metre
EPSG
OGP
2007-10-29
up
W
3..
Used in topocentric coordinate-systems related geometrically to the ellipsoid, as opposed to those that are gravity-related. If the topocentric origin is on the ellipsoid surface, topocentric height = ellipsoidal height.
Vertical axis of a Cartesian 3D CS which is perpendicular to the ellipsoid and passes through the topocentric origin. Positive is up at the topocentric origin.