Radar

From Cold War Crisis Wiki

The radar in Cold War Crisis slightly differs from the original game, it is provided from a structure or a unit or an AWACS. It not only activates the mini-map and the warnings systems, but it can also detect enemy aircraft within a certain radius, this means enemy aircraft will be visible (i.e. targetable) for you as it comes within the scanning range, allowing you to build a powerful AA network to counter any type of air attacks that the enemy forces are planning. It also helps targeting for Anti-Air systems.

All Radar-providing vehicles or buildings require fuel to function properly, which means if you are low on fuel you will not have your Radar or minimap. The only exception of this is the E-3 Sentry call-in AWACS, which will work as a long-range radar, providing you the minimap and spotting enemy aircraft with a very long-range as would a normal radar.