Self-propelled anti-aircraft gun (SPAAG) or self-propelled air defense system (SPAD), is a mobile vehicle with a dedicated anti-aircraft capability.
Specific weapon systems used include machine guns, autocannons, larger guns, or missiles, and some mount both guns and longer-ranged missiles (e.g. the Pantsir-S1). Platforms used include both trucks and heavier combat vehicles such as armored personnel carriers and tanks, which add protection from aircraft, artillery, and small arms fire for front line deployment.