[OSM-talk] Argh, Canvec imports

Michal Migurski mike at stamen.com
Thu Nov 17 15:54:30 GMT 2011


On Nov 17, 2011, at 6:46 AM, Frank Steggink wrote:

> Quoting Michal Migurski <mike at stamen.com>:
> 
>> A cry of frustration:
>> 
>> I do bimonthly runs of the worldwide coastlines  (http://metro.teczno.com/#coastline), and Canada seems to be a  recurring source of problems. What the heck is going on up there? I  consistently see new imports of what seems to be Canvec data  screwing up coastlines and making for some deeply broken renders:
>> 
>> 	http://mike.teczno.com/img/broken-coast.png
> 
> Hi Michal,
> 
> The rendering error northeast of Quebec City was caused by a novice user who has adjusted the Canvec data which was already there. The import in this region was done by me about half a year ago.
> 
> The user in question had adjusted the coastline tags to waterway=riverbank, in order for him to show it up properly on his GPS (while using mkgmap for the conversion). He already became aware of what he has done, and has fixed the error himself (which I think is laudable). I've done a check, and the coastline looks all right to me. I'm not sure what to do with the remaining waterway=riverbank tag. This is part of a larger discussion about what to do with large waterbodies.
> 
> The slippy map doesn't show the corrected situation yet, because the coastline shapefile is not updated very often.


I had noticed a lot of waterway=riverbank up there, you're right.

The first black and white image I link above is derived from the current, November 10 planet dump, so it's a very recent picture of coastline errors. Many of those errors didn't exist in the coastline I made from the November 3 planet dump.

Here are some sample locations in Canada where the checker has found errors:
	http://www.openstreetmap.org/?lat=58.790035&lon=-94.202604&zoom=17&layers=M
	http://www.openstreetmap.org/?lat=56.749700&lon=-92.698650&zoom=17&layers=M
	http://www.openstreetmap.org/?lat=45.260826&lon=-66.086208&zoom=17&layers=M
	http://www.openstreetmap.org/?lat=45.298267&lon=-66.117219&zoom=17&layers=M
	http://www.openstreetmap.org/?lat=56.970073&lon=-92.627314&zoom=17&layers=M
	http://www.openstreetmap.org/?lat=47.086208&lon=-70.745529&zoom=17&layers=M
	http://www.openstreetmap.org/?lat=57.053591&lon=-92.000000&zoom=17&layers=M
	http://www.openstreetmap.org/?lat=45.238757&lon=-66.055341&zoom=17&layers=M
	http://www.openstreetmap.org/?lat=44.936914&lon=-74.704294&zoom=17&layers=M

-mike.

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michal migurski- mike at stamen.com
                 415.558.1610






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