VERT_CS["ITRF_1991",
    VERT_DATUM["D_ITRF_1991",2002,
        AUTHORITY["ESRI","from_geogdatum_EPSG_6650"]],
    UNIT["metre",1,
        AUTHORITY["EPSG","9001"]],
    AXIS["Ellipsoidal height",UP],
    AUTHORITY["ESRI","115732"]]