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

[Pete Black]

Brent,

Just out of interest, how hard would it be to produce a detailed 
topographic 'height field' of the wellington region e.g. where each 
pixel's height above sea-level is encoded as a 16 or 32-bit 'grayscale' 
value, as opposed to the false-colour shading you have in your example 
image?

Thanks

-Pete

>Re a freely distributable copy of the NZ vector topo data from LINZ.
>
>--- Donald Gordon <don at dis.org.nz> wrote:
>
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>>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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