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Homing In On Laser Weapons
Bloodmoon1 writes "I just came across this article at GlobalSecurity.org that gives a very good summary of the current status of solid-state lasers as weapons. It gives you a good idea of where the JSF Laser system is at and just how much time, effort, and money has went into this project. Also has some basic, but very sufficent, explanations of some of the science behind the technology."
The answer to your question is called AN/TPQ-36 and AN/TPQ-37 "Firefinder" target acquisition radars. We've had them for 20 years - the -36 is designed to track mortar shells and the -37 other types of artillery (though IIRC, the -37 has all the functionality of the -36).
They are very effective. They calculate the location of the firing tubes, and that information is passed to artillery units tasked to provide counterbattery fire (usually MLRS rocket artillery). This all happens very quickly - 30 seconds to a few minutes' time.
I know this because Tyler knows this.
Present systems not only have to aquire the target, catagorize the target, determine the best weapon to use in response. Then there's the same problem with the weapon you use to retaliate -- it also doesn't travel in a straight line so you must compensate not only for the threat's non-straight-line behaviour but also your own countering weapon's non-straight-line behaviour.
Is you use the LASER, the second half of the problem goes away!
BTW: Aegis solves the problem in a manner that is elegent or brute force, depending on your point of view. It uses an electronically steered RADAR to track incoming targets, shoot a gattling gun in the direction of the target, then tracks both the incoming target & the outgoing rounds, uses this data to modify the direction the guns are pointed. Elegent in the simplicity of its concept, brute force due to the fact it applies massive processing power to allow it to track an enormous number of targets.
"Glory is fleeting, but obscurity is forever." --Napoleon Bonaparte
I would like to know how such a weapon will acquire/track/target an incoming projectile. (That was not sarcasm; I really would like to know.) Mortar rounds generally travel in a high parabolic path - think of the St. Louis arch. Larger artillery shells - such as those fired from a battleship - follow a flatter trajectory. The targeting system would have to acquire a small incoming object, predict the path it will follow, and fire within a few seconds. That looks like a daunting task.
It's a solved problem. The Sea Wolf point defence system can shoot down 4.5-inch shells as well as supersonic missiles. Sea Wolf was first deployed in combat in 1982. Of course, you are likely to run out of missiles before they run out of cannon ammo, but maybe you can buy enough time to hit them with an Exocet.
Warships are expensive, so a lot of money has been spent on ways to protect them!
In principle, yes. In practice, no. If you were to put a very high quality coating of silver (for visible wavelength lasers) or gold (for IR lasers) on your missile, in principle you could reflect 95 to 98% of incident light. Special optical coatings can result in >99% reflectance, but only over narrow wavelength ranges.
In other words, if the enemy knows the wavelength at which your laser operates, he can reduce the effectiveness of your laser weapons. For ground based installations, this still isn't a big problem--you just need a laser that's an order of magnitude more powerful, and you can cook even the reflective coatings on the other guy's missiles. I've done research work involving lasers in both physical chemistry and medicine, and I've seen a number of purportedly highly-reflective optical elements get toasted by a powerful enough beam. Also, high-quality optical coatings usually aren't meant to handle the stresses (physical and thermal) experienced by your typical missile (ballistic or tactical).
~Idarubicin
This would be the first weapon mounted on aircraft/heavy machinery that the pilot/operator wouldn't have to worry about running out of ammo in combat! That's a pretty serious advantage, no matter what other shortcomings the weapon may have.
Assuming he has an infinite energy source on board too, of course. Otherwise firing the weapon will decrease range/endurance by increasing fuel consumption. Currently the opposite it true, because it reduces weight.
Okay, I'll bite. Where does E=mc^2 come into this? I've worked with lasers for a number of years, and I have yet to see any of my lasing medium converted directly to energy. Lasers operate by kicking atoms into an excited state (usually an excited electronic state) and then emitting light when excited atoms relax back to ground state.
For the record, small lasers don't require "gigawattage" to operate. I have a laser pointer that runs on one AA battery--I'll be giving a talk using it in a couple of hours. A laser designed for a weapons application would be larger. Still, I could assemble a carbon dioxide laser that could start fires from several hundred feet away and still be light enough to carry--and operate for a while on a moderately hefty battery back.
Granted, I couldn't destroy missiles with it, but the article discussses lasers that are mounted on aircraft or vehicles, or are part of fixed installations. You don't need a large power supply for even an extremely powerful laser if it only fires the very short pulses (microseconds or nanoseconds) that would be most useful for military purposes.
~Idarubicin
as a few others have posted in regards to the shipboard Aegis systems currently in use - basically a fast tracker and a gatling gun - here is the method used by the ABL.
Sensors detect a target (e.g. infra-red senssors pick up exhaust plumes or radar picks up missile)
Kilowatt class Active Ranger System laser acquires and tracks target.
Tracking data goes to the Tracker Illuminator Laser, which locks onto the missiles body and determines the best position to hit the missile.
A third laser the Beacon illuminator bounces light of the laser to determine atmospheric interference.
Interference data allows the optics to be altered to 'correct' the COIL's beam so it is properly focused when it arrives on target.
Then the COIL (Chemical Oxygen Iodine Laser) fires, and hopefully burns a hole in the target. Destroying it ouright, disabling it, or blowing its fuel tanks.
"A kilowatt is 3,600,000 joules, 10 kilowatts in respect is 36,000,000."
What are you talking about? A kilowatt is a measure of power, and a joule is a measure of energy. The two are not directly comparable without a time factor thrown in. Do you mean a kilowatt hour is 3,600,000 joules?
By your calculation, lightning is 280-2,800 kilowatts (0.3-2.8 megawatts). As we all know, lighting is more in the range of 1.21 gigawatts (humor intended, but general priniciple remains the same). It's not like lightning strikes last for an hour.
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"To put this in prespective, the adverage person uses 64,800,000 joules a month, or 18 kilowatts... So for every time they fire this baby, they are blowing 50-100 bucks....
They essentially are what cause the blackouts in California."
What the fuck are you talking about? This causes the blackouts in California, not some sergeant flipping the switch on $100 of electricity.
Kevin Fox
if you hit a mirror with a powerful enough beam of laser light, the small fraction of light that's absorbed (no such thing as an ideal reflector) will rapidly ablate the mirror coat, and then you're screwed. we have problems with this with our pulsed IR laser at work - we need solid polished aluminum mirrors with heatsinks on the back, ad that's for a 500mJ, 500ns pulse; they don't last that long, either. a 100KW IR laser will vaporize pretty much anything that's not *perfectly* reflective, i.e. anything we can build with current technology.
Facts do not cease to exist because they are ignored. - Aldous Huxley
Some missiles spin anyway. The Sidewinder missile was intentionally slightly unstable and spun so that it flew in a spiral. Its seeker had one degree of control, up-down relative to the center of the spiral. When the heat source it was looking at was near the center of the spiral, the spiral would narrow down towards the target. When the heat source was not near the center of the spiral, the spiral would broaden out in a cone until it reacquired the heat source. Fairly early in its development a filter was added so that it would ignore anything with the precise infrared signature of the sun.
A bit of Karma whoring here, wish I'd gotten online sooner so that people would see this much earlier:
TheHigh Energy Laser Systems Test Facility (so-called HELSTF). Let's see if Tom's webserver can survive this...This is the laser test facility for the army and navy at White Sands Missile Range. They've got the world's most powerful laser (MIRACL: Mid Infrared Advanced Chemical Laser) there.
Being developed for them, by Livermore by the same guys that are doing the National Ignition Facility is a solid state laser. It works.
Also at HELSTF, and the first functional laser weapon, is Tactical High Energy Laser (aka THEL, and I hate that URL, btw...)
Search TRW for more stuff on lasers as well as Lockmart and Boeing, of course.
Do you know why the road less traveled by is littered with the bones of the unwary?