The JDAM (Joint Direct Attack Munition) is not a standalone bomb but a guidance kit installed on conventional free-fall bombs to convert them into precision-guided munitions. Designed and produced by Boeing, the kit can be mounted on bombs weighing approximately 227 kg (500 lb), 454 kg (1000 lb), and 907 kg (2000 lb).
The JDAM utilizes a dual navigation system combining Inertial Navigation (INS) and GPS. While GPS provides exact positioning and corrects trajectory errors, it can be vulnerable to signal disruption. The inertial system, using internal sensors to calculate motion and direction, allows guidance to continue independently without external signals, ensuring reliable performance in various weather and environmental conditions.