[Talk-ca] Geobase NRN import script

James Ewen ve6srv at gmail.com
Fri Jan 2 00:00:30 GMT 2009

On Thu, Jan 1, 2009 at 4:17 PM, Jason Reid
<osm at bowvalleytechnologies.com> wrote:

> The script will generate a single OSM file per GML file, so 1 per
> province currently.

Any plans on how to merge the OSM and GeoBase files into one database?

> The mapping between the Geobase tags and OSM tags is a work in progress
> still, it roughly follows whats on the wiki, both on the geobase import
> and the Canadian tagging guidelines. This is the largest area of the
> script that needs refinement yet.

I think this is going to be the single biggest problem once we have
the database merged. Do we stick with what GeoBase has the roads
tagged as, or do we change the tags to meet what the OSM descriptions
are? I see in the script that you are going to be overriding the
GeoBase tags simply based on highway numbers.

 # Primary (5-100)
              if ref >= 5 and ref <= 100:
                self.tags['highway'] = 'primary'

# Secondary (500-899, 901, 940)
              if ref >= 500 and ref < 900:
                self.tags['highway'] = 'secondary'

 # Tag Transcanada/Yellowhead as trunk
              if ref == 1 or ref == 2 or ref == 3 or ref == 4 or ref
== 16 or ref == 35 or ref == 43 or ref == 49 or ref == 201 or ref ==
                self.tags['highway'] = 'trunk'

Portions of Highways 2 and 16 near Edmonton meet the description of
Motorway. If we change the attribute to reflect the fact that the
highway is a restricted access major highway with access ramps, how is
that going to affect future update imports?

I've looked at the NRN, and seen discrepancies between what is in the
database, and what exists on the face of the earth. It's going to be
interesting to see how much the GeoBase database gets modified by OSM
users to fit their idea of what's out there.

That being said, I don't think this should stop the progress being made.

> You can see some of the initial converted data rendered on the map at
> http://openstreetmap.ca/map/. This map will be updated periodically as
> things progress, as a test bed to make sure that things are working. So
> not all provinces are there yet.

What I see looks good! I've poked around southwestern Manitoba
checking out the area where my Dad grew up, and can identify the towns
just by the highway grid, and the roads in town. Add in hydrography,
some railway and placenames and it's starting to look like a real map
that you'd have to pay money for! The road import is looking really
good. I can't see the attribute tags on that site, but it's a visual
treat to see all that data.

Can you slice the GML file up into chunks? We could manually start the
import process by manually defining areas where we want to start
importing data. Areas chosen by users with little or no existing data.


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