Z marker beacon. [JP 1-02] (DoD, NATO) A type of radio beacon, the emissions of which radiate in a vertical cone shaped pattern.
Z-scale. [JP 1-02] (DoD, NATO) On an oblique photograph, the scale used in calculating the height of an object.
zero point. [JP 1-02] (DoD) The location of the center of a burst of a nuclear weapon at the instant of detonation. The zero point may be in the air, or on or beneath the surface of land or water, dependent upon the type of burst, and it is thus to be distinguished from ground zero.
zero-length launching. [JP 1-02] (DoD, NATO) A technique in which the first motion of the missile or aircraft removes it from the launcher.
zippers. [JP 1-02] (DoD) Target dawn and dusk combat air patrol.
zone. See air defense identification zone; air surface zone; combat zone; communications zone; control zone; dead space; demilitarized zone; drop zone; landing zone; rupture zone; safety zone. See also area.
zone I (nuclear). [JP 1-02] (DoD) A circular area, determined by using minimum safe distance I as the radius and the desired ground zero as the center, from which all armed forces are evacuated. If evacuation is not possible or if a commander elects a higher degree of risk, maximum protective measures will be required.
zone II (nuclear). [JP 1-02] (DoD) A circular area (less zone I), determined by using minimum safe distance II as the radius and the desired ground zero as the center, in which all personnel require maximum protection. Maximum protection denotes that armed forces personnel are in "buttoned up" tanks or crouched in foxholes with improvised overhead shielding.
zone III (nuclear). [JP 1-02] (DoD) A circular area (less zones I and II), determined by using minimum safe distance III as the radius and the desired ground zero as the center, in which all personnel require minimum protection. Minimum protection denotes that armed forces personnel are prone on open ground with all skin areas covered and with an over-all thermal protection at least equal to that provided by a two-layer uniform.
zone fire. Artillery or mortar fires that are delivered in a constant direction at several quadrant elevations. See also fire.
zone of action. [JP 1-02] (DoD, NATO) A tactical subdivision of a larger area, the responsibility for which is assigned to a tactical unit; generally applied to offensive action. See also sector.
zone of fire. [JP 1-02] (DoD) An area into which a designated ground unit or fire support ship delivers, or is prepared to deliver, fire support. Fire may or may not be observed. See also contingent zone of fire.
zoom. To scale a display so that it is magnified or reduced on the screen.
Zulu Time. Greenwich Mean Time (GMT) See Universal Time.