[GRASSLIST:2173] Re: Large scale data from US Census
rshepard at appl-ecosys.com
Thu Jul 26 18:05:30 EDT 2001
On Thu, 26 Jul 2001, William A. Perkins wrote:
> I have gotten TIGER files into GRASS. v.in.tig.basic and v.in.tig.lnmk
> (check spelling) still seem to work for up to 1999 TIGER files (but I
> read somewhere that they did not work for 2000, which I have not
I remember reading this, too.
> I warn you though, do not expect the TIGER data to be "high resolution" --
> at least in the eastern Washington counties I've worked with they are not.
> I believe that most of the TIGER layers are based on the USGS 1:100k DLG's
> anyway, and even then something got lost in the conversion.
Oh. I didn't realize this. I've not worked with TIGER files before.
> TIGER files also have trouble matching up with anything else because
> the Bureau pays no attention to the horizontal datum in their original
> data (and they admit this in their documents).
Ouch! No wonder the census counts are off by so many people.
> I would go with whatever USGS 1:24k SDTS data sets are available.
Dr. Richard B. Shepard, President
Applied Ecosystem Services, Inc. (TM)
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