GIS Topo Map Instructions
Revised: December 13, 2004
1:24000 Scale Map Images
1:24000 scale Quad images are located in the QUADS directory. There
are three sets of subdirectories Q#,Q#C, and Q#P inside the the directory. They
contain black and white, color, and photo quads respectively. The # sign stands
for a number between 0 and 4. The images are stored in their respective number
subdirectory based upon the first digit in the quad number. For an explanation
of the quad numbering system see this graphic.
"Collarless" maps (maps which have had their border information removed so
they can be seamlessly joined together) use the character p before the
quad number in the image naming scheme (q####.tif for collared version and
pq####.tif for the collarless version).
1:100000 and 1:250000 Scale Map Images
1:100000 and 1:250000 images are stored in two sets of directories named
QUAD### and QUAD###C for black and white and color quad maps
respectively where ### stands for the scale which is either 100 or 250.
Batch Downloads
Copying all the DRG's can be very tedious. If you want to do that regularly you may want to consider using
the following procedure:
- Create a temporary folder in which to download the images. Keep the path
simple since you will need to navigate to this location later with DOS
commands. I suggest "c:\tempdrg".
- Download a program called WGET
This program is a command line utility which will download data from a
website into files on your machine. Install WGET in the temporary directory created above.
- Download into the tempdrg directory nocollar.txt for the collarless DRG's
or collar.txt for the DRG's with the collar.
- Open a command prompt (in XP the command prompt window is hidden in
accessories). Navigate to the temporary folder you created in the steps
above. The DOS command to accomplish
this is CD \tempdrg followed by the enter key.
- Download the documents in the file you have prepared using the following
command (assuming you have used the name nocollar.txt for your
download list file as suggested above):
WGET -i nocollar.txt
followed by the enter key. The WGET program may take several minutes to
download the files depending on the speed of your internet connection
and the number of files being downloaded. Status of the process is
displayed in the command prompt window as the download occurs.
