Paul Norman wrote: Address interpolation indicating roads where there are no roads is an interesting one, and might be suitable to a QA tool.
Just recall that there are two issues with this one. .. - Imports of addresses data have been done without importing corresponding roads (there are roads on the ground but not in OSM); - Some addresses data are wrong - then there are no roads associated to them Daniel -----Original Message----- From: Paul Norman [mailto:penor...@mac.com] Sent: June-18-15 17:15 To: talk-ca@openstreetmap.org Subject: Re: [Talk-ca] OSM data quality in Canada On 6/17/2015 1:12 PM, Martijn van Exel wrote: > * What is the imports history, particularly in relation to road > network, POIs and addresses? (Beyond what’s in the import catalogue > page on the wiki, if anything) CanVec, National Hydrographic Network (NHN), and National Road Network (NRN), all out of Natural Resources Canada (NRCan). CanVec is a product supplied in .osm format composed of multiple government datasources, including the NHN and NRN. The sources used vary by region, so what is true somewhere may not be true elsewhere. > * What external (government and otherwise) open geospatial data sources are > out there that have been or may be considered for improving OSM? There is probably an equivalent to TIGER address ranges that should be used by a geocoder as a fallback in the same manner. I'm not aware of anything really under consideration. Data released by the federal government under their OGL variant is okay license-wise, but the same is not always true for the provincial and municipal data. > * Are there any Canada-specific mapping and tagging conventions? Because roads are largely the responsibility of provinces, road classification varies province by province. > * Are there any known big (national) issues in the Canadian OSM data? > (misguided imports / bots, major tagging disputes, that kind of thing) CanVec has left parts of the country a colossal mess. I would say the forest/water data is the worst, often coming from different sources from the 70s, and these sources often do not agree with each other. When faced with 40 year old imported landcover data that doesn't resemble reality, the best option is often to just delete it. There are some regional quirks with CanVec. These include - Poor alignment of water or trees with each other - Forests on what are now residential areas - Incorrect surface or lanes values - Invalid housenumbers (-1) - Interpolation used for what should be a single number - Interpolation where there aren't roads in the data - Extra spaces in some road names - Unclassified roads tagged as residential NRN and NHN were less wildly imported. Not having landcover, they don't have those problems, but do have some of their own - Incorrect surface or lanes values (NRN) - Lots of tag cruft (Both) - Badly overnoded streams (NHN) - Streams with oneway (NHN) - Non-standard tagging (NHN) > * Which (other) companies / organizations / government agencies use OSM data > for Canada? NRCan used to use CanVec and OSM matching to find locations missing in their dataset, but I'm not sure if they do this anymore. > * Any suggestions for QA tools that would help the community, either existing > or new? Beyond the standard international ones, I'm not sure. The incorrect surface, lanes, housenumbers, and extra spaces are probably all amenable to a mechanical edit rather than a QA tool. Some headway has been made with mechanical edits. The tag cruft will remove itself over time as people edit the objects. Overlapping water/trees from CanVec are so easy to find, and I'm not sure a QA tool is the best choice where the time to fix hugely outweighs the time to find. Address interpolation indicating roads where there are no roads is an interesting one, and might be suitable to a QA tool. _______________________________________________ Talk-ca mailing list Talk-ca@openstreetmap.org https://lists.openstreetmap.org/listinfo/talk-ca _______________________________________________ Talk-ca mailing list Talk-ca@openstreetmap.org https://lists.openstreetmap.org/listinfo/talk-ca
