[Talk-us] Fixing shorelines

[Eric H. Christensen]

On Thu, Dec 13, 2012 at 02:23:52PM -0500, Phil! Gold wrote:
> * Eric H. Christensen <eric at christensenplace.us> [2012-12-11 21:24 -0500]:
> > Is there a good way to make the PGS-sourced data match the Tiger data in certain areas to improve the accuracy?
> 
> If you use JOSM, the ContourMerge plugin is very helpful here.  You can
> select nodes on each of the TIGER and PGS ways near where they diverge
> from each other and then drag the coastline onto the administrative
> boundary.  Be aware that both the TIGER and PGS imports periodically split
> ways to keep them from getting too long, so you might have to do the
> merging in several places along the full length of the overlap.

Thanks for the advice.  I've tried that technique and it seems to have done what I wanted but I'm withholding judgment until I actually see the results on the website.

> Even the TIGER data isn't perfect (though it's far better than PGS, at
> least in Maryland), so what I like to do it use the JOSM
> ImproveWayAccuracy plugin to align the administrative boundary to aerial
> imagery and then use the ContourMerge plugin to overlap the coastline
> ways.  If there's no administrative boundary, I just use the
> ImproveWayAccuracy plugin on the coastline ways directly.

Another great tool.

> On a side note, Anne Arundel County is kind enough to put their geodata
> into the public domain, plus they've got an ArcGIS REST server at
> http://gis-world.aacounty.org/ArcGIS/rest/services/ .  I find their
> basemap, parcel, and orthoimagery layers to be very useful (although JOSM
> can't use them directly, as far as I know; I use tilestache to go between
> JOSM's tile underlays and the ArcGIS REST interface).

I haven't seen that data before but will have to take a look at what's there.  I've not been very impressed by the TIGER roadway data in my little town so I've been slowly making changes or verification that the data is correct.  I just moved here so I'm just getting started on this project.

-Eric
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