Standard ARM guided missiles are air-launched, supersonic guided missiles employed against surface targets that radiate microwave electromagnetic energy. Tactical configurations of the Standard ARM guided missile currently in use are the AGM-78B, AGM78C, and AGM-78D-1. Current training configurations are the ATM-78B, ATM-78C, and ATM-78D-1.
The missile is ejection launched from the A-6 aircraft, which is capable of carrying four launcher/missile combinations. The major differences between the various AGM-78 missile configurations are the guidance sections and smoke signals.
The AGM-78 missile consists of six cylindrical sections (guidance section, ordnance section, auto-pilot-battery section, dual-thrust rocket motor, spacer assembly, and steering control unit) and four fixed-dorsal fins located in line with four independently movable control surfaces (tail).
The AGM-78 missile uses a passive homing guidance system to develop guidance intelligence from the energy radiated by the target. The missile control system uses this guidance intelligence with pre-launch instructions from the launch aircraft avionics and feedback from missile instruments to develop steering commands, which control the deflections of four aerodynamic control surfaces (tail). These tail deflections steer the missile on an optimum course to the target. Propulsive power is provided by a dual-thrust rocket motor (DTRM), which is fired shortly after the missile is ejected from the launcher. Electrical power is provided by primary batteries that are activated shortly before launch. Target destruction is accomplished by a warhead detonated by a fuze system. The missile impact area is identified by a guided missile smoke signal. This smoke signal uses a white phosphorous marking agent that is dispersed when the smoke signal canister is broken by the warhead explosion.