[Talk-us] tiger county boundaries (was:Re: Characterizing Systematic Errors in Hawaii and US Pacific Island Data)

Apollinaris Schoell aschoell at gmail.com
Sat Oct 3 05:54:37 BST 2009


On 2 Oct 2009, at 21:32 , Kevin wrote:

> yes, we can import a subset of the tiger data and it's easy to  
> reproject
> to wgs80.  fyi, 2009 tiger is available.  i can import the county
> boundaries for hawaii right now since the it looks like the usgs  
> county
> boundaries weren't imported.
>
> the problem will arise on the mainland where people have edited the
> county boundaries with relations and what not.  there are no state
> boundaries in tiger and the current state boundaries is osm are in
> relations, but i see where some state boundaries are not in a relation
> with the county boundaries, shouldn't they be?  some usgs county
> boundaries that are also state boundaries are way off from the  
> imported
> state boundaries.  not sure where those state boundaries came from.
> seems like we can do alot of clean up and remove duplicate ways for  
> the
> same boundary if we import the tiger counties.  maybe i can begin to
> import on a state-by-state basis checking for edits and relations.  i
> can start a wiki for the import.  sound good?  suggestions?
>

let's do some analysis on the quality first. California has official  
county borders. they don't align with the existing Tiger county/city  
borders. Tiger data is very low quality and doesn't align at all with  
Topo 24k. Also where borders can be easily matched to features on  
ground in Yahoo  it's obviously wrong. If tiger 2009 is really high  
quality then we should import it. And this time do it clean without  
overlaps, relations for each county, align with state borders ....



> kevin
>





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