Observation drones are automated terran detector units. They are tasked with the patrol of installations, capable of detecting cloaked foes.
Observation drones appear in the bonus map Deception. They are represented by the science vessel, though do not use any abilities apart from detection.
Should a drone be attacked, it will automatically retreat from the source of fire. After a while, it will return to its pre-established patrol route.
StarCraft: Brood War. Vivendi Games. Mission: Deception (in English). Map Archives: Deception.