API Reference > imodeljs-common > Geometry > GeodeticTransform > sourceEllipsoid sourceEllipsoid Readonly sourceEllipsoid: undefined | GeodeticEllipsoid The identifier of the source geodetic datum as stored in the dictionary or the service database. This identifier is optional and informational only. Defined in core/common/src/geometry/GeodeticDatum.ts Line 369 Last Updated: 11 June, 2024