[wellylug] Possible project of interest? (LINZ vector topo data)

Brent Wood pcreso at pcreso.com
Thu Dec 16 22:00:23 NZDT 2004


Re a freely distributable copy of the NZ vector topo data from LINZ.

--- Donald Gordon <don at dis.org.nz> wrote:

> Hi
> 
> Did anything end up happening with that project?  I've occasionally 
> thought that having such data would be useful for various projects but 
> been put off by the cost of getting it from LINZ. I could probably 
> write a converter if no one else has yet.


There were a few developers interested, but nothing eventuated. Kim Ollivier
(www.ollivier.co.nz, www.ollivier.co.nz/product/index.shtm) has developed a
cheap but freely redistributable dataset, though he is not making his code
available. His "Corax" topo dataset based on the 2001 LINZ data I provided is
available relatively cheaply directly from him, but can be freely
redistributed. The current version of the LINZ vector topo dataset is also
available from him, tho at a price & not re-distributable. (The price is still
much better than the other commercial sources). He also has other datasets
available relatively cheaply.

I have reprojected his 2001 NZMG dataset to lat/long, but used the 7 element
conversion rather than the LINZ distortion grid, so errors of up to 5m may be
introduced at some places... one of these days (months) I'll do it properly :-)

For my purposes a potential error of up to 5m in a few locations wasn't an
issue.

I've also prototyped a script which builds a 670Mb geotiff of NZ as a raster
background. See the following for an example of a geotiff derived from the
vector data overlaid with roads/rivers/rail vectors. All done with Open Source
software :-) It is unprojected lat/long so looks slightly distorted, but should
be enough to give you an idea...
 
http://203.79.92.204/cgi-bin/mapserv?map=/srv/www/htdocs/topo/wgtn1/wgtn.map&mode=map


The NZ GPS users society is interested, & has set up www.gis.org.nz, (in
addition to www.gps.org.nz) to facilitate code & data sharing. 

Also see http://gwprojects.orcon.net.nz/gps/ for a gps mapping project using
the data.


Now to look at the National Road Centreline Database & Land Cover Database :-) 






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