ArcINFO - Viewing USGS DOQ/DOQQs

 

Viewing the USGS DOQQs in ArcINFO requires the use of the "Create HDR file from Uncompressed DOQ" script.

Scripts and instructions for using them are provided here.

 





1. What is a DOQ and a DOQQ?

 

A DOQ is a digital image of the earth’s surface that has been digitally scanned and processed to remove the distortion inherent in aerial photography. Using a digital elevation model and advanced image processing techniques, radial and topographic distortion is removed from the image providing a true planimetric product. A DOQ image typically covers one-quarter of a 1:24,000 scale USGS topographic map plus a little overlap. The resolution of the image is quite high at one square meter per pixel. As a result of this fine cell size, these images consume large quantities of disk space. A DOQQ is a subset of a DOQ, in that it refers to a Digital Orthophoto Quarter Quad. There are four DOQQ's in a DOQ.

 

For a further description of DOQ's go to the source of our data:http://www-wmc.wr.usgs.gov/orthophoto_basic.html

 

The UW Map Collection has almost 1800 USGS DOQQs for the State of Washington. These quads are available in compressed format, along with file-specific metadata through the website http://duff.ess.washington.edu/data/raster/doqs/. Uncompressed DOQ/DOQQ files are on CD-ROMs stored in the Map Collection.These CDs do not circulate. Patrons can come in, find the CD they need, do some initial reformatting if necessary, and use either FTP or a CD, DVD, or thumb drive to transport the files. Please bring your own media for transporting files. If you have any questions, please contact gis@lib.washington.edu.

Viewing the USGS DOQQs in ArcView requires the use of the "Create HDR file from Uncompressed DOQ" script which we have placed here http://wagda.lib.washington.edu/gishelp/ext/AI/doq_newhdr.aml



2. Finding your DOQQs

  1. First of all, find out if the Map Library has a DOQQ for your area. Look at http://duff.ess.washington.edu/data/raster/doqs/ for a coverage index. The DOQQs are listed both by Washington State Department of Natural Resources Numbering Scheme, and by USGS Quad Name. Look at a UGSG topographic index map for the State of Washington to find out your quad names (this index is available in the Map Collection).
  2. Click on the area of the map for the quads you need. This will take you to a chart which looks like this:

    quadrant/quad      DNR# image date lower left CDROM CDROM file download file Mbytes zipfile meta
    NE Seattle North 1122 1990-7-10 47°41'15" -122°18'45" 231031_4 o4712222_nes 47122f3_ne_1990.tif 42M 36M text

  3. To view metadata for your selected DOQQs, click on the "text" link in the right-hand column.
  4. Compressed DOQ files are linked to the chart column "zipfile" just to the left of the metadata link. In this example it reads 36M (meaning the compressed filesize is 36 MB). The downloaded filename is provided in the column 3rd from the right (47122f3_ne_1990.tif).
  5. Unzip the compressed file using WinZip or other software.
  6. Find the uncompressed file named 47122f3_ne_1990.tif. Rename this file to 47122f3ne1990.doq.
  7. Start your web browser (Internet Explorer or Netscape).





3. Download doq_newhdr.aml

  1. Point your browser to http://wagda.lib.washington.edu/gishelp/ext/AI/doq_newhdr.aml (right click over link and choose "Save target as ...")
  2. Download doq_newhdr.aml to the d:\temp drive.
  3. Close your browser. Start Arc/Info.




4. In ArcINFO:

  1. Go to Arc/Info. Change working directory to d:\temp. ("w d:\temp")
  2. Type "&run doq_newhdr" to see the command's syntax. Type "&run doq_newhdr doqname> <NAD27 | NAD83> <xshift> <yshift>" to convert your doq. For example, "&run doq_newhdr 47122f3ne1990.doq nad83 0 0."
  3. A *.hdr file will be created.

Viewing your DOQQ in Arc/Info

  1. Type the following sequence:
    • arc: display 9999 4
      arc: arcplot
      arcplot: mape image 47122f3ne1990.bil
      arcplot: image 47122f3ne1990.bil