A laser-guided bomb (LGB) is a guided bomb that uses semi-active laser guidance to strike a designated target with greater accuracy than an unguided bomb. First developed by the United States during the Vietnam War, laser-guided bombs quickly proved their value in precision strikes of difficult point targets. These weapons use on-board electronics to track targets that are designated by laser, typically in the infrared spectrum, and adjust their glide path to accurately strike the target. Since the weapon is tracking a light signature, not the object itself, the target must be illuminated from a separate source, either by ground forces, by a pod on the attacking aircraft, or by a separate support aircraft.
Data from the 28,000 laser guided bombs dropped in Vietnam showed that laser-guided bombs achieved direct hits nearly 50% of the time, despite the laser having to be aimed out the side window of the back seat of another aircraft in flight. Unguided bombs had an accuracy rate of just 5.5% per mission, which usually included large numbers of the munitions. Because of this dramatically higher precision, laser-guided munitions can carry less explosive and cause less collateral damage than unguided munitions. Today, laser-guided bombs are one of the most common and widespread guided bombs, used by many of the world's air forces.
