Air Defense Artillery refers to a number of short-range and point-defense air defense systems used by the United States Colonial Marine Corps. While sufficient in engaging an enemy closing with the systems, some Marines have complained about their ability to track crossing targets or those using jamming equipment, comparing them to throwing rocks at the enemy.
The M5879 is a 20mm quad gatling system mounted on an M570-series chassis. The system is controlled by a multi-spectrum sensor, allowing it to track and defeat hypervelocity targets at ranges of up to 1,500m using armor-piercing and high-explosive shells.
The M270 is a mobile phased plasma gun array, the same technology found in the M78 PIG, used to engage targets within its line-of-sight. It is one of the few ADA systems capable of destroying artillery shells in mid-flight.
The M820 is a rapid-pulsing free-electron 40mW laser. It uses its beam as lidar to track targets before engaging them with a high-energy beam. Against missiles, the M820 can be fired on a continuous-wave "dazzle" mode to blind optical and infrared sensors, as well as blind enemy infantry. This latter use is expressly forbidden by the Geneva Convention.