I've got a set of data that is referenced to NZ TOPO50 locations. I've been trying to work out how to convert them to something useful like WGS84 lat/lon.
I have gone through the documentation at http://www.linz.govt.nz and am still stuck.
An example is "BA32 582206" becomes "36 50 50S 174 46 28E". I have found the NZ-topo-50-map-sheets.xls that has a 5 point mulitpolygon to describe BAS32, but I can not work out how the 58/2 and 20/6 become 174 46 28E and 36 50 50S respectively.
Use the online tool at http://apps.linz.govt.nz/coordinate-conversion/index.aspx
choose as input coordinates system "New Zealand Transverse Mercator Projection" and as output coordniate system "World Geodetic System 1984"
Your input coordinates should be something like
5413457 North 1528677 East
Than you get your WGS84 Coordinates.