![[View SPOT Regional View]](spot/images/mains.gif)
![3D](https://webarchive.library.unt.edu/eot2008/20081108024258im_/http://terraweb.wr.usgs.gov/icons/3dglassb.gif)
The stereo images shown in previous figures were generated using an existing DEM at 30 meter resolution and artificially introducing horizontal parallax into either the shaded relief of the DEM or Landsat TM images. A more traditional method to get stereo image pairs is to have two images collected of the same area with different viewing angles. The following stereo images were generated using such a procedure. The French
SPOT satellite imaging system has the capability to point either straight down (nadir view) or off to the sides (up to about 27 degrees off nadir view). We had two images collected for the Flagstaff area using the ten meter panchromatic imaging system on
SPOT; the images were collected on November 7,1995 (nadir view) and November 8, 1995 (27 degrees west/off nadir view). These two images were geometrically registered using the
USGSMIPS software and the following stereo images generated. Each of the images shown in the following figures had a contrast stretch applied that optimizes the area's brightness range; the images have a ten, rather than thirty, meter resolution. The 3-D/stereo effect is a very useful way to study and analyze the area's structural features that include surface fractures, faults, and drainages. Figure 13 shows the stereo image made from the two full
SPOT images. Some of the landmarks identified in both the Landsat TM and DEM data can be seen in this figure. Flagstaff is just to the west of center; the San Francisco Peaks are northwest of Flagstaff; Lake Mary and Mormon Lake are in the lower right portion of the image; I-17 and Oak Creek Canyon are in the lower left portion of the image. The red and blue glasses are needed to see the 3-D/stereo effect (red on the left).