What is the term for the ratio of the air base length to the altitude at which aerial photographs were taken?

The correct term for the ratio of the air base length to the altitude at which aerial photographs were taken is known as the K Factor. This concept is particularly important in aerial photography and photogrammetry, as it helps to determine the geometric relationships between points on the ground and their corresponding points on the aerial images.

The K Factor is used to scale the coverage area of an aerial image based on the altitude of the flight. By understanding this ratio, surveyors and photographers can accurately interpret images, measure distances, and create maps or models of the land. This aspect of aerial photography is crucial for accurate mapping and surveying applications.

The other terminology, while related to geometry or photography, does not specifically refer to the ratio of the air base length to altitude. The dihedral angle involves the angle between two planes, X and Y tilt refer to the tilting of a camera along the X and Y axes which affects the orientation of images, and a radial line is a straight line from a center point to a boundary, which does not encapsulate the aerial photography ratio. Thus, the K Factor is the most appropriate choice in this context.