API Reference > imodeljs-common > Geometry > HorizontalCRS > ellipsoid ellipsoid Readonly ellipsoid: undefined | GeodeticEllipsoid The complete definition of the geodetic ellipsoid referred to by ellipsoidId. It can also be used if the ellipsoid is not stored in either service or dictionary. This property is exclusive of having datumId and datum properties undefined. Defined in core/common/src/geometry/CoordinateReferenceSystem.ts Line 177 Last Updated: 11 June, 2024