The 120 mm Gun M1 was the United States Army's standard super-heavy anti-aircraft gun during World War II and the Korean War, complementing the smaller and more mobile M2 90 mm gun in service. Its maximum altitude was about 60,000 ft (18,000 m), which earned it the nickname stratosphere gun.
A 120 mm M1 anti-aircraft gun at US Army Ordnance Museum.
Anti-aircraft warfare is the counter to aerial warfare and it includes "all measures designed to nullify or reduce the effectiveness of hostile air action". It includes surface based, subsurface, and air-based weapon systems, associated sensor systems, command and control arrangements, and passive measures. It may be used to protect naval, ground, and air forces in any location. However, for most countries, the main effort has tended to be homeland defence. Missile defence is an extension of air defence, as are initiatives to adapt air defence to the task of intercepting any projectile in flight.
Artist's rendition of short and long range AA systems used by the Dutch Joint Ground-based Air Defence Command in 2017.
Ballonabwehrkanone by Krupp
Ballonabwehrkanone by Krupp
Ballonabwehrkanone on the Prussian corvette Nymphe 1872