Imaging Radar Home Page
These two images were created using data from the Spaceborne Imaging Radar C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR). The image on the left is a false-color composite of the Mammoth Mountain area in California's Sierra Nevada Mountains centered at 37.6 degrees north, 119.0 degrees west. It was acquired onboard space shuttle Endeavour on its 67th orbit on April 13, 1994. In the image on the left, red is C-band HV-polarization, green is C- band HH-polarization and blue is the ratio of C-band VV- polarization to C-band HV-polarization. On the right is a classification map of the surface features which was developed by SIR-C/X-SAR science team members at the University of California, Santa Barbara. The area is about 23 by 46 kilometers (14 by 29 miles). In the classification image, the colors represent the following surfaces:
snow
frozen lake, covered by snow
bare ground
lake (open water)
short vegetation (mainly brush)
sparse forest
dense forest
Maps like this one are helpful to scientists studying snow wettness and snow water equivelent in the snow pack. Across the globe, over major portions of the middle and high latitudes, and at high elevations in the tropical latitudes, snow and alpine glaciers are the largest contributors to run-off in rivers and to ground-water recharge. Snow hydrologists are using radar in an attempt to estimate both the quantity of water held by seasonal snow packs and the timing of snow melt. Snow and ice also play important roles in regional climates; understanding the processes in seasonal snow cover is also important for studies of the chemical balance of alpine drainage basins. SIR-C/X-SAR is a powerful tool because it is sensitive to most snow pack conditions and is less influenced by weather conditions than other remote sensing instruments, such as the Landsat satellite.
P-43924 April 16, 1994
Imaging Radar Home Page