WordNet
n. a method of controlling the flight of a missile by commands originating from the ground or from another missile
Wikipedia
Command guidance is a type of missile guidance in which a ground station or aircraft relay signals to a guided missile via radio control (or possibly through a wire connecting the missile to the launcher: Wire-guided missile) and tell the missile where to steer in order to intercept its target. Additionally, it is possible to send a command to the missile to detonate, even if the missile itself has a fuze or fuzes. (It may be possible to detonate the missile and destroy or damage the target, even though the missile was not actually going to strike the target, due to the blast radius of the warhead).
Typically, the system giving the guidance commands is tracking both the target and the missile or missiles via radar. It determines the position and velocity of the target and the position and velocity of the missile and calculates whether their paths will intersect. If not, the guidance system will relay commands to the missile(s), telling them to move their fins in such a way to steer themselves in the direction necessary for them to end up on an interception course with the target. If the target maneuvers, the guidance system can notice this and update the missiles' course continuously to counteract the maneuvering. If the missile passes close to the target, either its own proximity or contact fuze will detonate the warhead, or the guidance system can estimate when the missile will pass near the target and send a detonation signal.
On some systems there is a dedicated radio antenna or antennas for communicating with the missile(s). On others, the radar itself is actually able to send coded pulses which the missile can pick up and interpret as guidance commands. Sometimes to aid the tracking station, the missile will contain a radio transmitter, making it easier to track. Also, sometimes there is a dedicated radar antenna on the tracking station for tracking the missile as well as one or more for tracking targets. It is especially these types of systems which may be able to communicate with the missile via the same radar energy it uses for tracking it.
Usage examples of "command guidance".
His pattern of operation in thirty years of business had been to provide command guidance, then let a team of subordinates work out the details while he moved on to other strategic issues, and he'd fully expected it to go easier in this case rather than harder.
When he had been forced to operate without Command guidance in the past, the situations he had usually faced were so critical that he had had only minutes or seconds to make his decisions.
It was, in fact, a command complex whose main feature was an operations rooms with maps, a bank of closed-circuit television monitors and a panel for firing SLAM (surface-launched air missile), which is simply a cluster of Blowpipe missiles mounted on a pylon with an electronic package for remote-control firing and radio-command guidance.