Height Conversions

There are two types of height available in New Zealand. Precise leveling-derived mean sea level (MSL) normal-orthometric heights and GNSS derived ellipsoidal heights.

These heights relate to different surfaces, normal-orthometric heights to the quasigeoid and ellipsoidal heights to the ellipsoid. Furthermore the normal-orthometric heights are in terms of 13 separate datums that are offset from the quasigeoid.

Heights can be converted between systems if the quasigeoid height (eg NZGeoid05) at the location is known and also the offset for the datum that the normal-orthometric height is in terms of (see figure below).

Ellipsoidal to mean sea level (normal-orthometric heights) conversion

Formulae and descriptions for converting NZGD2000 or WGS84 ellipsoidal heights to or from MSL datums. This conversion uses the NZGeoid05 geoid model. more...

Converting between mean sea level datums

Formulae and description for converting heights between MSL datums. more...

Height transformation examples

Examples of the transformation of heights between different datums and systems.more...