Ellipsoid

Definitions

1. A surface, all of whose cross sections are elliptic or circular (including the sphere), that generalises the ellipse and in Cartesian coordinates (x, y, z) is a quadric with equation x²/a² + y²/b² + z²/c² = 1.
2. Such a surface used as a model of the shape of the earth.

Equivalents

Examples

“Polarizability can be imagined as a three-dimensional ellipsoid centred on the centre of the molecule, as shown in Figure⟳ 10.4.”

“Because only ellipsoids of rotation have⟳ been adopted in practical geodesy and surveying and triaxial ellipsoids have⟳ been limited to theoretical studies, we will use⟳ the term ellipsoid for brevity to mean⟳ ellipsoid of rotation.”

“As mentioned before, modern geodetic datums rely⟳ on the surfaces of geocentric ellipsoids to approximate the surface of the earth.”

“Here the geoid is thirty meters below the ellipsoid.”

CEFR level