API Reference > imodeljs-common > Geometry > HorizontalCRSProps > ellipsoidId ellipsoidId ellipsoidId: undefined | string The identifier of the geodetic ellipsoid as stored in the dictionary or the service database. This property is exclusive of having datumId and datum properties undefined. Defined in core/common/src/geometry/CoordinateReferenceSystem.ts Line 106 Last Updated: 11 June, 2024