The Sentry Post is a Turret that is available in Tech Level 1. It costs 20 Carbon and 10 Ore, and though it cannot attack, it has an excellent Line of Sight. It can also see stealthed units. For this reason, players should build Sentry Posts to stop stealthed units from sneaking past the player's defensive structures.
"These cheap Tech Level 1 structures are fixed reconnaissance outposts, and have no actual offensive capabilities. However, they are equipped with advanced long-range sensors that can detect otherwise invisible units, such as Jedi and Sith, and submersible vehicles."