The New Zealand map grid is a conformal map projection specifically designed for large-scale mapping of New Zealand. The projection method uses the Cauchy-Riemann equation of complex arithmetic and is centered at 173° east and 41° south.
The New Zealand map grid projection was designed by W. I. Reilly in 1973. It is available in ArcGIS Pro 1.0 and later and in ArcGIS Desktop 8.1.0 and later.
The subsections below describe the New Zealand Map Grid projection properties.
New Zealand Map Grid is a modified cylindric projection. All the meridians and parallels project as sixth-order complex-algebra polynomial curves.
New Zealand Map Grid is a conformal map projection. Directions, angles, and shapes are maintained at an infinitesimal scale. Area distortion is less than 0.04 percent and scale is within 0.02 percent of true scale for the New Zealand region.
The use of this projection is limited to very large-scale maps in New Zealand. It is not advisable to use the projection elsewhere.
The projection is limited to a small area around the center of the map.
New Zealand Map Grid parameters are as follows:
- False Easting
- False Northing
- Longitude Of Origin
- Latitude Of Origin
Office of the Surveyor-General (1998). Conversion between Latitude and Longitude and New Zealand Map Grid. OSG Technical Report 4.1. Wellington: Office of the Surveyor-General Land Information New Zealand.
Reilly, W. I. (1973). "A conformal mapping projection with minimum scale error." Survey Review, 22 (168), p. 57-71. DOI: 10.1179/sre.1918.104.22.168
Stirling, I. F. (1973). New Zealand Map Grid. Department of Lands and Survey Technical Circular 1973/32. Wellington: Office of the Surveyor-General Land Information New Zealand.