Download or read book Advanced atmospheric water vapor DIAL detection system written by and published by DIANE Publishing. This book was released on with total page 155 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Advanced Atmospheric Water Vapor DIAL Detection System written by Tamer F. Refaat and published by . This book was released on 2000 with total page 158 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis describes the design and validation of this new water vapor DIAL detection system which was integrated onto a small Printed Circuit Board (PCB) with minimal weight and power consumption. Comparing its measurements to an existing DIAL system for aerosol and water vapor profiling validated the detection system.
Download or read book Advanced Atmospheric Water Vapor Dial Detection System Nasa written by United States. National Aeronautics and Space Administration and published by . This book was released on 2002* with total page 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 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 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 Design Of Advanced Atmosphere Water Vapor Differential Absorption Lidar Dial Detection System NASA TP 1999 209348 August 6 1999 written by and published by . This book was released on 1999* with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Characterization of advanced avalanche photodiodes for water vapor lidar receivers written by and published by DIANE Publishing. This book was released on with total page 62 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Advanced Water Vapor Lidar Detection System written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-08-10 with total page 26 pages. Available in PDF, EPUB and Kindle. Book excerpt: In the present water vapor lidar system, the detected signal is sent over long cables to a waveform digitizer in a CAMAC crate. This has the disadvantage of transmitting analog signals for a relatively long distance, which is subjected to pickup noise, leading to a decrease in the signal to noise ratio. Generally, errors in the measurement of water vapor with the DIAL method arise from both random and systematic sources. Systematic errors in DIAL measurements are caused by both atmospheric and instrumentation effects. The selection of the on-line alexandrite laser with a narrow linewidth, suitable intensity and high spectral purity, and its operation at the center of the water vapor lines, ensures minimum influence in the DIAL measurement that are caused by the laser spectral distribution and avoid system overloads. Random errors are caused by noise in the detected signal. Variability of the photon statistics in the lidar return signal, noise resulting from detector dark current, and noise in the background signal are the main sources of random error. This type of error can be minimized by maximizing the signal to noise ratio. The increase in the signal to noise ratio can be achieved by several ways. One way is to increase the laser pulse energy, by increasing its amplitude or the pulse repetition rate. Another way, is to use a detector system with higher quantum efficiency and lower noise, on the other hand, the selection of a narrow band optical filter that rejects most of the day background light and retains high optical efficiency is an important issue. Following acquisition of the lidar data, we minimize random errors in the DIAL measurement by averaging the data, but this will result in the reduction of the vertical and horizontal resolutions. Thus, a trade off is necessary to achieve a balance between the spatial resolution and the measurement precision. Therefore, the main goal of this research effort is to increase the signal to noise ratio by a factor of 1...
Download or read book Atmospheric Water Vapor written by Adarsh Deepak and published by Elsevier. This book was released on 2013-09-25 with total page 712 pages. Available in PDF, EPUB and Kindle. Book excerpt: Atmospheric Water Vapor contains the technical proceedings of the International Workshop on Atmospheric Water Vapor held in Vail, Colorado, on September 11-13, 1979. The papers assess the state-of-the-art in measurement, modeling, and application of atmospheric water vapor properties and highlight important problems that require further effort in order to better understand the atmosphere itself as well as the electromagnetic propagation through the atmosphere. Comprised of 39 chapters, this book begins with a discussion on the optics and spectroscopy of water vapor. Some actual spectra showing the problems specific to the water molecule are described, along with the method used to calculate precise vibration-rotation energy levels and wave functions. Atmospheric infrared transmission measurements in maritime locations are also presented. Subsequent sections explore microwave and millimeter wave phenomena; geoastrophysical applications; and in situ measurements, remote sensing, and meteorology of water vapor. The final chapters deal with the microphysics and atmospheric chemistry of water vapor. This monograph will be of interest to scientists from universities, government agencies, research laboratories, and industry.
Download or read book Characterization of Advanced Avalanche Photodiodes for Water Vapor Lidar Receivers 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 62 pages. Available in PDF, EPUB and Kindle. Book excerpt: Development of advanced differential absorption lidar (DIAL) receivers is very important to increase the accuracy of atmospheric water vapor measurements. A major component of such receivers is the optical detector. In the near-infrared wavelength range avalanche photodiodes (APD's) are the best choice for higher signal-to-noise ratio, where there are many water vapor absorption lines. In this study, characterization experiments were performed to evaluate a group of silicon-based APD's. The APD's have different structures representative of different manufacturers. The experiments include setups to calibrate these devices, as well as characterization of the effects of voltage bias and temperature on the responsivity, surface scans, noise measurements, and frequency response measurements. For each experiment, the setup, procedure, data analysis, and results are given and discussed. This research was done to choose a suitable APD detector for the development of an advanced atmospheric water vapor differential absorption lidar detection system operating either at 720, 820, or 940 nm. The results point out the benefits of using the super low ionization ratio (SLIK) structure APD for its lower noise-equivalent power, which was found to be on the order of 2 to 4 fW/Hz(sup (1/2)), with an appropriate optical system and electronics. The water vapor detection systems signal-to-noise ratio will increase by a factor of 10.Refaat, Tamer F. and Halama, Gary E. and DeYoung, Russell J.Langley Research CenterDIFFERENTIAL ABSORPTION LIDAR; ATMOSPHERIC MOISTURE; AVALANCHE DIODES; MOISTURE METERS; PHOTODIODES; RADAR RECEIVERS; WATER VAPOR; CHARACTERIZATION; RADAR MEASUREMENT; FREQUENCY RESPONSE; IONIZATION; NOISE REDUCTION; SIGNAL TO NOISE RATIOS; ELECTRIC POTENTIAL; NOISE MEASUREMENT
Download or read book Characterization of Advanced Avalanche Photodiodes for Water Vapor Lidar Receivers written by Tamer F. Refaat and published by DIANE Publishing. This book was released on 2000 with total page 66 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Springer Handbook of Atmospheric Measurements written by Thomas Foken and published by Springer Nature. This book was released on 2021-11-09 with total page 1761 pages. Available in PDF, EPUB and Kindle. Book excerpt: This practical handbook provides a clearly structured, concise and comprehensive account of the huge variety of atmospheric and related measurements relevant to meteorologists and for the purpose of weather forecasting and climate research, but also to the practitioner in the wider field of environmental physics and ecology. The Springer Handbook of Atmospheric Measurements is divided into six parts: The first part offers instructive descriptions of the basics of atmospheric measurements and the multitude of their influencing factors, fundamentals of quality control and standardization, as well as equations and tables of atmospheric, water, and soil quantities. The subsequent parts present classical in-situ measurements as well as remote sensing techniques from both ground-based as well as airborn or satellite-based methods. The next part focusses on complex measurements and methods that integrate different techniques to establish more holistic data. Brief discussions of measurements in soils and water, at plants, in urban and rural environments and for renewable energies demonstrate the potential of such applications. The final part provides an overview of atmospheric and ecological networks. Written by distinguished experts from academia and industry, each of the 64 chapters provides in-depth discussions of the available devices with their specifications, aspects of quality control, maintenance as well as their potential for the future. A large number of thoroughly compiled tables of physical quantities, sensors and system characteristics make this handbook a unique, universal and useful reference for the practitioner and absolutely essential for researchers, students, and technicians.
Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1995 with total page 702 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Monthly Catalog of United States Government Publications written by and published by . This book was released on 2000-02 with total page 148 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Monitoring Atmospheric Water Vapour written by Niklaus Kämpfer and published by Springer Science & Business Media. This book was released on 2012-09-11 with total page 325 pages. Available in PDF, EPUB and Kindle. Book excerpt: Atmospheric water plays a key role in climate. Water vapour is the most important greenhouse gas and its condensed forms exert a profound influence on both incoming solar and outgoing infrared radiation. Unfortunately, accurate, height-resolved global-scale measurements of atmospheric humidity are difficult to obtain. The change in concentration of five orders of magnitude form the ground to the stratosphere means there is no standard instrument that will measure everywhere. This has led to different measuring techniques, all with strengths and weaknesses. This book assesses all presently available techniques that are used in monitoring networks. Special weight is given to presenting the different technical concepts, the accuracy of different sensor types, addresses calibration issues and retrieval aspects.
Download or read book Temperature Control of Avalanche Photodiode Using Thermoelectric Cooler written by Tamer F. Refaat and published by . This book was released on 1999 with total page 24 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Summaries of Papers Presented at the Conference on Lasers and Electro optics written by and published by . This book was released on 1999 with total page 670 pages. Available in PDF, EPUB and Kindle. Book excerpt:
