Watchtower

The Watchtower building is a way to enter the Intel Mission screen. It can also be entered by selecting the compass icon from the main UI on the World Map. The building itself has no upgrades that can be made to the building itself.

That said, the Intel Missions have an Intel Level that goes up to level 20. As you complete more Intel Missions, the Intel Level will eventually increase. When the Intel Level increases, rarer missions will be more likely to spawn.

When a new Intel Level is reached, a full set of additional Intel Missions will immediately spawn. Also, Rebel Bounty missions count for Increasing Intel Level. This means that the more Rebel Bounty missions you do early in the game, the quicker you can accelerate the rewards you receive from all Intel Missions. This small trick can increase the tempo of your early game account.