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).

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.

Categories of guidance systems

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.

GOT systems

In every GOT system there are three subsystems:

• Target tracker
• Missile tracker
• Guidance computer

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

• Remote Control Guidance: The guidance computer is on the launcher. The target tracker is also placed on the launching platform.
• Homing Guidance: The guidance computers are in the missile and in the target tracker.