How is visibility measured?

Visibility is commonly measured in miles or fractions thereof, which indicates how far one can see from a specific point to the horizon. This measurement is crucial for aviation operations, as it directly affects flight safety, approach, and landing procedures. The ability to see clearly over a distance is essential for pilots to navigate and identify obstacles, other aircraft, and runway conditions during critical phases of flight.

In contrast, measuring visibility based on passengers or cloud cover does not provide an accurate or relevant representation of how far one can see in the context of aviation. These factors relate more to different operational metrics rather than the actual visibility measurement required for flight operations and safety protocols. Thus, the most accurate and practical method for measuring visibility in aviation contexts is the distance to the horizon in miles or fractions.