The same reach as the angle at the centre of the Earth that subtends it, in degrees, rather than as a distance along the ground: the Footprint is a spherical cap, and this is its angular radius, the form every calculation on the sphere takes it in.
The same reach as the angle at the centre of the Earth that subtends it, in degrees, rather than as a distance along the ground: the Footprint is a spherical cap, and this is its angular radius, the form every calculation on the sphere takes it in.