Ship gun fire-control systems (GFCS) enable remote and automatic targeting of guns against ships, aircraft, and shore targets, with or without the aid of radar or optical sighting. Most US ships destroyers or larger (but not destroyer escorts or escort carriers) employed GFCS for 5 inch and larger guns, up to battleships such as the USS Iowa. After the 1950s, GCFSs were integrated with missile fire-control systems and other ship sensors.
The major components of a GFCS are a manned director, with or replaced by radar or television camera, a computer, stabilizing device or gyro, and equipment in a plotting room  The brains were first provided by the Mark 1A Fire Control Computer which was an electro-mechanical analog ballistic computer that provided quick and accurate near real-time first-shot hit firing solutions which could automatically control one or more gun mounts against stationary, or moving targets on the surface or in the air. This gave American forces a technological advantage in WWII against the Japanese who did not develop this technology, and still used visual correction of shots with colored splashes. Digital computers would not be adopted for this purpose by the US until the mid 1970s. However, it must be emphasized that all analogue AA fire control systems had severe limitations, and even the USN Mk 37 required nearly 1000 rounds of 5″ mechanical fuze ammunition per kill, even in late 1944. art programmable fuze with six modes: contact, delay, time, and 3 proximity modes.