Missoula, Montana
Photo ID: P-46295
May 16, 1996
This is a three-dimensional perspective view of Missoula,
Montana, created by combining two spaceborne radar images using a
technique known as interferometry. Visualizations like this are
useful because they show scientists the shapes of the topographic
features such as mountains and valleys. This technique helps to
clarify the relationships of the different types of materials on
the surface detected by the radar. The view is looking north-
northeast. The blue circular area at the lower left corner is a
bend of the Bitterroot River just before it joins the Clark
Fork, which runs through the city. Crossing the Bitterroot River
is the bridge of U.S. Highway 93. Highest mountains in this image
are at elevations of 2,200 meters (7,200 feet). The city is
about 975 meters (3,200 feet) above sea level. The bright yellow
areas are urban and suburban zones, dark brown and blue-green
areas are grasslands, bright green areas are farms, light brown
and purple areas are scrub and forest, and bright white and blue
areas are steep rocky slopes. The two radar images were taken on
successive days by the Spaceborne Imaging Radar-C/X-band
Synthetic Aperture Radar (SIR-C/X-SAR) on board the space shuttle
Endeavour in October 1994. The digital elevation map was
produced using radar interferometry, a process in which radar
data are acquired on different passes of the space shuttle. The
two data passes are compared to obtain elevation information.
Radar image data are draped over the topography to provide the
color with the following assignments: red is L-band vertically
transmitted, vertically received; green is C-band vertically
transmitted, vertically received; and blue are differences seen
in the L-band data between the two days. This image is centered
near 46.9 degrees north latitude and 114.1 degrees west
longitude. No vertical exaggeration factor has been applied to
the data. SIR-C/X-SAR, a joint mission of the German, Italian and
United States space agencies, is part of NASA's Mission to Planet
Earth program.
![[MISSOULA, MONTANA]](MISSOULA.GIF)