They must provide air defense day or night in all weather conditions. Mobility contributes directly to continuity. The inventory of air defense weapons includes a variety of missiles, guns, and support equipment. Air defense weapons exist at nearly every level. Some fire control radars also have limited target-acquisition capability.
Radars work as systems rather than as separate units.
Air defense planners at all levels integrate radars into an overall system of coverage. Army early warning battalions deploy their radars 10 km or so from the line of contact. Battalions of the army-group's early warning regiment or brigade establish a second line of radar posts about 50 km behind the first to give depth. The air surveillance radar network is difficult to avoid or defeat. Large numbers of radars are highly mobile and can quickly displace.