Precision-guided munition

A precision-guided munition (PGM, smart weapon, smart munition, smart bomb) is a guided munition intended to precisely hit a specific target, and to minimize collateral damage.

Because the damage effects of explosive weapons decrease with distance due to an inverse cube law, even modest improvements in accuracy (hence reduction in miss distance) enable a target to be attacked with fewer or smaller bombs. Thus, even if some guided bombs miss, fewer air crews are put at risk and the harm to civilians and the amount of collateral damage may be reduced.

The advent of precision-guided munitions resulted in the renaming of older bombs "unguided bombs", "dumb bombs", or "iron bombs".

Types

Recognizing the difficulty of hitting moving ships during the Spanish Civil War, the Germans were first to develop steerable munitions, using radio control or wire guidance. The U.S. tested TV-guided (GB-4),semi-active radar-guided (Bat), and infrared-guided (Felix) weapons.

Radio-controlled weapons