same responses as you but three days earlier, I wish i'd done it 3 days after then i wouldn't have had to repeat your response.................

[keithtoo]

"Darth, I am your father". Upon further reflection, I did notice your attempt to hone in on an answer in your previous post. Due to a lack of communication between your launch vehicle and your delivery mechanism, you missed the target by an unacceptable margin. My target impact analysis of your verbal sortie shows very little contact with the target and significant collateral damage scattered over a wide area. My attempt to actually engage the target you were aiming at, has resulted in target termination. Mission accomplished. As you were.

[darth vader]

yah boo sucks

[keithtoo]

Hey Darth, I'm from America, we speak English over here (at least those of us not from Mexico). You oughta try it.

[darth vader]

It's a quote from a comedy series called "the good life" when Tom isn't allowed to swear so comes out with the line "yah boo sucks to you". btw Darth Vader says to Luke Skywalker "I am your father Luke" so you got that quote wrong...

[darth vader]

...and you speak American English which is different. (certainly can't find "oughta" in the Oxford English Dictionary - oh no, there it is under "Yank mispronunciation")