I wish they'd updated the Bing high resolution images.... In Orangeville there's a new mall, but only one image (of three tiles) has the new mall, the other has the cleared field from when they started. I can only put in half the buildings.
Any ideas on how often they update the high res? On Fri, Sep 2, 2011 at 3:08 PM, Andrew MacKinnon <[email protected]>wrote: > On Thu, Sep 1, 2011 at 11:15 PM, James A. Treacy <[email protected]> > wrote: > > On Thu, Sep 01, 2011 at 10:30:34PM -0400, Andrew MacKinnon wrote: > >> Given that this sort of work is time consuming it will take a while to > >> finish. However, 99% of the work that requires importing coastlines > >> from CanVec is done, and realigning coastlines using Bing is a lot > >> less disruptive and less error-prone. > > > > I'm curious why you would trust the Bing imagery more than canvec. In > > addition to not being very high resolution, I would think that Bing > > would suffer from problems with registration (alignment of images to > > lat/lon) which would have to be checked against ground readings. Of > > course canvec should also be checked for accuracy with local readings. > > > > Further, my understanding is that much of the canvec data is generated > > from local surveying, which uses high end GPS which are extremely > > accurate. > > > > Locally (Kitchener-Waterloo) I have found that the canvec data is very > > accurate and most imagery less so. > > I have been using the Bing imagery where high resolution imagery is > available and Canvec where high resolution Bing imagery is not > available. My impression is that for coastlines, tracing from Bing > imagery is more accurate than the Canvec data. > > Keep in mind that some of the Canvec data is VERY out of date. While > the road data in Canvec is fairly up to date, the rest of the Canvec > data seems to be old (1990s, 1980s even?) Canvec data shows woods, > buildings etc. which clearly haven't existed for many years, for > example it often shows forests in areas where new subdivisions have > been built recently, old industrial buildings which were torn down 10 > years ago and replaced with housing, long-ago abandoned rail spurs to > industrial areas and long-demolished agricultural buildings. I would > not trust anything except the roads layer in Canvec to be up to date. > > _______________________________________________ > Talk-ca mailing list > [email protected] > http://lists.openstreetmap.org/listinfo/talk-ca >
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