Q0007 Downloading and Using Montana DOQQ Image Files in AllTopo V7

Keywords:    Montana, DOQ, DOQQ, Digital Orthophoto Quarter Quadrangle, Arial Photo, UTM Projected Image File,

Q    How do I get Montana DOQ images and use them with AllTopo?

A    Every DOQQ (Digital Orthophoto Quarter Quadrangle) for Montana is available at no charge from the Montana State Library Natural Resource Information System. Here is how to download, convert and use these images in the All Topo viewer:

1. Get the image you need from NRIS. Browse to http://nris.state.mt.us/nsdi/doq.asp; then choose the coverage you need.
2. When you get to the quadrangle you need, download the “UTM Zone 12 Coordinates NAD27 Meters’ image. Don’t download the “Montana State Plane Coordinates” images, they won’t work.
   
   
   

   First download the “World File” by right-clicking over the .’World File SDW’ link and selecting “Save Target As…”. Browse for a folder to put the image in, keep the default name. I use a folder named "C:\DOQQS"
   
      
    

3. Next download the “Image File .SID” to the same folder, by right-clicking on the "Image File" link. Again keep the default image name and put it in the SAME FOLDER!
4. You will need the mrsiddecode.exe tool to convert the .SID compressed image file from .SID format to a GeoTIF image. You can download the conversion too from: http://www.lizardtech.com/download/dl_download.php?detail=geo_mrsiddecode&platform=win
   
   Decompress the .ZIP file to the same folder where you download the .SID image to. You may need to copy the executable file (*.exe) to the DOQQS folder.
5. Convert the .SID file to a GeoTIF. You must run MrSidDecode.exe from the command line. An example command line (for the Billings East Quardrangle) is:
   
         mrsiddecode -i d4510874.sid -o d4510874.tif -of tifg
   
   To run mrsiddecode from the command line, start the command line by clicking on "Start (the green button on the bottom left corner of your screen): All Programs: Accessories: Command Prompt". A black box will come up on your screen. Type "CD \doqqs" (replacing "doqqs" with the full path to the location where you stored all the files you downloaded. If you then type "DIR" and press enter you should see something like this:
   
   
   
   Now you can type the command line "mrsiddecode -i d4510874.sid -o d4510874.tif -of tifg" and you will see something like this:
   
    
6. Once decoded, start the All Topo viewer. Select the main menu option “File: Open BigTopo Map…”. Change the “Files of Type:” selection to ‘UTM Projected Image Files’. Browse for the folder and file that you converted. Press the [Open] button to load the ortho image.
7. AllTopo will ask for the ‘UTM Zone’ and Datum. The Zone should be 12 or 13, the datum NAD27 if you downloaded the image from the NRIS site:
   
                  
   
   Press [OK] when the correct Zone and Datum have been selected.
8. AllTopo will display the map. If your machine struggles loading the map, try toggling the ‘High Quality Display’ OFF until the map is fully loaded, positioned and zoomed. The shortcut key for the ‘High Quality Display’ option is Alt-Q.

02/09/2006 01:30:12 PM -0500