Sensor tower

The Sensor Tower was a Terran building to be featured in StarCraft II. It has since been canceled

Overview
A sensor tower used passive and active thermal and electromagnetic scanning along with input from seismic sensors and Doppler analysis, enabling it to pinpoint any target within range. Even foes hiding behind terrain features can be detected, although they won't be identified without visual verification. The multi-spectrum output enabled foes to easily detect the presence of a sensor tower and identify the location of the base while holds it.

Game Unit
The Sensor Tower could detect cloaked and burrowed units.

Other strategies revolved around "spoofing" the tower with decoy units or simply staying outside its range. Terran commanders have been known to counter by erecting sensor towers in fake base locations just to keep enemies guessing.