Large Radar System

Large Radar is the best available until Hyper-Wawe Decoder.

[ NKF: Actually, they don't. Only one small radar and one large radar will be able to stack. Multiple radars of the same type do not - and only cost more money. The large radar awards 20 short and 20 long range scanning for the base, the small radar gives it 10 short range scanning. When building multiple large radars, your base's scanning ability is only improved by 20 short and 20 long. Adding a small radar boosts short range detection to 30. ] {ok, never could actually get definitive proof, maybe the aliens were just increasing their UFO numbers, so it looked like better detection.}