Nov 23 1982
From The Space Library
The Shuttle imaging radar (SIR) flown on STS-2 in November 1981 had revealed previously unknown river channels, geologic structures, and possible Stone Age occupation sites in the eastern Sahara desert.
JPL's Dr. Charles Elachi, principal investigator for SIR, reported that the radar signal could penetrate the virtually featureless desert surface to show subsurface features nearly as broad as the Nile Valley and up to 50-million years old. Drainage networks detected by radar and confirmed by ground studies would explain the location of present oases in the desert. This new tool could serve in the search for ground water in such arid regions.
Dr. Alexander "Goetz" of JPL said that the multispectral infrared radiometer flown on the same Shuttle mission had made the first detection from orbit of clay and carbonite-bearing minerals, an important step in the use of remote sensing for geological mapping. The device used an area in Egypt of known mineral content as a baseline for analysis; its narrow spectral resolution made it able to map mineral content in the area, using specific substances as a guide for exploration and development, previously possible only through laboratory sampling techniques.
Dr. Henry C. Reiche, Jr., of LaRC was the principal investigator for the MAPS (measurement of atmospheric pollution from satellites) experiment flown on STS-2, which proved accurate when compared to ground studies. A gas-filter radiometer, part of the first scientific Shuttle payload, measured car-bon monoxide ratios in the lower, upper, and middle troposphere, data to be used in 1984 for seasonal variation studies.
Besides the desert features revealed by the Shuttle radar, Elachi reported readings over densely forested areas such as the U.S. Appalachians, the mountains covered by rain forests in western Guyana and Venezuela, and other remote locations not covered by ground survey. Geologic features shown in the radar images would help identify causes of change: erosion, fault lines, or previously unknown fractures of the Earth's crust. The devices recorded their findings because the Shuttle lacked communications capacity. (NASA Releases 82-174, 82-175, 82-176, 82-177; W Post, Nov 26/82, A-l)
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