id,summary,reporter,owner,description,type,status,priority,milestone,component,version,resolution,keywords,cc 1,New Zealand Map Grid transformation,ironss,madair,"Attached are three files implementing a proj4js projection for New Zealand Map Grid. * nzmg.js - implementation of the transformation algorithm * EPSG27200.js - definition for EPSG:27200 (NZMG) * EPSG4272.js - definition for EPSG:4272 (NZGD49) Copyright is in my name, but I am happy to pass that on to OSGeo if necessary. Just ask. Licensed under GPL v3, but once again, I am happy to discuss a different license. Please review this code and pass any feedback on what would need doing to incorporate it into the proj4js repository. Thank you Stephen Irons Background New Zealand Map Grid (NZMG) is a projection used to convert latitude and longitude to easting and northing coordinates in metres. It was designed to minimize the scale error over the land area of New Zealand and cannot be used elsewhere. The New Zealand govnernment survey agency, LINZ (Land Information New Zealand) has published two series of maps covering the mainland areas of New Zealand. * 262-series is 1:250000 * 260-series is 1:50000 These maps are available in printed form and are currently the only large-scale maps of New Zealand widely available to the general public. Vector data is also available. Various commercial concerns have scanned these maps, or generated tiles from the vector data, and released products using these tiles. I have one of these products and want to use the tiles with OpenLayers. New Zealand Map Grid New Zealand Map Grid was designed by Dr W. I. Reilly in 1973. Its official specification is published as New Zealand Map Grid, Department of Lands and Survey Technical Circular 1973/32. A scanned image of the publication is available at http://www.linz.govt.nz/docs/miscellaneous/nz-map-definition.pdf It is also described in Conversion between Latitude and Longitude and New Zealand Map Grid, OSG Technical Report 4.1, 1998. This document is available at http://www.linz.govt.nz/docs/miscellaneous/nzmg.pdf NZMG is given EPSG code EPSG:27200. It is defined at http://spatialreference.org/ref/epsg/27200/proj4/ as * ""+proj=nzmg +lat_0=-41 +lon_0=173 +x_0=2510000 +y_0=6023150 +ellps=intl +datum=nzgd49 +units=m +no_defs"" Now, most of this is known to Proj4js code. However, the projections 'nzmg' is not know, and needs to be implemented. ",defect,closed,major,future,core,,fixed,,