[Talk-ca] RIP CanVec

[Dan Charrois]

> On 2014-Nov-17, at 1:53 PM, Ga Delap <gadelap at gmail.com> wrote:
> 
> Il y a actuellement un peu de bruit sur talk.ca pour faire renaître les
> importations CanVec.
> Il ne faut pas.
> 

Unfortunately, though I can read French, I can only speak or write English properly, but wanted to weigh in on this discussion.

As someone who has imported a fair bit of Canvec data, I wanted to weigh in on this.

Though Canvec data has some issues involved in importing into OSM that people should be aware of, I think that it does far more good than harm if treated properly.  All data from Canvec (or any source for that matter) should be inspected carefully before importing into OSM - using satellite imagery for verification, for instance.  And in particular, any data from Canvec that is replacing existing data in OSM should be considered very carefully and with a high degree of suspicion, as in most cases (though not all), our existing OSM data is superior.

But with that said, there are a lot of pieces of data from Canvec that we don't have in OSM and should be added - more streets, addresses, and forest areas, as you mentioned - especially if they're verified by overlaying satellite imagery.  I'd add to that list hydrography.  In particular, smaller streams and lakes in my part of Canada tend not to exist at all in OSM, and adding them from Canvec adds data where there otherwise was none.  It's usually best to leave the larger lakes and rivers that already exist alone, though perhaps adding a bit more detail to their shorelines.

In my experience, probably about 90% of the data in Canvec (particularly non man-made features) that is not already in OSM may be worth importing.  And similarly, about 90% of the data that is common between the two is best left alone.

Some areas of the map in more remote areas don't have any data at all in OSM - in those cases, importing Canvec data particularly adds a huge amount of value.  In places like downtown Toronto, probably not so much.  I think Canvec data is very valuable for OSM and very strongly support its continued importation, under the condition that whomever is doing it knows some of the issues as you pointed out to ensure they are always making things better instead of worse.

Dan
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Dan Charrois
President, Syzygy Research & Technology
Phone: 780-961-2213