Download or read book Potential Use of a Differential Absorption Lidar Dial Measurement System Relevant to Atmospheric Urban Ozone Processes written by Steven Michael Zubrick and published by . This book was released on 1981 with total page 154 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book An Ozone Differential Absorption Lidar DIAL Receiver System for Use on Unpiloted Atmospheric Vehicles written by Soenke Goldschmidt and published by . This book was released on 1999 with total page 42 pages. Available in PDF, EPUB and Kindle. Book excerpt: Measurements of global atmosphere ozone concentrations call for flexible lidar systems that can be operated from an unpiloted vehicle (UAV) to reduce the cost of measurement missions. A lidar receiver system consisting of a fiber-optic-coupled telescope has been designed and tested for this purpose. The system weight is 13 kg and its volume of 0.06 m[cubed] would fit into the payload compartment of a Perseus B UAV. The optical efficiency of the telescope is 37 percent at 288 nm and 64 percent at 300 nm. Atmospheric measurements with a DIAL laser system have been performed, and the measured ozone density has matched the data from ozonesondes to an altitude of 7 km.
Download or read book Instrument Development for Atmospheric Research and Monitoring written by Jens Bösenberg and published by Springer Science & Business Media. This book was released on 2013-04-17 with total page 420 pages. Available in PDF, EPUB and Kindle. Book excerpt: Jens Bosenberg Max-Planck-Institut fur Meteorologie, Bundesstr. 55, D-20146 Hamburg, Germany TESLAS, which stands for Tropospheric Environmental Studies by Laser Sounding, was formed in November 1987 as a subproject of EUROTRAC to enhance the measurement capabilities for vertical profiling of ozone in the troposphere by means of laser remote sensing. For studies of several atmospheric processes related to the formation and redistribution of photo-oxidants there was a clear need for measuring extended time series with appropriate vertical and temporal resolution. These could not be obtained by conventional in situ techniques, at least not with affordable effort, so remote sensing appeared to be the best way to obtain the required information. At the beginning of the subproject, some Differential Absorption Lidar (DIAL) systems for measuring the vertical distribution of ozone already existed, but their use was restricted to very few laboratories and very few measurement campaigns, since the instruments were highly complex, rather unreliable, and required extensive efforts for maintenance and operation by skilled scientists. In addition, the accuracy of these measurements under a variety of meteorological conditions was not really well established. The main tasks within TESLAS therefore were to develop fully the DIAL-methodology for remote sensing of tropospheric ozone, and to develop instruments which are accurate, reliable, easy to operate, and suitable for field deployment or airborne operation.
Download or read book An Ozone Differential Absorption Lidar Dial Receiver System for Use on Unpiloted Atmospheric Vehicles written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-05-29 with total page 40 pages. Available in PDF, EPUB and Kindle. Book excerpt: Measurements of global atmosphere ozone concentrations call for flexible lidar systems that can be operated from an unpiloted atmospheric vehicle (UAV) to reduce the cost of measurement missions. A lidar receiver system consisting of a fiber-optic-coupled telescope has been designed and tested for this purpose. The system weight is 13 kg and its volume of 0.06 m 3 would fit into the payload compartment of a Perseus B UAV. The optical efficiency of the telescope is 37 percent at 288 nm and 64 percent at 300 nm. Atmospheric measurements with a DIAL laser system have been performed, and the measured ozone density has matched the data from ozonesondes to an altitude of 7 km.DeYoung, Russell J. and Goldschmidt, SoenkeLangley Research CenterOPTICAL RADAR; DIFFERENTIAL ABSORPTION LIDAR; RECEIVERS; TELESCOPES; GAS COMPOSITION; GAS DENSITY; COST REDUCTION
Download or read book Differential Absorption LiDAR for the Total Column Measurement of Atmospheric CO2 from Space written by James Lawrence and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Since the beginning of the industrial revolution (1750 to 1800) the Earth's atmospheric composition has undergone significant change as a result of human activities, in particular the burning of fossil fuels. As a consequence the atmospheric concentrations of a number of gases known to be influential to the Earth's climate have increased far beyond natural levels. Atmospheric gases such as carbon dioxide which naturally exist in the Earth system have increased in correlation with anthropogenic emissions. The effect of this perturbation on the Earth system has been predicted through computer simulations to have undesirable consequences on the Earth's future climate. The present measurement systems for atmospheric carbon dioxide have limited spatial coverage and temporal resolution which restricts their ability to accurately attribute observations of atmospheric composition to particular terrestrial sources and sinks. This inability to accurately locate and quantify the key carbon dioxide sources and sinks in the terrestrial and marine biospheres is hindering the understanding of the processes that are driving the Earth's natural uptake of approximately half of the anthropogenic carbon dioxide emissions. With such uncertainty it is currently unknown precisely how the Earth's climate will respond to global warming in the future. Through computer simulation it has been demonstrated that improving the spatial distribution of global measurements of atmospheric carbon dioxide is likely to advance the present understanding of the Earth's terrestrial sources and sinks. Regions that require particular improvement in measurement coverage are the southern oceans owing to a lack of landmass on which to site instruments, and much of the tropics because of difficulties in locating instruments in some of the worlds more politically unstable regions. Satellite remote sensing instruments which measure atmospheric carbon dioxide from low Earth orbit provide some coverage of these sparsely sampled locations, however cloud cover often prevents measurements being made (particularly in the tropics), and limited latitudinal coverage caused by current instruments using passive remote sensing techniques prevents measurements at very high and low latitudes (including much of the southern ocean during local winter). An alternative remote sensing technique has been proposed in the scientific literature for measuring atmospheric carbon dioxide concentrations using laser emissions from a satellite platform known as total column differential absorption LiDAR (TC-DIAL). The TC-DIAL technique has been identified as having the theoretical potential to meet the coverage and precision requirements to greatly aid in identifying and quantifying terrestrial carbon dioxide sources and sinks. The TC-DIAL technique has the potential to achieve these goals largely owing to its unique capabilities of being able to make measurements during both the day and night and at all latitudes with a footprint which may be small enough to see between patchy cloud cover in the tropics. This thesis builds on previous studies of the TC-DIAL measurement technique from a satellite platform to assess its current and future capabilities to meet the observation requirements defined by the atmospheric carbon and modeling scientific communities. Particular investigations are carried out to assess the optimum system configuration in the context of global carbon modeling using up-to-date spectroscopy and instrument parameters for the latest technology. Optimum systems for both direct and heterodyne detection TC-DIAL instruments are defined, and it is found that direct detection provides the lowest retrieval errors under clear sky conditions. For a system based on current technology TC-DIAL retrievals are expected to have errors of approximately 0.68 ppm for direct detection and 1.01 ppm for heterodyne detection over a 50 km surface track. Using global cloud statistics two suitable pulse repetition frequencies (PRF) for a heterodyne detection system have been identified as 5 and 15 kHz. These PRF's provide the minimum probability of an effect known as cross signal contamination occurring when measurements are made in the presence of cloud. In this thesis it is shown that the retrieval error incurred by cross signal contamination is> 16 ppm for a heterodyne detection TC-DIAL system measuring through cloud with optical depth> 2. The most important retrieval error component in TC-DIAL retrievals has been found to be the uncertainties introduced by the use of numerical weather prediction data for the ancillary atmospheric profiles. The limited spatial resolution of current NWP models (> 20 km) implies the uncertainties associated with the ancillary data are required to be treated as systematic, and as a consequence their errors dominate over other TC-DIAL retrieval errors following multiple pulse integration.
Download or read book Design of Advanced Atmospheric Water Vapor Differential Absorption Lidar Dial Detection System written by National Aeronautics and Space Adm Nasa and published by Independently Published. This book was released on 2018-09-19 with total page 44 pages. Available in PDF, EPUB and Kindle. Book excerpt: The measurement of atmospheric water vapor is very important for understanding the Earth's climate and water cycle. The lidar atmospheric sensing experiment (LASE) is an instrument designed and operated by the Langley Research Center for high precision water vapor measurements. The design details of a new water vapor lidar detection system that improves the measurement sensitivity of the LASE instrument by a factor of 10 are discussed. The new system consists of an advanced, very low noise, avalanche photodiode (APD) and a state-of-the-art signal processing circuit. The new low-power system is also compact and lightweight so that it would be suitable for space flight and unpiloted atmospheric vehicles (UAV) applications. The whole system is contained on one small printed circuit board (9 x 15 sq cm). The detection system is mounted at the focal plane of a lidar receiver telescope, and the digital output is read by a personal computer with a digital data acquisition card.Refaat, Tamer F. and Luck, William S., Jr. and DeYoung, Russell J.Langley Research CenterATMOSPHERIC MOISTURE; WATER VAPOR; DESIGN ANALYSIS; DIFFERENTIAL ABSORPTION LIDAR; DETECTION; AVALANCHES; SENSITIVITY; LOW NOISE; PHOTODIODES; SIGNAL PROCESSING; PRINTED CIRCUITS; LOW WEIGHT; SIGNAL TO NOISE RATIOS; ATMOSPHERIC SOUNDING
Download or read book Differential Absorption Lidars for Remote Sensing of Atmospheric Pressure and Temperature Profiles written by and published by . This book was released on 1995 with total page 262 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Air Pollution Processes in Regional Scale written by Dimitrios Melas and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 399 pages. Available in PDF, EPUB and Kindle. Book excerpt: An understanding of long-range transport of air pollutants in the atmosphere requires a knowledge of the relevant atmospheric dynamic and chemical processes active at the regional scale as well as the temporal and spatial distribution of emissions. Numerical modeling is the most efficient way to determine the atmospheric transport, photochemistry and deposition pathways. The book therefore discusses the physical and chemical processes that determine regional air pollution and presents the relevant modeling techniques to describe the different atmospheric processes that are active at that scale.
Download or read book Comparison of Differential Absorption Lidar with in Situ Aircraft Measurements of Ozone Concentrations written by Honey Lynne Walters and published by . This book was released on 2003 with total page 154 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Atmospheric Effects on CO2 Differential Absorption Lidar Sensitivity written by and published by . This book was released on 1996 with total page 16 pages. Available in PDF, EPUB and Kindle. Book excerpt: The ambient atmosphere between the laser transmitter and the target can affect CO2 differential absorption lidar (DIAL) measurement sensitivity through a number of different processes. In this work, we will address two of the sources of atmospheric interference with CO2 DIAL measurements: effects due to beam propagation through atmospheric turbulence and extinction due to absorption by atmospheric gases. Measurements of atmospheric extinction under different atmospheric conditions are presented and compared to a standard atmospheric transmission model (FASCODE). We have also investigated the effects of atmospheric turbulence on system performance. Measurements of the effective beam size after propagation are compared to model predictions using simultaneous measurements of atmospheric turbulence as input to the model. These results are also discussed in the context of the overall effect of beam propagation through atmospheric turbulence on the sensitivity of DIAL measurements.
Download or read book Pressure Measurements Using an Airborne Differential Absorption Lidar Part 1 Analysis of the Systematic Error Sources written by National Aeronautics and Space Adm Nasa and published by Independently Published. This book was released on 2018-09-20 with total page 52 pages. Available in PDF, EPUB and Kindle. Book excerpt: Remote airborne measurements of the vertical and horizontal structure of the atmospheric pressure field in the lower troposphere are made with an oxygen differential absorption lidar (DIAL). A detailed analysis of this measurement technique is provided which includes corrections for imprecise knowledge of the detector background level, the oxygen absorption fine parameters, and variations in the laser output energy. In addition, we analyze other possible sources of systematic errors including spectral effects related to aerosol and molecular scattering interference by rotational Raman scattering and interference by isotopic oxygen fines.Flamant, Cyrille N. and Schwemmer, Geary K. and Korb, C. Laurence and Evans, Keith D. and Palm, Stephen P.Goddard Space Flight CenterREMOTE SENSING; ATMOSPHERIC PRESSURE; PRESSURE MEASUREMENT; VERTICAL DISTRIBUTION; DIFFERENTIAL ABSORPTION LIDAR; RAMAN SPECTRA; AEROSOLS; TROPOSPHERE; SYSTEMATIC ERRORS; OPTICAL RADAR
Download or read book Energy Research Abstracts written by and published by . This book was released on 1994-11 with total page 486 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Design of Advanced Atmospheric Water Vapor Differential Absorption Lidar DIAL Detection System written by Tamer F. Refaat and published by . This book was released on 1999 with total page 46 pages. Available in PDF, EPUB and Kindle. Book excerpt: The measurement of atmospheric water vapor is very important for understanding the Earth's climate and water cycle. The lidar atmospheric sensing equipment (LASE) is an instrument designed and operated by Langley Research Center for high precision water vapor measurements. The design details of a new water vapor lidar detection system that improves the measurement sensitivity of the LASE instrument by a factor of 10 are discussed. The new system consists of an advanced, very low noise, avalanche photodiode (APD) and a state-of-the-art signal processing unit. The new low-power system is also compact and lightweight so that it would be suitable for space flight and unpiloted atmospheric vehicles (UAV) applications. The whole system is contained on one small printed circuit board (9 by 15 cm[squared]). The detection system is mounted at the focal plane of a lidar receiver telescope, and the digital output is read by a personal computer with a digital data acquisition card.
Download or read book Advances in Atmospheric Remote Sensing with Lidar written by Albert Ansmann and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 603 pages. Available in PDF, EPUB and Kindle. Book excerpt: Lidar or laser radar, the depth-resolved remote measurement of atmospheric parameters with optical means, has become an important tool in the field of atmospheric and environmental remote sensing. In this volume the latest progress in the development of Lidar methods, experiments, and applications is described. The content is based on selected and thoroughly refereed papers presented at the 18th International Laser Radar Conference, Berlin, 22 - 26 July 1996. The book is divided into six parts which cover the topics of tropospheric aerosols and clouds, Lidar in space, wind, water vapor, troposheric trace gases and plumes, and stratospheric and mesospheric profiling. As a supplement to fundamental LIDAR textbooks this volume may serve as a guide through the blossoming field of modern Lidar techniques.
Download or read book Acid Precipitation written by and published by . This book was released on 1990 with total page 812 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Ultra Narrowband Optical Filters for Water Vapor Differential Absorption Lidar Dial Atmospheric Measurements written by National Aeronautics and Space Adm Nasa and published by Independently Published. This book was released on 2018-09-17 with total page 36 pages. Available in PDF, EPUB and Kindle. Book excerpt: Differential absorption lidar (DIAL) systems are being deployed to make vertical profile measurements of atmospheric water vapor from ground and airborne platforms. One goal of this work is to improve the technology of such DIAL systems that they could be deployed on space-based platforms. Since background radiation reduces system performance, it is important to reduce it. One way to reduce it is to narrow the bandwidth of the optical receiver system. However, since the DIAL technique uses two or more wavelengths, in this case separated by 0.1 nm, a fixed-wavelength narrowband filter that would encompass both wavelengths would be broader than required for each line, approximately 0.02 nm. The approach employed in this project is to use a pair of tunable narrowband reflective fiber Bragg gratings. The Bragg gratings are germanium-doped silica core fiber that is exposed to ultraviolet radiation to produce index-of-refraction changes along the length of the fiber. The gratings can be tuned by stretching. The backscattered laser radiation is transmitted through an optical circulator to the gratings, reflected back to the optical circulator by one of the gratings, and then sent to a photodiode. The filter reflectivities were >90 percent, and the overall system efficiency was 30 percent.Stenholm, Ingrid and DeYoung, Russell J.Langley Research CenterBRAGG GRATINGS; DIFFERENTIAL ABSORPTION LIDAR; NARROWBAND; OPTICAL FILTERS; REFLECTANCE; ATMOSPHERIC MOISTURE; BACKSCATTERING; DOPED CRYSTALS
Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1995 with total page 400 pages. Available in PDF, EPUB and Kindle. Book excerpt:
