Hi,
It seems that the UK administrative boundaries in OSM are rather
incomplete. I'm looking for advice about the possibility of doing a bulk
upload of the OS BoundaryLine data for counties, districts and unitaries.
I have conquered the projection issues with the downloaded shapefiles
and I can now produce GPX files from the OS data, which look good to my
eye in Google Earth and Potlatch, aligning very neatly to the natural
boundary features. To do this I have written a program in VB.NET which
uses MapWindow GIS for the shapefile loading and the reprojection. It's
not fully ready yet - I still need to add the metadata to the tracks
from the shape attributes.
My questions to the community:
1) Would a bulk upload of any or all of this data be interesting?
2) As I have no experience of performing bulk uploads myself, how would
that actually work? Is GPX a good starting point, or should I be looking
to produce .osm format?
3) This data is very verbose (lots and lots of points). To what extent
should simplification be considered, using Douglas-Puecker or similar?
I can make a big GPX available (about 300MB), or a GPX per admin unit.
Then they will need uploading as traces, converting to ways, splitting
into parts and recombining into relations. At present each "entity" is a
polygon (actually a GPX track which ends where it started). Should I
consider identifying common boundaries and splitting the polygon into
parts and making the "entities" into relations? Obviously this won't
work with GPX format, so .osm would be required for this. There are many
"entities" with enclaves/exclaves so these would require multipolygon
relations. I have not looked at how these turn out in the GPX. I
probably need to watch for the direction (clockwise/anticlockwise).
Would anybody have any advice about how I could take this further?
Regards,
Colin
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