Mohammad A. Rob (right), Electro-Optics Program--UHCL
Mohammad A. Rob, Ph.D., School of Natural and Applied Sciences, University of Houston Clear Lake
The pulsed TEA CO2 laser purchased through a partial grant from the Institute of Space Systems and Operations (ISSO) will be used in air pollution research at the University of Houston Clear Lake.
The natural and biological processes at the earth's surface and man-made activities, such as burning of fossil fuels (coal, oil, gas) in industry and in automobiles, cause a large number of pollutants to be emitted to the atmosphere. Today, the atmosphere not only contains naturally occurring nitrogen, oxygen, carbon dioxide, and water vapor, but also a large number of pollutant gases such as hydrocarbons (HC), nitric oxides (NO, N2O, NO2), ammonia (NH3), ozone (O3), sulfur dioxide (SO2), carbon oxides (CO2, CO) and some of their reaction products like acids and oxidants. These pollutants are not only of concern to human health but also of long-term environmental concern in global warming, acid rain, etc. Trace gases like CO2, CH4, N2O, O3, and CFC's are effective greenhouse gases that alter the energy balance of planet Earth and, hence, its climate.
The quantification of pollutant molecules in a periodic interval will enable researchers to understand the complex chemical processes that govern the atmosphere. A laser radar (lidar) can be used to detect pollutant molecules while they reside in the atmosphere. Tunable TEA CO2 laser plays an important role in atmospheric pollution monitoring. This effect is attributed to its high output power and overlapping emission spectrum, with the absorption spectra of a large number of molecules of atmospheric concern. ISSO researchers plan to develop a differential absorption lidar (DIAL) using a tunable TEA CO2 laser that can be utilized as a remote sensor for atmospheric pollutants. Specific experiments in progress are devoted to (1) the development of a single-longitudinal mode operation of the laser, (2) measurement of absorption cross sections of various pollutant molecules, and (3) generation of new wavelengths by second harmonic generation of CO2 laser wavelengths.
| Mohammad A. Rob (right), Electro-Optics Program--UHCL |
Takahide Yoshida (left), master's candidate in the electrooptic program at UHCL, works at the continuous-wave CW-CO2 laser, equipment applied to the analysis of air pollution. |
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Colin Atkinson, Ph.D. Department of Computer Science, University of Houston Clear Lake
A proposal for a global disaster warning and migration system (GEOWARN), intended to reduce the impact of natural disasters on mankind, was developed with the help of an ISSO researcher from UHCL. In spite of dramatic improvements in space-based remote sensing, mobile communications, and computer processing technology, the nation's ability to predict disasters and provide adequate relief when they occur is far from satisfactory. The aim of GEOWARN is to use existing technology to provide a global disaster warning and relief support service. The core of the system is a constellation of Low Earth Orbit (LEO) satellites which monitor vulnerable areas of the earth and a global network of computing facilities that analyze the images and provide timely warning of impending disasters. Aircraft carrying Synthetic Aperture Radar will also be used to provide damage assessment and relief support in the event of a disaster. GEOWARN is currently the subject of several NASA and ESA feasibility studies.
An ISSO researcher participated in the project as a part of the 1993 summer session of the International Space University (ISU) at Huntsville, Alabama. ISU is a non-profit organization whose goal is to bring together students, academicians, and experts from all disciplines related to space for an intensive ten-week period of lectures and research. Participants in the ISU summer session attended from all areas of the world.
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W. R. Sheldon, Ph.D., and J. R. Benbrook, Ph.D., Department of Physics
A rocket payload for the in situ measurement of atmospheric ozone has been developed during the past several years by the UH Space and Atmospheric Physics Group. Funds for the development were provided by the Texas Higher Education Coordinating Board. In August 1992, under the support of an ISSO grant, the payload was qualified for flight and test flown at the NASA rocket range at Wallops Island, Virginia. The test flight indicated that the payload components and structure were adequate for the arduous environment of rocket ascent. However, in a region of great interest for this instrument, between 25 and 42 km, the measured ozone profile showed significant deviation from the standard model; the measured decrease in ozone with increasing altitude was much more rapid than indicated by the model.
The failure of the instrument at high altitude was caused by an inadequate gas flow rate. An additional pump has been added to the payload to correct this problem, and the system is currently undergoing a complete recalibration. Researchers plan to fly the payload on an high-altitude balloon from Palestine, Texas, during the September turnaround of the stratospheric winds. We anticipate making the flight without difficulty because of our experience in two previous flights at the site. The combined results of the rocket test last August and the balloon flight test should be adequate to support a proposal to NASA to use UH instrumentation to investigate the characteristics of the Space Shuttle exhaust plume following a launch at the Kennedy Space Center. ISSO has funded this effort these past two years.
Contents
ISSO -- Institute for Space Systems Operations
1992-1993 Annual Report
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