How is the height of a control tower typically indicated?

The height of a control tower is typically indicated using markings or signage that is placed on or beneath the control tower structure itself. This allows for clear visibility and provides important information to various aircraft and related operations. Such markings ensure that pilots and ground personnel are aware of the tower's height as they navigate the area.

In aviation, proper identification of a control tower's height is crucial for maintaining safe separation distances between the tower and flying aircraft. It helps in flight planning and approach strategies, especially in busy airspace. The clear indication of the height supports operational safety, especially during takeoff and landing phases.

The other options do not typically serve as standard indicators of height. For instance, while the color of the tower might play a role in visibility or identification, it does not provide specific height information. Markings on the building's side can be relevant, but the most standardized practice includes dedicated signage under or on the control tower, making that indication the most common and reliable method. Radar readings pertain to tracking aircraft rather than measuring structural heights, and thus are not relevant to the indication of control tower heights.