smart bomb - Cannon Launched Guided Projectiles

Precision-guided munitions (PGMs, smart munitions, smart bombs, guided bomb units or GBUs) are guided weapons intended to precisely hit a specific target, and to minimise damage to things other than the target.[1] Because the damage effects of an explosive weapon fall off with distance according to a power law, even modest improvements in accuracy (and hence reduction in miss distance) enable a target to be effectively attacked with fewer or smaller bombs. Thus, even if some bombs miss, fewer air crews are put at risk and the harm to civilians is somewhat reduced. The creation of precision-guided munitions resulted in the renaming of older bombs as "gravity bombs", "dumb bombs" or "iron bombs". A guided bomb differs from a guided missile in that a bomb relies on the speed and height of the launch aircraft for propulsion, whilst a missile has an onboard engine.

Cannon Launched Guided Projectiles
A Cannon Launched Guided Projectile (CLGP), a precursor to modern PGMs, is fired from artillery, ship's cannon, or armored vehicle. Several agencies and organizations sponsored CLGP programs. The United States Navy sponsored the "Deadeye" program, a laser-guided shell for its 5" guns[15] and a program to mate a Paveway guidance system to an 8" shell[16] for the 8"/55 caliber Mark 71 gun in the 1970s (Photo). Other Navy efforts include the BTERM, ERGM, and LRLAP shells.
The U.S. Army's MGM-51 Shillelagh missile can be considered a type of CLGP. Intended for use on the M551 Sheridan light tank, the Shillelagh missile was fired out of the Sheridan's cannon to provide robust anti-tank capability. The Army's M712 Copperhead laser guided artillery round was used in Desert Storm. Army CLGPs include the XM982 Excalibur 155mm artillery shell, the XM395 Precision Guided Mortar Munition, and the XM1156 Precision Guidance Kit to refit existing 155mm shells with precision guidance, as the Air Force's JDAM program converts dumb bombs into precision munitions.