We’re improving over 80,000 coordinates on geodetic marks at the end of June 2016.

This means that observations you make between geodetic marks will agree much better with coordinates in the Geodetic Database, especially when observing between the PositioNZ network of continuous GNSS stations and other geodetic marks.

To make this improvement, almost all geodetic data has been combined in a single least squares adjustment process for the first time. This has enabled a number of improvements to the coordinate calculation process to be implemented. For example, the latest version of the deformation model has been applied and additional high-quality GNSS data collected by GNS Science and the University of Otago has been included.

Coordinates will also be updated to account for the impacts of the 2013 Cook Strait and Lake Grassmere earthquakes, as well as the 14 February 2016 Christchurch earthquake.

These bullet points apply to LINZ’s existing Order 1-5 geodetic coordinates.

  • 95% of horizontal coordinate changes less than 0.04m (99% are less than 0.07m)
  • 95% of vertical coordinate changes less than 0.09m (99% are less than 0.14m)
  • 95% of horizontal coordinates have an uncertainty (95% confidence interval) better than 0.02m, relative to the PositioNZ network
  • 95% of vertical coordinates have an uncertainty (95% confidence interval) better than 0.03m, relative to the PositioNZ network 

If you already have a surveying project underway when the change is made, there’s no need to switch to using the new coordinates (unless it would benefit the project to do so). The current coordinates will still be available in the Geodetic Database by following the “Historical values” hyperlink.

Download a map showing the national coordinate change spatially, both horizontally and vertically (PDF 1MB).

More details about the coordinate update will be shared on this page. 

Last Updated: 29 June 2016