Joint Direct Attack Munition
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![OCD First Flight Test of the first GPS-guided weapon, a direct hit on the target, Eglin Air Force Base, on February 10, 1993.](/Images/godic/202501/21/First_gps_weapon_OCD0555.jpg")
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![GBU-38 explosions in Iraq in 2008.](/Images/godic/202501/21/GBU-38_munition_explosions_in_Iraq0555.jpg")
The Joint Direct Attack Munition (JDAM) is a guidance kit that converts unguided bombs, or "dumb bombs" into all-weather "smart" munitions. JDAM-equipped bombs are guided by an integrated inertial guidance system coupled to a Global Positioning System (GPS) receiver, giving them a published range of up to 15 nautical miles (28 km). JDAM-equipped bombs range from 500 pounds (227 kg) to 2,000 pounds (907 kg). When installed on a bomb, the JDAM kit is given a GBU (Guided Bomb Unit) nomenclature, superseding the Mark 80 or BLU (Bomb, Live Unit) nomenclature of the bomb to which it is attached.