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Pre-2010 normal-orthometric height orders

Before May 2010, normal-orthometric heights were categorised using orders based on observation method and survey significance. This order framework was replaced by the Standard for the Geospatial Accuracy Framework (LINZS25005) and Standard for Tiers, Classes and Orders of LINZ Data (LINZS25006), and has been adopted for New Zealand Vertical Datum 2016. The old framework continues to be used for the existing local vertical datum.

Find out about current height orders used with New Zealand Vertical Datum 2016 (NZVD2016).

Height orders

New Zealand Vertical Datum 2016

Normal-orthometric heights in terms of the 13 mean sea level vertical datums are classified into orders according to the way they were observed.

Local mean sea level datums

This Order scheme was replaced when the Standard for the Geospatial Accuracy Framework (LINZS25005) and Standard for Tiers, Classes and Orders of LINZ Data (LINZS25006) came into effect May 2010. It has also been adopted for New Zealand Vertical Datum 2016 (NZVD2016).

Standard for the Geospatial Accuracy Framework

Standard for Tiers, Classes, and Orders of LINZ Data

OrderDescription
1First and second order precise levelling carried out to full precise level specifications on stations constructed to acceptable benchmark standards. The maximum closure error is ±2mm√k, where k is the distance in kilometres.
2Third order spirit-levelling with a maximum closure error of ±7mm√k, where k is the distance in kilometres; precise levelling of marks not constructed to acceptable bench mark standards; simultaneous reciprocal trigonometric levelling over short lines provided origin has a 1st or 2nd order height.
3Less accurate levelling than above provided the origin has a 1st, 2nd or 3rd order height; systematically adjusted trigonometric levelling with good adjustment corrections and reliable fixed heights.
4Conventional systematically adjusted trigonometric levelling with poor adjustment corrections, weak fixes, long lines or hanging line connection.
5Station height of unknown reliability or doubtful accuracy.
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