Path: utzoo!attcan!uunet!cs.utexas.edu!helios!wfsc4.tamu.edu
From: hmueller@wfsc4.tamu.edu (Hal Mueller)
Newsgroups: comp.graphics
Subject: more information on digital maps
Message-ID: <4636@helios.TAMU.EDU>
Date: 21 Mar 90 23:53:26 GMT
Sender: usenet@helios.TAMU.EDU
Organization: Dept. of Wildlife and Fisheries Sciences, Texas A&M University
Lines: 43

I've followed up on some of the information that was posted recently
regarding digital maps.  Here's what I've learned from ESIC (nee NCIC):

There are two types of products available, DEM (digital elevation model)
and DLG (digital line graph).  DEM files are raster based elevations.
DLG files are vector based representation of hydrology, transportation,
political boundaries, and sometimes other information.

DEM is available from EROS Data Center at 1:250 000 scale for the
entire US.  DLG is available from them at 1:2 000 000 scale for the
entire US.

For some areas of the country finer resolution data is available.  DLG
exists at 1:100 000 scale.  DLG and DEM exist at 1:24 000 scale (a 7.5'
quad map).

ORDERING:
The coarse DEM/DLG data (250K and 2000K) is a complete data set.  It is
handled by EROS data center.  Price is $40 for 1 file, sliding higher
for 2-4 files; for 5 or more files prices is $90 plus $7/file.  A file
is 1 layer (hydro, trans, boundaries) for 1 section of the country.
There are 21 sections in the 2000K DLG data.

The finer resolution stuff is not a complete data set.  It is handled
by 4 regional ESIC offices; I called EROS Data Center to find out
the name and number of the regional office that handled my particular
area.  The regional office has a listing of what's available.  Prices
seem to be the same as for the coarse data, but of course you'd need
more files for the entire country.

I'm told (by a source at the Texas Water Commission) that if your
particular area of interest has not yet been digitized and is not
on the schedule, you can get it added to the schedule if you're willing
to share the digitizing cost.

A colleague told me that turnaround time for orders ranges from
2 weeks to 3 months.

--
Hal Mueller             hmueller@cssun.tamu.edu          n270ca@tamunix (Bitnet)
Graduate Student, Department of Computer Science
Research Assistant, Department of Wildlife and Fisheries Science
Texas A&M University, College Station, TX 77843