API Reference > imodeljs-common > Geometry > VerticalCRS VerticalCRS Class Vertical Coordinate reference System implementation. The VerticalCRS contains currently a single identifier property of string type. Although we currently only support four distinct key values "GEOID", "ELLIPSOID", "NAVD88" and "NGVD29" we expect to support a broader set in the future including, eventually, user defined vertical CRS which will require additional parameters to be added. Implements VerticalCRSProps Methods Name Description constructor(data?: VerticalCRSProps): VerticalCRS equals(other: VerticalCRS): boolean Compares two vertical CRS. toJSON(): VerticalCRSProps Creates a JSON from the Vertical CRS definition fromJSON(data: VerticalCRSProps): VerticalCRS Static Creates a Vertical CRS from JSON representation. Properties Name Type Description id Readonly "GEOID" | "ELLIPSOID" | "NGVD29" | "NAVD88" Vertical CRS Key name. Defined in core/common/src/geometry/CoordinateReferenceSystem.ts Line 298 Last Updated: 11 June, 2024