Specialized fire-control radars have replaced earlier optical range finders and electromechanical computers for determining target range and bearing for aiming ground-based artillery or shipboard guns. Specialized radars have also been developed that can determine the locations of hidden enemy gun positions by extrapolating data obtained by tracking incoming projectiles.

Other radar fire-control systems aim and guide ground-to-ground, ground-to-air, air-to-air and air-to-ground missiles. Radar systems that support ground and shipboard missile launchers provide instantaneous target position and relative motion data as well as the beams for guiding "beam-riding" missiles. Airborne radars provide comparable capability for aircraft-launched air-to-air and air-to-ground missiles.

Antimissile missiles are designed to home in on active radar or jamming transmitters operating either as pulsed- or continuous-wave systems. The only defense for a radar installation against attack by a radio-frequency-sensitive missile is infrequent and random transmission of RF and the immediate shutdown of its transmitter when it has been warned of possible attack. Independent guidance systems on air- or ground-launched missiles can make the necessary course corrections to reach the target area, and radar fuses can detonate warheads at some distance from the target without actually striking it. Cruise missiles with a range of about 500 mi (800 km) carry onboard navigation systems based on GPS guidance or computerized map reading to make pinpoint strikes on designated targets.

Active laser range finders can determine the precise range of targets for conventional artillery or guns mounted on mobile platforms such as tanks. Lasers can also...