Radar Tower

A Radar Tower is a building which is used for revealing an area on the Map. After being powered, it scans the surrounding area every 5 minutes up to 10 times, increasing in range with each scan. The starting range is based on the height and line-of-sight of the tip of the tower, so placing it at the highest elevation possible for maximum efficiency. Any terrain at an elevation higher than its tip, or area blocked by a terrain feature such as the stone arch near the grass field will not be revealed.

This is acquired via Crystal Oscillator research: Tier 5 -- Radar Technology

Coverage

 * Four well-placed radar towers on the natural high point will cover the entire map with a minimal black (unexplored) area remaining.
 * A single radar tower placed at 3km height (near the build limit height, or about the same height as tip of the space elevator) will reveal the entire map, if built at the center of the map.

Trivia

 * Both Radar Tower and Space Elevator have the collision box height of 118m, although the latter has a much taller graphical appearance.
 * Its indicator light which extends out the sideways near the tip of the tower does not counted towards the collision box.