LASER GUIDED MISSILES

ABSTRACT Laser guidance is a technique of guiding a missile or other

projectile or vehicle to a target by means of a laser beam. Some laser guided systems utilize beam riding guidance, but

most operate more similarly to semi-active radar homing (SARH). With this technique, a laser is kept pointed at the as “painting

the target”, or “laser painting”). The missile, bomb, etc. is launch target and the laser radiation

boun.ces off the target and is scattered in all directions dropped somewhere near the target.

When it is close enough that some of the reflected laser energy from the target reaches it, a laser seeker detects which direction this energy is coming from and adjusts the projectile trajectory towards the source.

As long as the projectile is in the general area and the laser is kept aimed at the target, the projectile should be guided accurately to the target.

Note that laser guidance is not useful against targets that do not reflect much laser energy, including those coated in special paint which absorbs laser energy.

INTRODUCTION Laser guidance is a technique of guiding a missile or other

projectile or vehicle to a target by means of a laser beam. Some laser guided systems utilize beam riding guidance, but most operate more similarly to semi-active radar homing (SARH)

This technique is sometimes called SALH, for Semi-Active Laser Homing.

With this technique, a laser is kept pointed at the target and the laser radiation bounces off the target and is scattered in all directions (this is known as “painting the target”, or “laser painting”).

Laser guidance is not useful against targets that do not reflect much laser energy, including those coated in special paint which absorbs laser energy.

This is likely to be widely used by advanced military vehicles in order to make it harder to use laser rangefinders against them and harder to hit them with laser- guided missiles.

An obvious circumvention would be to aim the laser merely close to the target.

BACK GROUND 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

The accuracy of these weapons earned them the well-known sobriquet of "smart weapons.“

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.

The laser guided missile has established itself as a key component in today's high-tech military technology.

SEMI ACTIVE RADAR HOMING Semi-active radar homing, or SARH, is a common type of missile

guidance system. The name refers to the fact that the missile itself is only a passive

detector of a radio signal – provided by an external (“off board”) source — as it reflects off the target.

The basic concept of SARH is that since almost all detection and tracking systems consist of a radar system, duplicating this hardware on the missile itself is redundant.

In addition, the resolution of a radar is strongly related to the physical size of the antenna, and in the small nose cone of a missile there isn't enough room to provide the sort of accuracy needed for guidance.

In the SARH system the missile listens for the reflected signal at the nose, and is still responsible for providing some sort of “lead” guidance.

MISSILE COMPONENTS

Guided missiles are made up of a series of subassemblies

The various subassemblies form a major section of the overall missile to operate a missile system, such as guidance, control, armament (warhead and fuzing), and propulsion.

The major sections are carefully joined and connected to each other. They form the complete missile assembly.

The arrangement of major sections in the missile assembly varies, depending on the missile type.

The guidance section is the brain of the missile. It directs its maneuvers and causes the maneuvers to be executed by the control section

The armament section carries the explosive charge of the missile, and the fuzing and firing system by which the charge is exploded.

The propulsion section provides the force that propels the missile.

Guidance and Control SectionThe complete missile guidance system includes the electronic sensing systems that

initiate the guidance orders and the control system that carries them out. The elements for missile guidance and missile control can be housed in the same

section of the missile, or they can be in separate sections. In the active homing system, target illumination is supplied by a component

carried in the missile, such as a radar transmitter. ARMAMENT SECTION Payload The payload is usually considered the explosive charge, and is carried in the

warhead of the missile. Fusing The fuzing and firing system is normally located in or next to the missile's warhead

section. It includes those devices and arrangements that cause the missile's payload to function in proper relation to the target.

Safety and Arming (S&A) Devices S&A devices are electromechanical, explosive control devices. They maintain the

explosive train of a fuzing system in a safe (unaligned) condition until certain requirements of acceleration is met after the missile is fired.

MISSILE CONTROL SYSTEMThe heart of a missile is the body, equivalent to the fuselage of an aircraft. The missile body contains the guidance and control system, warhead, and propulsion system. Some missiles may consist of only the body alone, but most have additional surfaces to generate lift and provide maneuverability.

A generic missile configuration equipped with all three surfaces. Often times, the terms canard, wing, and fin are used interchangeably, which can get rather confusing.

wing is a relatively large surface that is located near the center of gravity while a canard is a surface near the missile nose and a tail fin is a surface near the aft end of the missile.

THE MANUFACTURING PROCESSA 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, an the warheadThe 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

FINAL ASSEMBLYInsertion 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 accidentsSimple 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 warheadThe manufacturer has successfully constructed on of the most complicated, sophisticated, and potentially dangerous pieces of hardware in use today.

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.

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.

ADVANTAGES OF LASER GUIDED MISSILES

This concept of operation places high priority on target designation capabilities, deployed close to the target by unmanned platforms and Special Forces.

Laser guided weapons, such as the Lockheed Martin and Lahat and Nimrod, developed by IAI/MBT offer many advantages for heliborne and airborne use.

THE FUTURE LASER GUIDED MISSILESFuture 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.

CONCLUSION"In World War II it could take 9,000 bombs to

hit a target the size of an aircraft shelter. In Vietnam, 300.Today we can do it with one laser-guided missile. Laser guided missile can be fired at targets ranging 8 to 13 kilometers and some like LAHAT laser guided missile up to 22 kilometers. Though many missiles are developed, they don’t find accuracy as in the reaching the target. Laser guided missile has be one of dangerous missile in war field in past and will be the future.

THANQ…….

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