The Joint Direct Attack Munition (JDAM) is a guidance kit that converts unguided bombs, or “dumb bombs”, into all-weather precision-guided 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.
The JDAM is not a stand-alone weapon; rather it is a “bolt-on” guidance package that converts unguided gravity bombs into precision-guided munitions (PGMs). The key components of the system consist of a tail section with aerodynamic control surfaces, a (body) strake kit, and a combined inertial guidance system and GPS guidance control unit.
The JDAM was meant to improve upon laser-guided bomb and imaging infrared technology, which can be hindered by bad ground and weather conditions. Laser seekers are now being fitted to some JDAMs.
From 1998 to November 2016, Boeing completed more than 300,000 JDAM guidance kits. In 2017, it built more than 130 kits per day. More details