This dataset provides information about the position, height, height datum, height accuracy, mark name, mark type, condition and unique four letter identifier for geodetic marks that have an authoritative height in terms of a vertical datum. Heights are in datums defined at http://www.linz.govt.nz/geodetic/datums-projections-heights/vertical-datums/.

All marks will have positions in terms a 3D New Zealand official geodetic datum. The horizontal positions of marks are provided for approximate location purposes only .

This dataset only contains marks that are within the New Zealand mainland and offshore islands. The height data for these marks have been generated using precise levelling from datum tide gauges, or has been acquired by 3rd party sources either as levelling observations or direct heights.

The source data is from Land Information New Zealand's (LINZ) Landonline system where it is used by Land Surveyors. This dataset is updated daily to reflect changes made in the Landonline.

Accuracy

The accuracy of normal-orthometric heights are described by height orders.

For more information see http://www.linz.govt.nz/geodetic/datums-projections-heights/heights/height-orders/.

Note the accuracy applies at the time the mark was last surveyed - see the geodetic database for historical information about height coordinates.