Plane can be considered the longitude plane because the great circle made by its intersection with sphere S is always a line of longitude. Plane can be considered the tangent plane since it always contains a line tangent to circle C at point P. The dihedral angle between planes and is angle , the angle of interest.
Plane can be considered the elevation plane and it stays perpendicular to plane and passes through sphere center SO and point P. The smallest angle between the cardinal axis of the sphere and plane is angle , or ∠SNSOP.
Point P can be defined as an arc length along circle C equal to angle , or ∠SNCOP.
The angle between the axis of cone N and the cardinal axis of sphere S is angle , or ∠SNSOCO.