VERTCRS["ITRF_1993",
    VDATUM["D_ITRF_1993"],
    CS[vertical,1],
        AXIS["ellipsoidal height (h)",up,
            LENGTHUNIT["metre",1]],
    USAGE[
        SCOPE["Not known."],
        AREA["World."],
        BBOX[-90,-180,90,180]],
    ID["ESRI",115734]]