[Freegis-list] Reading VMAP data

[Frank Warmerdam]

Oliver White wrote:
> Could anyone help with a question about data conversions?  
> 
> We have a set of VMAP data CDs (the National Imagery and Mapping Agency product),
> and I'm trying to extract the roads data in some usable format, such as vertex
> lists.
> 
> Is there a Free Software program which might be able to do this?  I've tried NIMA's
> own (discontinued, unsupported) program NIMAUSE, and it failed to read the data, 
> complaining that the data was designed for the Solaris version of the program.  Even 
> if this were to work, I believe that it's only a viewer, rather than a converter.
> NIMA reccommend various Non-Free tools, which is not a useful solution.
> 
> NIMA's web-page on the format seems to be unavailable, and VTerrain's notes on
> the format have the warning "Don't try to read VPF unless absolutely necessary. 
> It's a dog of a format". Looking at the directory structure itself shows many 
> thousands of data files, most of them in some sort of binary format.
> 
> I will soon have GRASS available, although I've not used it before, and the GRASS
> website doesn't list VMAP as a vector input format.  Are there any other Free or GPL tools
> which can read such data?  Has anyone successfully converted or imported VMAP into
> their data sets, who can say what steps are required?

Oliver,

The OGDI library and tools includes pretty good VPF/VMAP support.  You
can use the ogdi_import utility distribute with it to convert data to a
shapefile.  Also, OGR supports OGDI so you can use OGR enabled applications
to access VMAP via OGR (such as GRASS, OpenEV, the OGR PostGIS loader,
VTerrain and MapServer).

   http://ogdi.sf.net/

The OpenEV_FW kit includes OGDI support built in.

   http://gdal.maptools.org/dl/openev/OpenEV_FW_163.zip

However, the VPF driver isn't very well documented so it can be pretty hard
to figure out how to use it.   For VMAP0 worldwide data an access url for
the eurasian CD mounted on /mnt/cdrom might look something like:

   gltp:/vrf/mnt/cdrom/v0eur/vmaplv0/eurnasia

OGDI is somewhat sensitive to the naming convension (upper/lower case, and
whether trailing periods are added) used to mount VPF data if done from CD.
As mentioned on the VTerrain site, performance for reading VPF isn't
necessarily all that great so you might want to look at extracting what you
want to a more malliable format.

Good luck,

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