----------------------------Original message----------------------------
About a month ago, I asked whether anyone could tell us how
to bring the data on the U.S. conterminous land cover
characteristics disk(s) into ArcView. No one answered! Since
then, University of Chicago Map Assistant Bob Knippen
figured it out, and, while I'm sure this will be old hat to
some of you, it was all new to us, and I thought some of you
too might be interested in the, well, recipe.
 
What you have to do (in short) is turn the .img files on the
disk(s) into .bmp files. We did this with a program called the
Image Machine, which is available at the ftp site at
starhawk.jpl.nasa.gov in pub/display; the file name of the
zipped file is imach1.zip. ArcView will display this .bmp
image, but, to overlay GIS vector data, you have to add a
World file, indicating the coordinates of the upper left
pixel (if you want the entire U.S the x coordinate is -2050
and the y coordinate is 752) as well as the pixel size (1).
You also have to set the projection correctly (Lambert equal
area azimuthal, with a central meridian of -100 and a
reference latitude of 45) and indicate the map unit
(kilometers). Once this is done, you can add roads, county
boundaries, or whatever to the basic data.
 
The most time-consuming job is creating a legend. Bob
couldn't figure out any way to do this "automatically" (can
anyone help?) and ended up using PaintShopPro. You wouldn't
want to have to do this for a map with dozens of colors.
 
Working all this out was an excellent way to get to know
how ArcView 3.0 deals with "foreign" raster data. And the
happy result was making a previously unused government data
set into something of real utility.
 
If anyone has any questions, the best person to send them to
is Bob Knippen whose e-mail address is [log in to unmask]
 
Chris Winters
University of Chicago Library
 
 
Internet:        [log in to unmask]