By Samat Jain
November 30, 2010 - 3:59pm
Microsoft’s Bing aerial imagery (that’s recently been donated to OSM for use in tracing) is offset by a few meters in some places.
For example, earlier this week I traced buildings with imagery from USDA’s NAIP program. Besides a history of being well-rectified, a GPS track in the parking lot confirms that I was spot on. However, on Bing with a low zoom, they’re misaligned:
Zoom in a bit, and they magically align again:
Apparently, different, well-rectified imagery is used at higher zooms. If I’ve found one problem, it then follows that it exists elsewhere. Be careful when tracing!
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Comments
Permalink Jean-Marc Liotier on December 1, 2010 - 7:51am wrote…
Thank you for the warning - I tested Potlach 2 and the Bing imagery yesterday, and I realigned a couple of streets based on the Bing imagery… If you are right, that might have been a misguided move. I’ll see how it correlates with GPS and other sources.
You might want to take that to the talk@osm mailing list for more feedback.
Permalink Anonymous Visitor on December 1, 2010 - 3:58pm wrote…
I used to align objects (surveyed during the day) accordingly to Yahoo satellite. Now I’m going to redo them with Bing’s highest zoom. When zooming out, Bing is well aligned in my region with both Yahoo and practically all existing roads and points. When zooming in, I can make the objects more detailed.
Thanks to Bing for allowing to use its satellite imagery… It doesn’t know what to do with the imagery, that’s why it has to share it with others.
Permalink Anonymous Visitor on December 5, 2010 - 3:22am wrote…
J’ai verifié en France sur les certaines zones côtières entre BING et GEOLITTORAL ou le CADASTRE. L’écart est confirmé.
GEOLITTORAL+CADASTRE=YES mais BING+CADASTRE=NO
Permalink Samat Jain on December 5, 2010 - 5:51am wrote…