How do guided missles work?
In: Physics
They are computers with rocket engines.
Im not surr what exactly you want to know, do you know how space rockets work? Because thats the same thing. You burn some fuel and if you have no human pilot its done by some avionics system or board computer or whatever you name it.
Basically 3 ways:
1. The missile follows a path indicated by someone or something external that shows it where to go. Like a friend with a flashlight (torch) who shows the way.
2. The missile follows a path indicated by something internal that shows it where to go. Like carrying your own flashlight (torch).
3. A combination of 1 and 2, above.
That’s all there is. But let’s get into some detail, here.
In the case of #1, above, the person firing the missile “paints” the target either with a spot from a laser, or with a beam of radio energy. Otherwise, the person steers the missile directly. Much depends on the origin of the missile: from air, ground, or sea?
* Laser: person launching the missile points a laser beam at a target. Missile follows the spot of the laser and blows up when it gets there;
* Radio energy (usually radar). person launching the missile points a radar at the target. The missile follows the return signal (an echo) back to the target;
* Optical: person launching the missile aims an optical scope at the target, maintaining the target in the cross hairs of the scope. The missile (by a radio link back to the launcher) adjusts its path based on any changes to the position of the scope.
In the case of #2, above, all the things described by #1 are done INTERNALLY in the missile, itself.
In the case of #3, above, the person launching the missile starts the missile on its way, then turns over control to the missile, itself.
All missiles, regardless of design, have these main components – warhead, body, propellant, steering surfaces, and communications hardware/software.
Whichever “released” the missile, communicated it instructions to follow, usually coordinates, to which the missile follows.
The more sophisticated the method of communication, the more accurate the missile is; hence why there are so many…
Infrared, radar, laser, GPS, “timing” components, etc…
And along with missile control surfaces, help make this missile “guided”.
It depends on the rocket. Some the launching platform preprograms a course or destination coordinates, thats common for guided rocket artillery and large platforms like cruise missiles.
Some follow a laser from either the launching platform or a third party.
Some have on board passive sensors following emissions like heat or radio waves to track onto vehicles or enemy radar.
Some have on board active radar.
For those last couple they may be able to seek out a target on their own but often the launching platform designates a target and the missile is using its sensors to try and stay on that target rather than finding it’s own.
There are many different methods and types depending on the intended target and what technology was available at the time that particular weapon was designed.
A missile would be some kind of usually longer range projectile and payload with built in propulsion (rocket engine, jet engine).
A guided missile is a missile that can steer. Usually some form of on board sensor and guidance system that can adjust the flight of the missile towards their target. Some missiles are designed to steer towards some kind signature (visual, heat, radio) so it can home onto its target. Others can be programmed with a fix destination and has the ability to navigate there autonomously using inertial guidance or GPS meaning it can adjust for wind, air pressure, or perhaps even terrain.
How they work in detail is way beyond an ELI5 since there are many types.
Heat, wire, radar, or laser. Heat seekers have a very sensitive optical camera in them that locks onto a heat source and commands itself to fly into it. Wire guided missiles like the TOW or ADCAP torpedo receive commands over a thin wire that tells them when to turn or whete to go. Radar is the new favorite, as there are many firms of it. You can use another radar to steer in a missile, or the missile itself can have an active, or in the case of HARM missiles, a passive radar receiver that tells it where the target is. Lastly, laser missiles like the Hellfire have a laser tracker in the head and track to a point that is “painted” in laser light by the firing vehicle.
It depends on the guidance, but it’s just a closed-loop control circuit. The missile detects a target and tracks it, the airfoils or exhaust vanes are steered to change it’s trajectory, and if the trajectory is wrong, that is detected by the sensor and the controls are adjusted accordingly.
Air-to-air missiles are generally one of two types: infrared or radar homing. An infrared missile has a sensor at the tip that is sensitive to heat. When launched, it steers the missile so that the target remains in the sensors view. They generally use a proximity sensor of some type, which tells the warhead to detonate when the missile is within the optimal range.
The radar homing type works in a similar way (but doesn’t necessarily have to stay pointed at the target, they can fly upwards to gain altitude first). They’re either guided by messages from the plane that launched them, which is using it’s radar to track the target, or they have their own radar to do so. In reality, it’s often both.
They use the radar information to steer towards the target and detonate when they get close enough.
It’s a very complicated subject, there’s a lot more to it than this.
To give an example of a super simplistic way a radar guided missile could navigate, let’s walk through a hypothetical system.
In the guidance head of the missile, there are four identical radar antennae arranged in a square, and all four are emitting their radar pulses directly forward. When they receive the radar echo, they measure how far off center the target is.
If all four antenna determine that the signal is exactly the same distance from the center of their antenna, the target is directly in front of the missile. If the antenna in the upper right quadrant measures the echo closer to center than the others, that means that the missile is pointed towards the lower left of the target. The computer adjusts the fins on the missile to steer it up and to the left until the target is centered again.
Latest Answers