Digital Elevation Model (DEM) Terrain Displacement

• Click the GIS Data tab across the top of the page.
• Click the Download GIS Data button.
• Click the Washington State image on the U.S. map.
• Click the Pierce County link.
• Click the 24K DEM link.

This next page is where you will find the quad names to download. Search the list and you will come to our first quad, Golden Lakes. On the right side you will see two download links. A green one and a tan one. The green one is the free download, and the tan one is for the premium download accounts. The only difference is download speed. You also have the option to add them to the cart and purchase them on CD via the mail. However you get the files is completely up to you. I will be using the free method for this tutorial. Once you get to the download page you may have two options. The 10 meter and 30 meter image. This has to do with resolution of the image. The lower the number the finer the detail and better overall quality. For this tutorial we will be using 10 meter DEM data for all quads. Sometimes you will only have the 30 meter option. Always opt for the best quality possible, for obvious reason. There may also be cases where you have all 10 meter DEMs for most of your location but one quad will only have 30 meter available. That's a judgment call on your part. I've mixed and matched resolutions before and just made sure to keep that area out of the focal point of the rendered frame. It looked fine for the shot I was doing...again, your call.

For clarification issues I tend to rename the files being downloaded. As you can see in this case the default name does not represent something logical that we can distinguish quickly. I would append the file name to be something like:

• "GoldenLakes - 1675707.DEM.SDTS.TAR.GZ"

Again, this is just me but I find with all the organization that will be needed in later steps it helps to keep quad names straight. Go ahead and repeat this process for downloading all 15 quads shown in this image.