LASER

A laser is a device that emits light (electromagnetic radiation) through a process called stimulated emission. The term laser is an acronym for light amplification by stimulated emission of radiation.[1][2] Laser light is usually spatially coherent, which means that the light either is emitted in a narrow, low-divergence beam, or can be converted into one with the help of optical components such as lenses. Typically, lasers are thought of as emitting light with a narrow wavelength spectrum ("monochromatic" light). This is not true of all lasers, however: some emit light with a broad spectrum, while others emit light at multiple distinct wavelengths simultaneously. The coherence of typical laser emission is distinctive. Most other light sources emit incoherent light, which has a phase that varies randomly with time and position.

Terminology

From left to right: gamma rays, X-rays, ultraviolet rays, visible spectrum, infrared, microwaves, radio waves.

The word laser originated as an acronym for light amplification by stimulated emission of radiation. The word light in this phrase is used in the broader sense, referring to electromagnetic radiation of any frequency, not just that in the visible spectrum. Hence there are infrared lasers, ultraviolet lasers, X-ray lasers, etc. Because the microwave equivalent of the laser, the maser, was developed first, devices that emit microwave and radio frequencies are usually called masers. In early literature, particularly from researchers at Bell Telephone Laboratories, the laser was often called the optical maser. This usage has since become uncommon, and as of 1998 even Bell Labs uses the term laser.[3]

The back-formed verb to lase means "to produce laser light" or "to apply laser light to."[4] The word "laser" is sometimes used to describe other non-light technologies. For example, a source of atoms in a coherent state is called an "atom laser."

DESIGN

Main article: Laser construction

A laser consists of a gain medium inside a highly reflective optical cavity, as well as a means to supply energy to the gain medium. The gain medium is a material with properties that allow it to amplify light by stimulated emission. In its simplest form, a cavity consists of two mirrors arranged such that light bounces back and forth, each time

passing through the gain medium. Typically one of the two mirrors, the output coupler, is partially transparent. The output laser beam is emitted through this mirror.

Light of a specific wavelength that passes through the gain medium is amplified (increases in power); the surrounding mirrors ensure that most of the light makes many passes through the gain medium, being amplified repeatedly. Part of the light that is between the mirrors (that is, within the cavity) passes through the partially transparent mirror and escapes as a beam of light.

The process of supplying the energy required for the amplification is called pumping. The energy is typically supplied as an electrical current or as light at a different wavelength. Such light may be provided by a flash   lamp or perhaps another laser. Most practical lasers contain additional elements that affect properties such as the wavelength of the emitted light and the shape of the beam.

LASER GUIDED MISSILE

BackgroundMissiles differ from rockets by virtue of a guidance system that steers them towards a pre-selected target. Unguided, or free-flight, rockets proved to be useful yet frequently inaccurate weapons when fired from aircraft during the World War II. This inaccuracy, often resulting in the need to fire many rockets to hit a single target, led to the search for a means to guide the rocket towards its target. The concurrent explosion of radio-wave technology (such as radar and radio detection devices) provided the first solution to this problem. Several warring nations, including the United States, Germany and Great Britain, mated existing rocket technology with new radio- or radar-based guidance systems to create the world's first guided missiles. Although these missiles were not deployed in large enough numbers to radically divert the course of the World War II, the successes that were recorded with them pointed out techniques that would change the course of future wars. Thus dawned the era of high-technology warfare, an era that would quickly demonstrate its problems as well as its promise.

The problems centered on the unreliability of the new radio-wave technologies. The missiles were not able to hone in on targets smaller than factories, bridges, or warships. Circuits often proved fickle and would not function at all under adverse weather conditions. Another flaw emerged as jamming technologies flourished in response to the success of radar. Enemy jamming stations found it increasingly easy to intercept the radio or radar transmissions from launching aircraft, thereby allowing these stations to send conflicting signals on the same frequency, jamming or "confusing" the missile. Battlefield applications for guided missiles, especially those that envisioned attacks on smaller targets, required a more reliable guidance method that was less vulnerable to jamming. Fortunately, this method became available as a result of an independent research effort into the effects of light amplification.

Dr. Theodore Maiman built the first laser (Light Amplification by Stimulated Emission of Radiation) at Hughes Research Laboratories in 1960. The military realized the potential applications for lasers almost as soon as their first beams cut through the air. Laser guided projectiles underwent their baptism of fire in the extended series of air raids that highlighted the American effort in the Vietnam War. The accuracy of these weapons earned them the well-known sobriquet of "smart weapons." But even this new generation of advanced weaponry could not bring victory to U.S. forces in this bitter and costly war. However, the combination of experience gained in Vietnam, refinements in laser technology, and similar advances in electronics and computers, led to more sophisticated and deadly laser guided missiles. They finally received widespread use in Operation Desert Storm, where their accuracy and reliability played a crucial role in the decisive defeat of Iraq's military forces. Thus, the laser guided missile has established itself as a key component in today's high-tech military technology.

HISTORY

Laser-guided missiles were first developed during the Vietnam War. The Army began to research laser guidance systems in 1962. The first laser-guided bomb, the BOLT-117, was developed by the Air Force in 1967; however, it was not used in combat until 1968. The BOLT-117 worked using two planes. One plane was used to keep a laser illuminating the intended target, while the other’s job was to drop the missile by following the reflected laser bean and directing the missile by sending signals to its control fins. For high efficiency, there was a very narrow region within which the pilot could release the missile. Laser-guided missiles of this time were generally made of standard iron and were simply dumb bombs with a laser guidance and control system attached. They commonly had a range of three to four kilometers

Guided weapons were nothing new to the  United States military, even in 1965.  The concept dated back to the Germans and World War II.  German scientists developed the FRITX-X and the HS-293 both based on radio controlled guidance.  These were used by the German Luftwaffe to destroy  the Italian battleship Roma on September 3, 1943 because the Italians were going to turn the ship over to the Allies.  At the end of  World War II, the U.S. Army Air Force had used radio guided bombs to destroy bridges in Burma, and then again five years later in Korea.  The weapons were difficult to use, hard to maintain and because of  radio control problems often were unreliable, but they

proved guided weapons were a reality.    However, the strategic thinking of the 1950s revolved around bombs large enough to destroy cities, not bridges.  The Pentagon promptly abandoned guided weapon development,. promising as it was, for a larger concept, that of nuclear weapons.  For the most part, during the 1950s, guided air-to-ground weapons were a neglected step child.  The favored approach was to use a blunt sledgehammer type nuclear weapon and not a surgical scalpel to take out targets.    The U.S. Navy and Air Force had been using radio guided weapons for a few years by the time the air war began over Southeast Asia.  However, the  bombs had unreliable guidance packages, and when they did hit a target the small warheads were not enough to destroy an object as large and well made as a bridge.  In the case of the 1965 Than Hoa raid, pilots reported the bombs simply bounced off the bridge with no noticeable damage to the French made structure.   Word started thinking along lines that would get American bombs closer to their intended targets.  An engineer with Texas Instruments, Word had been working on a submarine detection net off the New England coast and was looking for more challenging work  when he crossed paths with laser engineer Dave Salonimer, in late 1964. 

Salonimer was trying to convince the U.S. Army to use a laser targeting system for artillery strikes.  "Dave had conceived this idea of the Army artillery using a laser.  Well, Salonimer thought wouldn't it be great if you could take a flashlight, ala a laser, mark a target, and then send a missile or a shell or whatever over the hill and hit it," Word said.  "Those where the

serious early thoughts about laser guidance."   Within the military, however, there were no takers for Salonimer's "Buck Rogers" idea of using lasers to guide projectiles, and in late 1964 the Huntsville, Alabama based scientist  wanted Texas Instruments to devise a way to launch a Shrike air launched anti-radar missile from the ground then use a laser guidance system to guided the missile to a marked target.  It all sounds easy, today, for the buddy lasing tactic is standard work for the U.S. Army and Air Force, but in 1964 it was still the stuff of science fiction.   Adapting an air launched missile for ground use wasn't easy either, remembers TI engineer Tom Weaver. "We started looking at the use of the Shrike airframe, which is not very good I might add, but it was low

cost and simple to make," Weaver said.  "It looked promising, enough for a demo contract anyway, but nothing came of it."

The Army passed on the idea of a laser guided Shrike, but the idea of using a laser didn't die with the theoretical laser guided Shrike missile.  A few engineers at Texas Instruments saw laser guidance as a viable, low cost and ultimately light weight approach to guiding a bomb or maybe an artillery shell.       Laser light is able to project a spot over great distances and the beam of light stays tight.  Unlike a flashlight beam shined into the trees on a dark night. the laser beam doesn't scatter light particles. Because the beam stayed tight, Word felt he could use it as information to guide a weapon. Just after working on the Shrike study,  While working on TI systems at Eglin Air Force Base, Florida, Word discussed the issue of bomb accuracy with U.S. Air Force Colonel Joe Davis who as the deputy base commander was in charge of weapons ranges at Eglin.   "Joe wanted to find a way to help our guys over in Southeast Asia get their bombs right on the target. Now, he wasn't in the bomb development business, but Joe knew there was a problem, and he wanted to find and answer," Word said.    Blazing through heavy ground fire and flak was normal for most bomb runs throughout Southeast Asia.   Many World War II veterans who flew in the war remembered the flak being more intense in some spots of  North Vietnam than it had been in heavily defended sections of Germany two decades earlier. Since most aircrews didn't want to end up with jets shattered by exploding anti aircraft fire, they jinked to avoid it, thus spoiling the aim of their bombs.   Pulling out a picture of the Than Hoa Bridge out of a desk drawer, the Eglin colonel showed Word where the problem was, Word remembers. "I started counting craters in that photo. I stopped when I got to 800 or so, and I never did finish." Davis told Word he wanted a weapon that could be released around 10,000 feet and then "fly" the rest of the way to the target with a large enough warhead that one or two bombs would destroy even the hardiest of targets.  Giving the issue some thought, Word and other engineers at TI figured  a beam of laser light could be used as a bomb guidance system.  The Shrike studies had been promising, but when the TI engineers broached the idea with anybody at Eglin but Colonel Davis it was as if a Hollywood producer had walked into the room wanting to make a teleplay out of the latest science fiction novel.  "They would just laugh at us and think we were nuts," Word recalled. There were those within TI who thought lasers

were a far fetched dream, too. "Many people just thought it was crazy.  There were a lot of detractors -- military and within TI -- who said this can't be done," TI engineer Nick Baker said.    A few months after seeing the photo of the Than Hoa Bridge, Word had almost given up on using a laser guidance system when Davis stoked again the fires of development.  "On a Friday morning in early June of '65, we mentioned to Joe Davis that no one else at Eglin feels the Air Force  has a bombing problem," Word recalls.   "Col. Joe explodes. Then he says, 'Have a proposal on my desk by 8 a.m. Monday and I will fund it.  It has to be for a dozen guided bombs that have a thirty foot delivery accuracy and, of by the way, it needs to be fixed price for less than $100,000 and the schedule has to be six months for delivery and flight test.' "   Over that weekend the Word embarked on a marathon, sleepless 72-hour development session.  By Monday, the end result was an 18-page hand written proposal for a laser guided bomb development program which he felt could deliver a bomb that could come within thirty feet of a target; the program was projected to cost $99,000, with a six month delivery schedule.   "Later it turned out to be nothing like what we produced. I mean we just had a seeker device basically nailed onto a stabilizer. There was no way it would have flown," Word said. "It was just a bunch of junk, but that's where we laid the ground work was in that original proposal."    Word made the deadline, and while he waited on the Eglin military and civilian officials to butt heads over his proposal, the Texas Instruments engineer grabbed a six pack of beer and headed to the nearest beach. "We were told to get lost for a few hours, so I headed to the beach," he said. On paper, the concept was convincing to Colonel Joe Davis who sent the proposal straight to Wright-Patterson Air Force Base, Ohio, home of Air Force research and development projects. Within a few days, the idea made its way to the Limited Warfare Office at Wright Patterson and landed on director Jack Short's desk.  The office had a program where defense contractors could come up with ideas for improved weapons or war material such as better tent pegs, ponchos or radio equipment.  A good idea would net a company $100,000 in seed, or development, money and if it worked maybe a lucrative government contract to build the product.    After a severe lobbying campaign from Davis and Word, the office signed off on the project, giving the TI team $100,000 in development funds.  The team had six months to develop a device which for the military would change the way bombing accuracy was defined. Their task was to get the bomb within 30 feet of the target.   This would beat the average bomb accuracy of the day, which ranged from 100-1,000 feet depending on the tactics, the target and the weather.   "I don't think we knew what we were building at first -- not in terms of the scope of the program. Certainly, we didn't envision this would

become what it has today in terms of accuracy and reliability, " Nick Baker offered. "We just wanted to find a way to guide a bomb. Nobody really thought it would be as accurate as it was."  

    A lthough the bomb may appear simple in design today -- bolt a guidance seeker on the front and control fins on the rear of  a standard bomb casing -- in the fall of 1965 it was anything but easy. Word and his fellow engineers identified the problems they would have to conquer in a short time.  First, the team had to develop and build a seeker which would sense the laser light, and then figure a way to move that information to the Shrike control unit bolted on the end of the bomb.  Finally, they had to make it fly -- the bomb had to be aerodynamic.   "It was unlike any other development program anyone had ever seen," Word says today. "We had so little time and there was a heck of

a lot of improvising.  One problem would crop up, we would solve it, and then another three would be waiting.  You had to move fast."   Most of the work was adapting and improving missile technology, but Tom Weaver remembered one of the most significant challenges the TI team faced was electronically moving the guidance data from the seeker to the control unit in an era of  transistors and circuit breadboards.  "We faced the problem that this had never been tried before.  It wasn't so much (developing) the laser, as it was working with that slow data rate we had to guide on.  It was only like eight or ten pulses per second.  And as far as data rates go that's very slow when you are talking about a bomb falling through the

air to a target some 6,000 to 8,000 feet away," Weaver said. "That data rate problem was one of the biggest challenges to get past."  The team finally locked in 10 pulses per second as the golden number for a bomb to guide to the target.     Working out of TI's labs in Dallas, Texas, and trudging down to the steamy, jungle like ranges of Eglin Air Force Base, Florida, the team set about to make laser guided bombs a reality in September 1965.  With only six months to design, test and prove laser guidance, the pressure of the ticking clock brought on a fast paced, sometimes unorthodox development cycle for the guided bomb. The TI engineers didn't know how to use a laser, having never seen a working model. Salonimer

loaned them a laser, one of only two in the world, and they used the water tower in Plano, Texas as a fixed object to measure laser light return. Although certainly not a new  discovery to science by 1965, the laser was virgin territory for the TI engineers.  At first, they didn't  know how to read if the machine was on or off. It was a simple problem with a simple solution, Word remembers.  "We got this thing and we were out on the outskirts of  Dallas on about a three story building.  We were shooting the laser at a Plano, Texas water tower about a mile away.  That was the only thing sticking out of the ground. We didn't know anything about safety.  We didn't know enough about lasers at all.  We were using wet emulsion Polaroid film.  The only way we could tell the laser worked was to take the Polaroid film, hold it with your finger tips and stick it front of the laser.  We knew it was on and working if it blew a hole through the film about the size of a penny right through the film," Word recalls.   The laser may have presented a unique set of detection problems, but at least it was a tangible device.  The seeker was designed and built from a concept which had been drawn out on a sheet of paper.  There was no such device.  A challenge, the seeker was the part of the system the team had to develop on their own.    The engineers figured out that a silicon material could be used to detect the light, they fashioned a thin wafer of the silicon and placed it in the front of the seeker. The material detected the laser light. The next challenge was the aerodynamics of the sensor.  After running through a few mathematical analog computer simulations on machines that required programming in terms of turning gears and cogs, TI aeronautical engineer Dick Johnson struck upon the idea to use an aircraft probe. Johnson thought that a probe device, which is used to measure air flow around leading edges of aircraft, would work aerodynamically as a seeker.   "We struck on the idea of lets put the seeker in a Geanini Probe," Word said. "What that will do is put the seeker, the instrument that is looking for the spot the instrument that is giving guidance directions." The probe resembled a badminton birdie, and from then on it was dubbed the "Birdie Head."   The engineers couldn't just slap the probe on the end of the bomb, and brand it a guided weapon, though.  It had to be aerodynamic.  There was no funding to test the aerodynamics of the laser guided bomb shapes in a wind tunnel.  A back yard swimming pool held the answer. Johnson made several scale models of the fat shaped World War II bombs and used a swimming pool to test their aerodynamic wind flow.   "About a month into this, Dick came in with a little model he had made at home.  It was about 10-inches long.  We took that model, went out to the swimming pool and dropped it.  He had different size control surfaces and he was trying to get the dart to have stability with the smallest size fins we could make.  We had to get it under the wing of

the airplane, and if you couldn't get it going outwards you had to go radially," Word recalls.   The lack of  money in late 1965 also meant the team had to be creative in the test approach used at Eglin Air Force Base,

Florida.  With no funds for large data collection devices and expensive machinery, the key word in the test program was "improvise," Nick Baker recalls.   "When we did the first tests, well, we didn't have enough money to go put a nice telemetry system on the weapon.  We had a high resistance tape recorder that you just screwed in the fuse well.  That bomb would go down and burrow down and it may go off to the side, and we had to find it to recover this tape recorder.  It looked like we were digging up half the county down there to find the things.  You had great big cranes out there digging up all these holes to recover that data.  You normally think of test programs with big telemetry systems, and we did not have a wealth of data.  If you had to stand out there for a week digging, then it was worthwhile to do that.  You just had to have that information.  No matter what the result was that created the hole in the ground, you had to have the information to judge the performance of it."   Digging in the sand and clay of west Florida was worth the trouble to the TI team.  Out of ten bombs tested on the Florida ranges, eight were deemed a success, coming within thirty feet or closer to the target.   The Air Force began combat trials of the bombs in 1968, and based on those, the Paveway was redesigned and mated in the summer to the "slick" shaped or (for an explanation of aerodynamic shaped bomb click here) Mark-80 series of bombs.

Raw MaterialsA laser guided missile consists of four important components, each of which contains different raw materials. These four components are the missile body, the guidance system(also called the laser and electronics suite), the propellant, and the warhead. The missile body is made from steel alloys or high-strength aluminum alloys that are often coated with chromium along the cavity of the body in order to protect against the excessive pressures and heat that accompany a missile launch. The guidance system contains various types of materials—some basic, others high-tech—that are designed to give maximum guidance capabilities. These materials include a photo detecting sensor and optical filters, with which the missile can interpret laser wavelengths sent from a parent aircraft. The photo detecting sensor's most important part is its sensing dome, which can be made of glass, quartz, and/or silicon. A missile's electronics suite can contain gallium-arsenide semiconductors, but some suites still rely exclusively on copper or silver wiring. Guided missiles use nitrogen-based solid propellants as their fuel source. Certain additives (such as graphite or nitroglycerine) can be included to alter the performance of the propellant. The missile's warhead can contain highly explosive nitrogen-based mixtures, fuel-air explosives (FAE), or phosphorous compounds. The warhead is typically encased in steel, but aluminum alloys are sometimes used as a substitute.

DesignTwo basic types of laser guided missiles exist on the modern battlefield. The first type "reads" the laser light emitted from the launching aircraft/helicopter. The missile's electronic suite issues commands to the fins (called control surfaces) on its body in an

effort to keep it on course with the laser beam. This type of missile is called a beam rider as it tends to ride the laser beam towards its target.

The second type of missile uses on-board sensors to pick up laser light reflected from the target. The aircraft/helicopter pilot selects a target, hits the target with a laser beam shot from a target designator, and then launches the missile. The missile's sensor measures the error between its flight path and the path of the reflected light. Correction messages are then passed on to the missile's control surfaces via the electronics suite, steering the missile onto its target.

Regardless of type, the missile designer must run computer simulations as the first step of the design process. These simulations assist the designer in choosing the proper laser type, body length, nozzle configurations, cavity size, warhead type, propellant mass, and control surfaces. The designer then puts together a package containing all relevant engineering calculations, including those generated by computer simulations. The electronics suite is then designed around the capabilities of the laser and control surfaces. Drawings and schematics of all components can now be completed; CAD/CAM

(Computer-Aided Design/Manufacture) technology has proven helpful with this task. Electronics systems are then designed around the capabilities of the aircraft's laser and the missile's control surfaces. The following step consists of generating the necessary schematic drawings for the chosen electronics system. Another computer-assisted study of the total guided missile system constitutes the final step of the design process.

The Manufacturing Process

Constructing the body and attaching the fins 1 The steel or aluminum body is die cast in halves. Die casting involves pouring

molten metal into a steel die of the desired shape and letting the metal harden. As it cools, the metal assumes the same shape as the die. At this time, an optional chromium coating can be applied to the interior surfaces of the halves that correspond to a completed missile's cavity. The halves are then welded together, and nozzles are added at the tail end of the body after it has been welded.

2 Moveable fins are now added at predetermined points along the missile body. The fins can be attached to mechanical joints that are then welded to the outside of the body, or they can be inserted into recesses purposely milled into the body.

Casting the propellant 3 The propellant must be carefully applied to the missile cavity in order to ensure

a uniform coating, as any irregularities will result in an unreliable burning rate, which in turn detracts from the performance of the missile. The best means of achieving a uniform coating is to apply the propellant by using centrifugal force. This application, called casting, is done in an industrial centrifuge that is well-shielded and situated in an isolated location as a precaution against fire or explosion.

Assembling the guidance system 4 The principal laser components—the photo detecting sensor and optical filters

—are assembled in a series of operations that are separate from the rest of the missile's construction. Circuits that support the laser system are then soldered onto pre-printed boards; extra attention is given to optical materials at this time to protect them from excessive heat, as this can alter the wavelength of light that the missile will be able to detect. The assembled laser subsystem is now set aside pending final assembly. The circuit boards for the electronics suite are also assembled independently from the rest of the missile. If called for by the design, microchips are added to the boards at this time.

5 The guidance system (laser components plus the electronics suite) can now be integrated by linking the requisite circuit boards and inserting the entire assembly into the missile body through an access panel. The missile's control surfaces are then linked with the guidance system by a series of relay wires, also entered into the missile body via access panels. The photo detecting sensor and its housing, however, are added at this point only for beam riding missiles, in which case the housing is carefully bolted to the exterior diameter of the missile near its rear, facing backward to interpret the laser signals from the parent aircraft.

Final assembly 6 Insertion of the warhead constitutes the final assembly phase of guided missile

construction. Great care must be exercised during this process, as mistakes can lead to catastrophic accidents. Simple fastening techniques such as bolting or riveting serve to attach the warhead without risking safety hazards. For guidance systems that home-in on reflected laser light, the photo detecting sensor (in its housing) is bolted into place at the tip of the warhead. On completion of this final phase of assembly, the manufacturer has successfully constructed on of the most complicated, sophisticated, and potentially dangerous pieces of hardware in use today.

Quality ControlEach important component is subjected to rigorous quality control tests prior to assembly. First, the propellant must pass a test in which examiners ignite a sample of the propellant under conditions simulating the flight of a missile. The next test is a wind tunnel exercise involving a model of the missile body. This test evaluates the air flow around the missile

during its flight. Additionally, a few missiles set aside for test purposes are fired to test flight characteristics. Further work involves putting the electronics suite through a series of tests to determine the speed and accuracy with which commands get passed along to the missile's control surfaces. Then the laser components are tested for reliability, and a test beam is fired to allow examiners to record the photo detecting sensor's ability to "read" the proper wavelength. Finally, a set number of completed guided missiles are test fired from aircraft or helicopters on ranges studded with practice targets.

USAGES(LAND BASE MISSILE)

You will need: Wiremod and something heavy and preferably metal as it will be running into stuff alot, depending on how bad of a steerer you are.

1. Spawn the base object. I used a barrel, but anything can do. Be sure to freeze it, as the rocket tends to take off if you wire things up in the wrong order. Nothing worse than a Wile E. Coyote impression.

2. Attach a GPS and a laser reciever. 3. attach a Wired Numpad, we will use 1 to turn the thruster on and off. (you really

can use any number but zero, because the vector thruster multiplies the input number by what you set as the force multiplier)

4. attach three arithmatic chips set to 'subtract'. try to place them in such a way so as to make it easy to keep track of which chip is the x variable, which is the y, and which is the z. This can get confusing, and can go very wrong very fast, such as sending the missle flying into the ground, or you.

5. Set each arithmatic chip with B to the respective laser reciever coord (x,y,orz) and A to the respective GPS coord. Be sure that you have the B to the reciever and the A to the GPS and not vice-versa or you will have a laser repelled missile Another useful tip is to go from the chip to the module, or you will not be able to attach to the coord variables. This frustrated the author until he figured this out.

6. Set the numpad to be off. It will display a number on its popup if it is on. You want it off for now.

7. Attach a vector thruster with the coordiate system set to xyz world. Setting the system to local will result in a rocket worthy of Wile E. Coyote himself. Also set the Force multiplier to your desired thrust, which is what it will be if you use "1" for the numpad. Check "toggle"

8. Wire the thruster in this order: 1. Mul wired to the numpad output "1" 2. X to the arithmatic chip for x-coords 3. Y to the chip for y 4. Z to the chip for z

9. Using the laser pointer from the scripted weapons, register it to the laser pointer reciever using the secondary fire mode.

10. unfreeze the base object and flip on the numpad toggle (1 if you followed my plans). If you wired everything right the missile should follow wherever you point the laser pointer.

Using the Missile

Turning the beam off will have the missile hold position at the location you last targeted it to. This makes it an ideal trap weapon, as occasionally someone will come up and investigate the odd jet propelled barrel flailing on the ground or against a wall, only to have it suddenlly and surprisingly accurately flying at their head.

Make it better: Welding an explosive barrel to the main object creates a war head, without

destroying the body of the missile(in theory, never had it happen but...) Just watch out for walls and pointing too close to yourself(much like the rocket launcher in half-life, only much more leathal.)

This same (relatively) simple setup can be adapted to many devices, and the simplicity of steering in three dimentions with this setup makes it perfect for zero gee battles

Try putting wire explosives on the missile and watch them obliterate the target as the missle impacts.

Making the model an AMRAM missile is more realistic and more fun to play with. Its abit harder to control than the barrel so put a vector thruster at the top and bottom and wire them accordingly.

USAGES (AIR BASE MISSILE)

The basic operational concept for laser guidance and targeting from a combat aircraft was simple.   The Weapons System Operator would use a laser marking device mounted on the back-seat canopy of one F-4 to illuminate that target.  Another F-4 loaded with the laser guided bombs would make the attack dive bomb run.  Depending on fuel loads, the Phantom could carry two 2,000 pound guided bombs.   The number was fewer because the fixed guidance fins on the bomb only allowed one bomb per station on the fighter.  In later versions of the Paveway bomb, folding rear fins allowed for two bombs to be loaded on aircraft bomb station hardpoints.Later in the Vietnam War fighters used pods and could designate their own targets or a target for a flight of F-4s, but even the buddy system, which put two aircraft at risk instead of one, was deemed so accurate by the Air Force it

went into combat trials and was later dubbed the Pave Light system (PAVE is an acronym for Precision Avionics Vectoring Equipment) when the back-seat illumination routine was used in combat.  Later, Pave Knife pods, the primitive precursor to current day targeting pods, were carried by a single F-4 in a two or four ship flight.  The pods allowed one aircrew to illuminate a target and several to drop their guided bombs on it.    This was a particularly useful tactic for well protected, sturdy bridges.  By summer 1973, just before airstrike operations from bases in Thailand were canceled, F-4s were equipped with the more advanced Pave Spike pod which featured a television-laser combination tracking and targeting system, a bomb release computer and an easy access cockpit mounted control panel.  The pod, which resembled a long tube with a big bulging bulb on the forward end, was mounted on one of the Phantom's centerline Sparrow missile wells.  This freed up a wing station for more ordnance.

  After initial test practice runs for aircrews, the bombs were easy to use, unlike the complicated optical glide bombs and missiles of the day.  More importantly to the Air Force, the bombs not only came within the thirty foot target designation, they were cheap. When compared to other "precision" guided weapons at the time, Paveway I was a frugal

investment.   The GBU-8 television guided bombs which had a higher failure rate, cost the government around $17,000, but the initial Paveway bombs were priced at around $4,000, Word remembers, and as the production lines geared up near the end of the Vietnam War the bomb prices had dropped to $2,000 a copy.   Compared to the pay stub of a young Air Force officer of the time, though, the bombs were deemed expensive, but the aircrews wouldn't have traded them for the bomb's weight in gold in combat.  "We used to say we were dropping a Cadillac," retired U.S. Air Force Lieutenant Colonel Dean Failor recalled. "They were very accurate, and I guess compared to other munitions of the time cheap, but to us 'Crew Dogs' they were Cadillacs.  They were worth a Cadillac too, because they worked.  We really didn't like the electo-optical guided bombs because they didn't always work." Failor was a WSO who used  laser guided bombs from 1970-1973 in tours of duty in Southeast Asia including the Linebacker I and II campaigns.  The bombs were used for more that just dropping bridges, Failor said. "They were very versatile. We used them for cutting road junctions along the (Ho Chi Mihn) Trail, hitting bulldozers, just about all hardened targets and even destroying tanks," Failor recalled. "I remember one bulldozer we hit that had been hidden in a bomb crater at a difficult angle (to

strike). We put the laser guided bomb right on it, and the dozer just started tumbling end over end."    Within Texas Instruments there was a lot of hoopla surrounding Paveway bombing accuracy, Tom Weaver thought. "A lot of people say those bombs were coming within seven to ten feet of the target. I don't think we ever got them that close, but we sure got them within the 30-foot range," Weaver said.  Although very accurate, Paveway bombs were not magic bullets. Launch parameters, which pilots call a "basket," had to be followed or the bombs would not guide.   The release parameters were  much the same as dive bombing -- roll in on the target around 20,000 feet, acquire the target and release the bomb at about 10,000 feet. The laser guidance allowed the pilots to pull out the desired 10,000 foot altitude mark, largely above the bulk of the deadly ground fire.   "You had to be good at what you were doing," Failor said. "There's no doubt about that.  There had to be cooperation between the guy in back and the pilot and a general understanding of how the bomb worked. Once you got that down, though, it went well.  When you used it properly the laser guided bomb was so much better than a regular iron bomb that there is just no comparison."   Drawbacks to the weapons usage were cloudy weather, and also haze and smoke from previous bomb runs could pose a problem.  The first Paveway systems had no night time capability.  Even with the drawbacks, though, the bombs racked up a  68-percent kill record.  By the end of the conflict in Vietnam, the Air Force had used more that 25,000 laser guided bomb units, and 17,000 had been judged successful..

Diagram of an aircraft approaching a target to be destroyed by a laser-guided missile.

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VARIOUS TYPES OF LCM(LASER CONTROL MISSILE)

The development of laser quidided weapons has dramatically improved the accuracy of weapon quidance and delivery. With the assistance of build-up guidance kits, general GP bombs are turned into laser-guided bombs (LGBs). The kits consist of a computer- control group (CCG), guidance canards attached to the front of the warhead to provide steering commands, and a wing assembly attached to the aft end to provide lift. LGBs are maneuverable, free-fall weapons requiring no electronic interconnect to the aircraft. They have an internal semiactive guidance system that detects laser energy and guides the weapon to a target illuminated by an external laser source. The designator can be located in the delivery aircraft, another aircraft, or a ground source. All LGB weapons have a CCG, a warhead (bomb body with fuze), and an airfoil group. The computer section transmits directional command signals to the appropriate pair(s) of canards. The guidance canards are attached to each quadrant of the control unit to change the flightpath of the weapon. The canard deflections are always full scale (referred to as "bang, bang" guidance). The LGB flightpath is divided into three phases: ballistic, transition, and terminal guidance. During the ballistic phase, the weapon continues on the unguided trajectory established by the flightpath of the delivery aircraft at the moment of release. In the ballistic phase, the delivery attitude takes on additional importance, since maneuverability of the UGB is related to the weapon velocity during terminal guidance. Therefore, airspeed lost during the ballistic phase equates to a proportional loss of maneuverability. The transition phase begins at acquisition. During the transition phase, the weapon attempts to align its velocity vector with the line-of-sight vector to the target. During terminal guidance, the UGB attempts to keep its velocity vector aligned with the instantaneous line-of- sight. At the instant alignment occurs, the reflected laser energy centers on the detector and commands the canards to a trail position, which causes the weapon to fly ballistically with gravity biasing towards the target.

Target designators are semi-active illuminators used to "tag" a target. Typical laser guided bomb receivers use an array of photodiodes to derive target position signals. These signals are translated into control surface movements to direct the weapon to the target. An airborne detector can provide steering information to the pilot, via his gunsight, for example, and lead him on a direct heading to the target, finally giving him an aim point for a conventional weapon. Alternatively, a laser guided "smart" bomb or missile may be launched when a pilot is satisfied that the detector head has achieved lock-on and the launch envelope requirements are satisfied. In either of these cases, the pilot may never see the actual target, only the aim point as indicated by the laser.

Laser designators and seekers use a pulse coding system to ensure that a specific seeker and designator combination work in harmony. By setting the same code in both the designator and the seeker, the seeker will track only the target designated by the designator. The pulse coding is based on Pulse Repetition Frequency (PRF). The designator and seeker pulse codes use a truncated decimal system. This system uses the numerical digits 1 through 8 and the codes are directly correlated to a specific PRF. Dependent upon the laser equipment, either a three digit or a four digit code can be set. Coding allows simultaneous or nearly simultaneous attacks on multiple targets by a single aircraft, or flights of aircraft, dropping laser guided weapons (LGWs) set on different codes. This tactic may be employed when several high priority targets need to be expeditiously attacked and can be designated simultaneously by the supported unit(s).

Fire control laser systems are laser rangefinders (LRFs) and laser designators (LDs). These laser systems can be far more harmful to the eye than laser training devices such as MILES and Air-to-Ground Engagement System/Air Defense (AGES/AD) laser

simulators. Consequently, fire control lasers require control measures to prevent permanent blindness to an unprotected individual viewing the laser system from within the laser beam.

PAVE PENNY (AN/AAS-35) : Laser tracker pod used on the A-10 and A-7 aircraft. Does not contain a laser.

PAVE SPECTRE (AN/AVQ-19): Laser tracking and designator used on C-130 gunships.

PAVE SPIKE (AN/AVQ-12) : Laser tracking and designator pod fitted on F-4 and F-111 aircraft.

PAVE TACK (AN/AVQ-26) : Advanced optronics pod containing stabilized turret with FLIR, laser designator and tracker used on the F-4, RF-4, and F-111F aircraft.

The following systems are not in the active inventory but are included for information PAVE ARROW (AN/AVQ-14): This was a laser tracker pod developed for use in

conjunction with the PAVE SPOT laser designator used on O-2A FAC spotter planes, C-123, and was planned for use on the F-100. It was eventually merged with the PAVE SWORD program.

PAVE BLIND BAT: The PAVE BLIND BAT consisted of a laser target designator to illuminate targets for the PAVE WAY guided bombs. The PAVE BLIND BAT had an effective range of 18,000 feet and was developed for use by AC-130 gunships to aid supporting fighter aircraft.

PAVE FIRE: Development of laser scanner to aid F-4 Phantoms in securing proper target bearing.

PAVE GAT: Development of a laser rangefinder for use on the B-52G. PAVE KNIFE (AN/ALQ-10): The original laser designator pod developed by

Aeronutronic-Ford and used in combat in Vietnam. PAVE LANCE: Developmental effort to replace the PAVE KNIFE by improving

night capability with the addition of a FLIR in place of the low light television (LLTV). Superseded by PAVE TACK.

PAVE LIGHT (AN/AVQ-9): Stabilized laser designator developed for the F-4 Phantom.

PAVE NAIL (AN/AVQ-13): Modification of 18 OV-10 FAC aircraft with stabilized periscopic night sight and laser designator. Program coordinated with PAVE PHANTOM and PAVE SPOT.

PAVE PHANTOM: Addition of an ARN-92 Loran and computer to the F-4D allowing aircraft to store targeting information for eight separate positions illuminated by OV-10 PAVE NAIL.

PAVE PRONTO: Modification of AC-130 gunships for night attack including an LLTV Electro systems night observation camera, AAD-4, or AAD-6 FLIR and AVQ-17 illuminator.

PAVE SCOPE: Target acquisition aids for jet fighter aircraft such as the Eagle Eye (LAD) AN/AVG-8, and TISEO.

PAVE SHIELD: Classified project undertaken by Aeronautical Research Associates.

PAVE SPOT (AN/AVQ-12): Stabilized periscopic night vision sight developed by Varo for use on the O-2A FAC. The system was fitted with a Korad laser designator (ND:YAG).

PAVE STRIKE: A related group of air-to-ground strike programs include PAVE TACK and IR guided bombs.

PAVE SWORD (AN/AVQ-11): Laser tracker designed to pick up energy from targets illuminated by O-2A spotter planes. Used on F-4, and bore sighted with its radar set.

LGBs are not a "cure all" for the full spectrum of targets and scenarios facing fighter/attack aircraft, but they do offer advantages in standoff and accuracy over other types of free fall weapons in the inventory. In a high threat environment, LGB will be employed in a range of missions from close air support [CAS] to interdiction.

LGB are excellent performers in dive deliveries initiated from medium altitude. A steep, fast dive attack increases LGB maneuvering potential and flight ability. Medium altitude attacks generally reduce target acquisition problems and more readily allow for target designation by either ground or airborne designation platforms. Medium altitude LGB dive delivery tactics are normally used in areas of low to medium threat.

LGBs can miss the target if the laser is turned on too early. During certain delivery profiles where the LGB sees laser energy as soon as it is released, it can turn from its delivery profile too soon and miss by falling short of the target. To prevent this, the laser designator must be turned on at the time that will preclude the bomb from turning down toward the target prematurely. Normally, the pilot knows the proper moment for laser on. The specific LGB and the delivery tactics of the fighter/attack aircraft dictates the minimum designation time required to guide the weapon to the intended target. The effects of smoke, dust, and debris can impair the use of laser-guided munitions. The reflective scattering of laser light by smoke particles may present false targets. Rain, snow, fog, and low clouds can prevent effective use of laser-guided munitions. Heavy precipitation can limit the use of laser designators by affecting line-of-sight. Snow on the ground can produce a negative effect on laser-guided munition accuracy. Fog and low clouds will block the laser-guided munition seeker's field of view which reduces the guidance time. This reduction may affect the probability of hit.

The three generations of Paveway LGB technology exist, each successive generation representing a change or modification in the guidance mechanism. Paveway I was a series of laser guided bombs with fixed wings. Paveway II [with retractable wings] and Paveway III are the Air Force designations for 500- and 2,000-pound-class laser-guided bombs (LGBs). A guidance control unit is attached to the front of the bomb, and a wing assembly is attached on the rear. Both generations are compatible with current Army, Navy (Marine), and Air Force designators. Paveway II and III have preflight selectable coding. Paveway III is the third-generation LGB, commonly called the low-level laser-guided bomb (LLLGB). It is designed to be used under relatively low ceilings, from low altitude, and at long standoff ranges.

Designation Guideance System Munition GBU-2 KMU-421/B SUU-54/b 2000-lb cluster bomb PAVEWAY I GBU-10 A/B KMU-351 A/B Mk 84 2000-lb bomb GBU-12 A/B KMU-388 A/B Mk 82 500-lb SNAKEYE GBU-12 A/B KMU-420 /B Mk 20 Mod 2 ROCKEYE 500-lb bomb GBU-12 A/B KMU-342 /B M117 750-lb bomb PAVEWAY II GBU-10 D/B KMU-351 E/B Mk 84 2000-lb bomb GBU-12 C/B KMU-388 C/B Mk 82 SNAKEYE 500-lb bomb GBU-16 C/B KMU-455 /B Mk 83 1000-lb bomb

During Desert Storm, the F-111F and the F-117 accounted for the majority of the guided bomb tonnage delivered against strategic targets. The Navy's A-6E capability to deliver LGBs was used only sparingly, despite the fact that the 115 A-6Es deployed constituted almost 51 percent of all US LGB-capable aircraft on the first day of Desert Storm. laser

sensor systems demonstrated degradation from adverse weather, such as clouds, rain, fog, and even haze and humidity.

Videotapes of LGBs precisely traveling down ventilator shafts and destroying targets with one strike, like those televised during and after Desert Storm, can easily create impressions about the effect of a single LGB on a single target, which was summed up by an LGB manufacturer's claim for effectiveness: "one target, one bomb." The implicit assumption in this claim is that a target is sufficiently damaged or destroyed to avoid needing to hit it again with a second bomb, thus obviating the need to risk pilots or aircraft in restrikes. However, evidence does not support the claim for LGB effectiveness summarized by "one target, one bomb." In one sample of targets from Desert Storm, no fewer than two LGBs were dropped on each target; six or more were dropped on 20 percent of the targets; eight or more were dropped on 15 percent of the targets. The average dropped was four LGBs per target.

In Desert Storm, 229 US aircraft were capable of delivering laser-guided munitions. By 1996 the expanded installation of low-altitude navigation and targeting infrared for night (LANTIRN) pods on F-15Es and block 40 F-16s had increased this capability within the Air Force to approximately 500 platforms.

Byproducts/WastePropellants and explosives used in warheads are toxic if introduced into water supplies. Residual amounts of these materials must be collected and taken to a designated disposal site for burning. Each state maintains its own policy pertaining to the disposal of explosives, and Federal regulations require that disposal sites be inspected periodically. Effluents (liquid byproducts) from the chromium coating process can also be hazardous. This problem is best dealt with by storing the effluents in leak-proof containers. As an additional safety precaution, all personnel involved in handling any hazardous wastes should be given protective clothing that includes breathing devices, gloves, boots and overalls.

MODERN LASER-GUIDED MISSILESModern laser-guided missiles can be self-detonated, thus requiring only a single aircraft, and their range has increased significantly. The laser-guided missiles use a laser of a specific frequency bandwidth to locate the target. The pilot must line up the crosshairs and lock successfully onto target. This laser creates a heat signature on the target. The weapon must be released during a certain window of opportunity. After it is launched, the missile uses its onboard instrumentation to find the heat signature. The target is acquired when the missile locates the heat signature. The missile is able to secure the target even if the target is moving.

Laser-guided missiles work by following the reflected light of a laser beam, which can either be shone on the target by the aircraft itself, by another airplane, or by ground troops with a handheld laser designator. Therefore, once the missile has been launched its own instrumentation is able to remain on target, rather than older laser-guided missiles

that required the pilot to continually sight the target with the laser. Laser-guided missiles are used for those targets that need pinpoint accuracy. A disadvantage of laser-guided missiles is that their guidance systems do not work well in all weather conditions. If it is cloudy, the water droplets in the air cause the laser to diffract. Because the laser only operates within a certain bandwidth, the laser can be completely diffracted if it is too cloudy and the missile will not be able to locate its target. Rain has a similar effect on the laser because each raindrop serves to diffract the laser beam, once again deterring the missile from its target.

The FutureFuture laser guided missile systems will carry their own miniaturized laser on board, doing away with the need for target designator lasers on aircraft. These missiles, currently under development in several countries, are called "fire-and-forget" because a pilot can fire one of these missiles and forget about it, relying on the missile's internal laser and detecting sensor to guide it towards its target. A further development of this trend will result in missiles that can select and attack targets on their own. Once their potential has been realized, the battlefields of the world will feel the deadly venom of these "brilliant missiles" for years to come. An even more advanced concept envisions a battle rifle for infantry that also fires small, laser guided missiles. Operation Desert Storm clearly showed the need for laser guided accuracy, and, as a result, military establishments dedicated to their missions will undoubtedly invent and deploy ever more lethal versions of laser guided missiles.

REFFERENCEwebsitewww.sgspires.comwww.wiki.garrysmod.comwww.en.wikipedia.orgwww.nd.edubooksJP 3-09.1, Joint Laser Designation Procedures, 1 June 1991, [PDF Size = 835K but well worth the wait] Joint Laser Designation Procedures Training and Doctrine Command Procedures Pamphlet 34-3 Safety information Laser Fire Control Systems Mil-Handbook-828, 1993 Fundamentals of Lasers LASER RANGE SAFETY Range Commanders Council, White Sands Missile Range, OCTOBER 1998

Laser Guided Munitions CHAPTER 7 TACTICS, TECHNIQUES, AND PROCEDURES FOR THE STRIKE / RECON PLATOON (STRIKER) Techno-Tips on Laser Guided Bombs