API Reference > imodeljs-common > Geometry > GeodeticEllipsoid GeodeticEllipsoid Class This class defines the mathematical model of the Earth shape in the form of an ellipsoid. There are various ways to define an ellipsoid but we have retained the definition based on the polar and equatorial radiuses. The other ellipsoid properties, such as flattening and inverse flattening, can be obtained using the simple equations that are defined at: https://en.wikipedia.org/wiki/Flattening and https://en.wikipedia.org/wiki/Earth_ellipsoid. The present class only implements the definition of the ellipsoid. No processing is performed here. If ellipsoid based computation are required refer to GeodeticEllipsoid.Ellipsoid in core/geometry package. The class only serves to describe a geodetic ellipsoid and can be partially or fully defined. For a lot of purposes simply setting the id property is sufficient to describe the ellipsoid in most cases as the mathematical properties (equatorial and polar radiuses) will be often extracted from the dictionary of commonly known ellipsoids by the reprojection engine used. Implements GeodeticEllipsoidProps Methods Name Description constructor(data?: GeodeticEllipsoidProps): GeodeticEllipsoid equals(other: GeodeticEllipsoid): boolean Compares two Geodetic Ellipsoid. toJSON(): GeodeticEllipsoidProps Creates a JSON from the Geodetic Ellipsoid definition fromJSON(data: GeodeticEllipsoidProps): GeodeticEllipsoid Static Creates a Geodetic Ellipsoid from JSON representation. Properties Name Type Description deprecated Readonly boolean If true then indicates the definition is deprecated. description Readonly undefined | string Description of the ellipsoid epsg Readonly undefined | number The EPSG code of the ellipsoid. equatorialRadius Readonly undefined | number The equatorial radius of the ellipsoid in meters. id Readonly undefined | string Ellipsoid key name polarRadius Readonly undefined | number The polar radius of the ellipsoid in meters. source Readonly undefined | string The textual description of the source of the ellipsoid definition. Defined in core/common/src/geometry/GeodeticEllipsoid.ts Line 50 Last Updated: 12 June, 2024