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I have downloaded the OSM from OpenStreeMap that came with all nodes from the map and their respective coordinates. Now I have to plot a node (latitude and longitude) on Google Maps, but all coordinates end up in different places than they should.

To illustrate I'll show the node -12.92122,-38.34991 (lat,long) on OpenStreetMap and Google Maps, as you can see on screenshots:

OpenStreetMap http://i.stack.imgur.com/9Ac7R.png

Google Maps http://i.stack.imgur.com/Szyot.png

My question is how can I adjust these values.. so I can plot the node on google maps at the same place of openStreetMap. Google Earth uses WGS-84 coordinates, expressed in decimal degrees, and OSM uses WSG-84 as well.

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Have you tried to overlay the two datasets to see if they are coincident? You may be seeing that the points are the same location but that the geometry you are wanting to be matched against actually have a different location in space. –  D.E.Wright Oct 24 '12 at 17:25
    
@D.E.Wright thanks for your reply.. I have verified different nodes and all of them have a different position on map (few meters of distance). It impacts on route because some points goes too near from another street then the google maps is considering the second street instead of the correct one, resulting in some big routes to places that are actually near. So that is why I don't believe that it is a problem with geometry location. –  Roberto Ferraz Oct 24 '12 at 17:52
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1 Answer 1

up vote 2 down vote accepted

It is not possible to adjust for this because these are two completely different datasets. There is no projection or anything that will convert one into the other. Openstreetmap data is (mostly) acquired by volunteers with GPS devices or people tracing aerial imagery. Both types of data acquisition are not very precise and will have a few meters error at least.

By the way: I wouldn't trust Google data to be of much better accuracy either.

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Humm Thanks @Moe, actually I am not trusting on google, it is just a requirement to plot the data on google maps.. but unfortunately this data came from OpenStreetMap and as you said it is not possible to convert one in the other.. I will consider to use the openstreetmap layer too instead of google maps.. thank you! –  Roberto Ferraz Oct 25 '12 at 13:15
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