Spherical Ellipse Construction
- Let there be a fixed circle C with center F1 on a sphere.
- Let there be a fixed point F2 inside the circle, not coincide with F1.
- Let P be a point on C.
- Let t be a line perpendicular to line[P, F2] and intersect midpoint[P, F2]
- Let Q be the intersection[line[F1,P], line[t]]
- As Q move about, Q traces out an ellipse, and t is its tagent at Q.
Note: t forms a great circle. F1 and F2 are the foci.
Spherical Ellipse with Osculating Circles
Spherical Ellipse with Different Eccentricies