Great ellipse

For the shortest path between two points on the earth, see geodesics on an ellipsoid.
A spheroid

A great ellipse is an ellipse passing through two points on a spheroid and having the same center as that of the spheroid. Equivalently, it is an ellipse on the surface of a spheroid and centered on the origin, or the curve formed by intersecting the spheroid by a plane through its center.[1] For points that are separated by less than about a quarter of the circumference of the earth, about , the length of the great ellipse connecting the points is close (within one part in 500,000) to the geodesic distance.[2][3][4] The great ellipse therefore is sometimes proposed as a suitable route for marine navigation. The great ellipse is special case of an earth section path.

  1. ^ American Society of Civil Engineers (1994), Glossary of Mapping Science, ASCE Publications, p. 172, ISBN 9780784475706.
  2. ^ Bowring, B. R. (1984). "The direct and inverse solutions for the great elliptic line on the reference ellipsoid". Bulletin Géodésique. 58 (1): 101–108. Bibcode:1984BGeod..58..101B. doi:10.1007/BF02521760. S2CID 123161737.
  3. ^ Williams, R. (1996). "The Great Ellipse on the Surface of the Spheroid". Journal of Navigation. 49 (2): 229–234. Bibcode:1996JNav...49..229W. doi:10.1017/S0373463300013333.
  4. ^ Walwyn, P. R. (1999). "The Great Ellipse Solution for Distances and Headings to Steer between Waypoints". Journal of Navigation. 52 (3): 421–424. Bibcode:1999JNav...52..421W. doi:10.1017/S0373463399008516.