ACLOS

Missile guidance refers to a variety of methods of guiding a missile or a guided bomb to its intended target. The missile's target accuracy is a critical factor for its effectiveness. Guidance systems improve missile accuracy by improving its "Single Shot Kill Probability" (SSKP), which is part of combat survivability calculations associated with the salvo combat model.

These guidance technologies can generally be divided up into a number of categories, with the broadest categories being "active," "passive" and "preset" guidance. Missiles and guided bombs generally use similar types of guidance system, the difference between the two being that missiles are powered by an onboard engine, whereas guided bombs rely on the speed and height of the launch aircraft for propulsion.

The concept of missile guidance originated at least as early as World War I, with the idea of remotely guiding an airplane bomb onto a target.

In World War II, guided missiles were first developed, as part of the German V-weapons program.Project Pigeon was American behaviorist B.F. Skinner's attempt to develop a pigeon-guided missile.

The first U.S. ballistic missile with a highly accurate inertial guidance system was the short-range Redstone.

Guidance systems are divided into different categories according to what type of target they are designed for - either fixed targets or moving targets. The weapons can be divided into two broad categories, Go-Onto-Target (GOT) and Go-Onto-Location-in-Space (GOLIS) guidance systems. A GOT missile can target either a moving or fixed target, whereas a GOLIS weapon is limited to a stationary or near-stationary target. The trajectory that a missile takes while attacking a moving target is dependent upon the movement of the target. Also, a moving target can be an immediate threat to the sender of the missile. The target needs to be eliminated in a timely fashion in order to preserve the integrity of the sender. In GOLIS systems the problem is simpler because the target is not moving .

In every Go-Onto-Target system there are three subsystems:

The way these three subsystems are distributed between the missile and the launcher result in two different categories:

These guidance systems usually need the use of radars and a radio or wired link between the control point and the missile; in other words, the trajectory is controlled with the information transmitted via radio or wire (see Wire-guided missile). These systems include:

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