RIM-116 Rolling Airframe Missile

The RIM-116 Rolling Airframe Missile, known as RAM, is a small, lightweight, infrared homing surface-to-air missile used by the navies of Germany, Japan, Greece, Turkey, South Korea, Saudi Arabia, Egypt, Mexico, the United Arab Emirates and the United States. It was originally intended primarily as a point-defense weapon against anti-ship missiles. As its name indicates the missile rolls as it flies: its radio-frequency tracking system uses a two-antenna interferometer that can measure phase interference in only one plane, so constant rolling lets it scan in all directions and only one pair of steering canards is needed. The missiles, the Mark 49 launching system and support equipment make up the RAM Mk 31 Guided Missile Weapon System, and the Mk 144 launcher stores 21 missiles. SeaRAM is a launcher variant with independent sensors derived from the Phalanx close-in weapon system.