Air Traffic Control tower improves greatly visibility on the mini map, just like the radar but with much larger distance of view, also the ATC tower scans the map 2x faster then the normal radar.
Updated to version 1.1.x
When attempting to place an ATC tower, I see no distance indication for range on the map. Once I actually place the tower, it turns into a Radar station. Picking it up just gives me a basic radar station instead of a tower.