[OSM-dev] islands and coastlines misaligned

Ian Dees ian.dees at gmail.com
Thu Aug 14 20:15:33 BST 2008


I imported the county borders from the National Atlas site shapefiles. I
tested a few counties before uploading them and didn't see this big of a
difference. I suggest manually adjusting them for now.

On Thu, Aug 14, 2008 at 2:00 PM, Jon Burgess <jburgess777 at googlemail.com>wrote:

>
> If you turn on the data layer it shows that the rendered tiles match the
> underlying data in the OSM DB so it isn't an issue with the rendering.
> The coastlines appear to be consistent with the tiger import and the
> Yahoo imagery. It looks like the county data is at fault.
>
> It seems the county data came from:
> http://www-atlas.usgs.gov/mld/countyp.html
>
> It looks like the points in the DB match the shapefile. The data
> projection data they specify (NAD83/GRS80) seems to be an exact match
> for WGS84.
>
> The error seems to be a shift of around 500m. The FAQ for the county
> data has a section for data accuracy but the answer is blank.
>
>
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