[OSM-talk] GeoBase nodes import

Frederik Ramm frederik at remote.org
Thu Dec 18 15:32:13 GMT 2008


Hi,

Sam Vekemans wrote:
> And so, im not sure that the local are mappers would want to have a manual
> merge (wiping out what they did, importing all the roads, then slowely
> bringing back the OSM roads if any are needed)
> By having the roads which were not mapped available as nodes to be traced,
> we are not wiping out what the mapper did.

There are many other options you could consider.

For example, we have just received data for all tertiary and bigger 
roads for one of the largest German "Länder", North Rhine-Westphalia. We 
have already got a lot of mapping done in that area; my guess is that of 
the 20.000 km of roads they have given us, probably only about 10% are 
actually still missing in OSM, and another 20-30% can be very 
effectively used to improve existing geometry. (The import is described, 
in German, on 
http://wiki.openstreetmap.org/wiki/Import/Catalogue/Strassen_NRW).

This is not a high-profile project like the GeoBase import is, so we 
wanted to do something with little effort. We settled on loading all 
data into a WMS server which can be accessed through the "OSM Inspector" 
tool (http://tools.geofabrik.de/osmi/?view=strassennrw) or directly as a 
background layer in JOSM so if there are small corrections or omissions, 
people can just trace them off the WMS in JOSM. (It would also be 
relatively easy to provide a tile server with these data in case one 
wanted to have it in Potlatch.)

In addition, for those cases where somebody spots a larger item that is 
missing in our data, we have provided simple .osm files for every 
section of road, and these can be downloaded individually. So if you 
spot a certain road segment on the map and find it's not in OSM yet, you 
can simply download the corresponding .osm file and merge it into JOSM. 
The OSM inspector view will also directly give you the URL for the 
download if you click on an item.

This was relatively easy to set up (partly because we're dealing with 
roads which are fairly uniform compared to a whole set of different 
features).

It would probably not be too difficult to enhance JOSM to auto-download 
such an .osm snippet on request (i.e. click on something in the 
inspector view, then click "add to my running JOSM session" or so), or 
to change the whole system to use data tiles instead of road fragments 
or so. The whole thing is designed to be "computer assisted manual 
import"; there's no automatic import here because our map is simply not 
empty enough for that. - If the situation in Canada is similar then you 
might consider something along these lines. If you have many empty spots 
then maybe you need more automatism though.

Bye
Frederik





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