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NASA finds new techniques for mapping earth's gases
coastal desert regions of Peru. Because of the similarity between the Egyptian sites and the Peruvian fields, this may represent previously unrecognized pastoral or agricultural sites in southern Egypt. Previous to these discoveries the potential for subsurface radar imaging had been discussed but very little work has actually been undertaken. Radar penetration is theoretically possible under a very limited range of conditions which are a function of the characteristics of the radar system and the local ground surface. The surface of the ground should be extremely smooth, thus allowing the radar signal to enter the ground rather than to break up and backscatter away from the radar’s antenna. The ground electrical characteristics should also be virtually transparent to the radar signal, desiccated sand being a very good example, wet clay soil being a bad example. The angle the radar signal strikes the ground is also important as is the wavelength and the power. The radar signal is attenuated as it passes through the sand, both on the downward journey and the return upward journey. The type of underlying material, the degree of backscatter, the reflection angle and polarization are all important characteristics associated with this subsurface radar imaging. The physics involved is not yet thoroughly defined. Based on the Shuttle radar results, laboratory studies the better to define the theory and practical applications of this are underway. The Principal Investigator for the Shuttle Imaging experiment is Dr. Charles Elachi, NASA Jet Propulsion Laboratory. Principal work for the remote sensing geoarchaeology was done by Jack McCauley, Gerald Shaber, Carol Breed, Maurice Golier, all with the US Geological Survey, Flagstaff, Ariz., C. Vance Haynes, University of Arizona, Tucson, Bahay Issawi, Egyptian Geological Survey and Mining Authority, Cairo, and Charles Elachi and Ronald Blom, NASA JPL.
3.11. NASA FINDS NEW TECHNIQUES FOR MAPPING EARTH’S GASES@’
A new technique for mapping gases in the earth’s atmosphere proved accurate when compared with ground-initiated studies. The Measurement of Pollution from Satellites (MAPS) experiment flown aboard the second Shuttle flight November 1981, charted concentrations of gases around the world over a range of latitudes from 38”s to 38”N. The experiment was flown as part of the first scientific payload on the Shuttle and used a gas filter radiometer to produce measurements of the carbon monoxide mixing ratio in the middle troposphere, upper troposphere and lower troposphere. The radiometer method is simpler and much less expensive than previous gas chromatograph devices. Although the experiment produced concentration maps of carbon monoxide, the primary objective was to verify the use of this cheaper “‘NASA News Release No. 82-176 of 23 November 1982.
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technique as an orbital pollution monitor. The results confirm the usefulness of radiometers to perform the job. Data were collected during an orbital pass of the Shuttle that began over central America, continued east over the Mediterranean Sea, turned south-east over the Persian Gulf, the Arabian Sea and extended to the southern tip of India. The concentration of carbon monoxide within this extended area ranges from 70 parts per billion over the Americas to a high of 115 parts per billion over the eastern Atlantic Ocean and 140 parts per billion in the Mediterranean area. The analysis of experiment data so far indicate significant concentrations of middle troposphere carbon monoxide mixing with both north/south and east/west variation over the north Atlantic and the M~ite~~~n Sea and the Middle East. Accuracy of the measurements has been determined to be within 15% with a repeatability to about 5% from orbit to orbit. NASA plans to refly this experiment on the 17th Shuttle, scheduled for the summer of 1984, to study seasonal variations in the total abund~ce and regional distribution of carbon monoxide within the earth’s atmosphere. Although the SIX-2 flight was abbreviated, the experiment lasted for about 42 hours, and the investigators were able to corroborate the sampled areas with the instrument readings taken with under-flying aircraft and with other surface truth info~ation. The instrument was constructed at NASA’s Langley Research Center, Hampton, Va. Dr. Henry G. Reiche Jr. is the principal investigator, with assistance from Langley personnel, in addition to the Old Dominion University, Norfolk, and Systems and Applied Sciences Corp., Hampton,
3.12. SHUlTLE EXPERIMENT LOCATES ORE DEPOSITS”’ A previously unprospected area, potentially rich in ore deposits, has been located in a remote Mexican desert by an infrared instrument carried on NASA’s Space Shuttle. The finding marks the first time that a group of minerals typical of metal-rich areas has been pinpointed from space. Mineral identifications made by the Shuttle-borne instrument were verified at the site in co-operative research last October by American and Mexican scientists. This project was sponsored on the Mexican side by the Secretario de Pat~mo~o y Ferment0 Indust~al. The new results from the Shuttle Multispectral Infrared Radiometer (SMIRR) experiment, flown on the Columbia in November 1981, were reported at the International Symposium on Remote Sensing for Exploration Geology in Ft. Worth, Texas, by co-investigators Dr. Alexander F. H. Goetz of NASA’s Jet Propulsion Laboratory, Pasadena, Calif., and Dr. Lawrence C. Rowan of the US Geological Survey, Reston, Va. Radiometer measurements of the Baja California site were found to have identified iron oxide minerals as well as kaolinite (a clay), and possibly alunite (a “‘NASA News Release No. 82-182 of 6 December 1982.
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3.11. NASA FINDS NEW TECHNIQUES FOR MAPPING EARTH’S GASES@’
A new technique for mapping gases in the earth’s atmosphere proved accurate when compared with ground-initiated studies. The Measurement of Pollution from Satellites (MAPS) experiment flown aboard the second Shuttle flight November 1981, charted concentrations of gases around the world over a range of latitudes from 38”s to 38”N. The experiment was flown as part of the first scientific payload on the Shuttle and used a gas filter radiometer to produce measurements of the carbon monoxide mixing ratio in the middle troposphere, upper troposphere and lower troposphere. The radiometer method is simpler and much less expensive than previous gas chromatograph devices. Although the experiment produced concentration maps of carbon monoxide, the primary objective was to verify the use of this cheaper “‘NASA News Release No. 82-176 of 23 November 1982.
68
technique as an orbital pollution monitor. The results confirm the usefulness of radiometers to perform the job. Data were collected during an orbital pass of the Shuttle that began over central America, continued east over the Mediterranean Sea, turned south-east over the Persian Gulf, the Arabian Sea and extended to the southern tip of India. The concentration of carbon monoxide within this extended area ranges from 70 parts per billion over the Americas to a high of 115 parts per billion over the eastern Atlantic Ocean and 140 parts per billion in the Mediterranean area. The analysis of experiment data so far indicate significant concentrations of middle troposphere carbon monoxide mixing with both north/south and east/west variation over the north Atlantic and the M~ite~~~n Sea and the Middle East. Accuracy of the measurements has been determined to be within 15% with a repeatability to about 5% from orbit to orbit. NASA plans to refly this experiment on the 17th Shuttle, scheduled for the summer of 1984, to study seasonal variations in the total abund~ce and regional distribution of carbon monoxide within the earth’s atmosphere. Although the SIX-2 flight was abbreviated, the experiment lasted for about 42 hours, and the investigators were able to corroborate the sampled areas with the instrument readings taken with under-flying aircraft and with other surface truth info~ation. The instrument was constructed at NASA’s Langley Research Center, Hampton, Va. Dr. Henry G. Reiche Jr. is the principal investigator, with assistance from Langley personnel, in addition to the Old Dominion University, Norfolk, and Systems and Applied Sciences Corp., Hampton,
3.12. SHUlTLE EXPERIMENT LOCATES ORE DEPOSITS”’ A previously unprospected area, potentially rich in ore deposits, has been located in a remote Mexican desert by an infrared instrument carried on NASA’s Space Shuttle. The finding marks the first time that a group of minerals typical of metal-rich areas has been pinpointed from space. Mineral identifications made by the Shuttle-borne instrument were verified at the site in co-operative research last October by American and Mexican scientists. This project was sponsored on the Mexican side by the Secretario de Pat~mo~o y Ferment0 Indust~al. The new results from the Shuttle Multispectral Infrared Radiometer (SMIRR) experiment, flown on the Columbia in November 1981, were reported at the International Symposium on Remote Sensing for Exploration Geology in Ft. Worth, Texas, by co-investigators Dr. Alexander F. H. Goetz of NASA’s Jet Propulsion Laboratory, Pasadena, Calif., and Dr. Lawrence C. Rowan of the US Geological Survey, Reston, Va. Radiometer measurements of the Baja California site were found to have identified iron oxide minerals as well as kaolinite (a clay), and possibly alunite (a “‘NASA News Release No. 82-182 of 6 December 1982.
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