[GRASSLIST:2172] Re: Large scale data from US Census

[William A. Perkins]

>>>>> "Rich" == Rich Shepard <rshepard at appl-ecosys.com> writes:

    Rich> Has anyone here used TIGER files to get 1:24,000 scale data
    Rich> on roads and hydrography into GRASS? I don't need census
    Rich> blocks or zip code boundaries, but I'd sure like
    Rich> higher-resolution transportation and hydrography than I get
    Rich> with the 1:100K files that are readily available.

    Rich> Thanks,

    Rich> Rich

    Rich> Dr. Richard B. Shepard, President

    Rich>                        Applied Ecosystem Services, Inc. (TM)
    Rich>             2404 SW 22nd Street | Troutdale, OR 97060-1247 | U.S.A.
    Rich>  + 1 503-667-4517 (voice) | + 1 503-667-8863 (fax) | rshepard at appl-ecosys.com
    Rich>                  Making environmentally-responsible mining happen.


Rich,

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
tried).  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.

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).

I would go with whatever USGS 1:24k SDTS data sets are available.

Bill


-- 
Bill Perkins
Pacific Northwest National Laboratory
Environmental Technologies Division, Hydrology Group
P.O. Box 999 MSIN K9-36
Richland, Washington, USA  99352
voice: (509) 372-6131 fax: (509) 372-6089 email: wa_perkins at pnl.gov