Download or read book Coherent Doppler Wind Lidars in a Turbulent Atmosphere written by Viktor Banakh and published by Artech House. This book was released on 2013-09-01 with total page 277 pages. Available in PDF, EPUB and Kindle. Book excerpt: Radiophysical tools for measuring atmospheric dynamics include sodars, Doppler radars, and Doppler lidars. Among these, coherent Doppler lidars (CDLs) have been considered the best for remote measurement of wind turbulence. This is important not only for understanding the exchange processes in the boundary layer, but also in the applied aspect, such as aviation safety. CDLs significantly extend possibilities of experimental investigation of not only wind turbulence, but also coherent structures such as aircraft wake vortices. The authors of this book conducted field tests of the developed methods of lidar measurements of the wind velocity, atmospheric turbulence parameters, and aircraft wake vortices. This valuable resource, containing over 500 equations based on original results from the authors’ work, gives professionals a comprehensive description of the operating principles of continuous wave and pulsed coherent Doppler lidars. This book studies the possibilities of obtaining information about wind turbulence from data measured by continuous wave and pulsed CDLs. The procedures for estimation are described, as well as algorithms for numerical simulation. Results on the vortex behavior and evolution are then presented.
Download or read book Relation of Infrared Doppler Lidar to Remote Wind Measurements in the Turbulent Atmosphere written by and published by . This book was released on 1978 with total page 12 pages. Available in PDF, EPUB and Kindle. Book excerpt: The performance of a coherent Doppler lidar is affected by the atmosphere. Refractive index inhomogeneities limit the effective aperture of our system to 15.5 cm + or - 4% on the average for a 2.6 km horizontal path 2 m above the surface under daytime conditions. Effective aperture scales as range to the -3/5 power. A differential Doppler technique can measure the wind vector in a single atmospheric volume with three (or mor) closely-spaced beams. This method works even when the distribution of velocities in the volume is wider than the velocity separation from beam angle differences. The structure function for backscatter and wind inhomogeneities scales approximately as r to the 2/3 power between the minimum detectable scale in our experiment and an outer scale of 100 to 500 m, depending on atmospheric condition. (Author).
Download or read book Lidar in a Turbulent Atmosphere written by Viktor Arsentʹevich Banakh and published by Artech House Publishers. This book was released on 1987 with total page 208 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 Optimizing Dual Doppler Lidar Measurements of Surface Layer Coherent Structures with Large Eddy Simulations written by Stawiarski, Christina and published by KIT Scientific Publishing. This book was released on 2014-07-10 with total page 262 pages. Available in PDF, EPUB and Kindle. Book excerpt: Coherent structures are patterns in the wind field of the atmospheric boundary layer. The deployment of two scanning Doppler lidars facilitates the measurement of the horizontal wind field, but the inherent averaging processes complicate an interpretation of the results. To assess the suitability of this technique for coherent structure detection large-eddy simulations are used as a basis for virtual measurements, and the effects of the lidar technique on the wind field structure are analyzed.
Download or read book Remote Sensing of Atmospheric Conditions for Wind Energy Applications written by Charlotte Bay Hasager and published by MDPI. This book was released on 2019-05-24 with total page 290 pages. Available in PDF, EPUB and Kindle. Book excerpt: This Special Issue “Atmospheric Conditions for Wind Energy Applications” hosts papers on aspects of remote sensing for atmospheric conditions for wind energy applications. Wind lidar technology is presented from a theoretical view on the coherent focused Doppler lidar principles. Furthermore, wind lidar for applied use for wind turbine control, wind farm wake, and gust characterizations is presented, as well as methods to reduce uncertainty when using lidar in complex terrain. Wind lidar observations are used to validate numerical model results. Wind Doppler lidar mounted on aircraft used for observing winds in hurricane conditions and Doppler radar on the ground used for very short-term wind forecasting are presented. For the offshore environment, floating lidar data processing is presented as well as an experiment with wind-profiling lidar on a ferry for model validation. Assessments of wind resources in the coastal zone using wind-profiling lidar and global wind maps using satellite data are presented.
Download or read book Coherent Doppler LIDAR for Boundary Layer Studies and Wind Energy written by Aditya Choukulkar and published by . This book was released on 2013 with total page 157 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis outlines the development of a vector retrieval technique, based on data assimilation, for a coherent Doppler LIDAR (Light Detection and Ranging). A detailed analysis of the Optimal Interpolation (OI) technique for vector retrieval is presented. Through several modifications to the OI technique, it is shown that the modified technique results in significant improvement in velocity retrieval accuracy. These modifications include changes to innovation covariance portioning, covariance binning, and analysis increment calculation. It is observed that the modified technique is able to make retrievals with better accuracy, preserves local information better, and compares well with tower measurements. In order to study the error of representativeness and vector retrieval error, a lidar simulator was constructed. Using the lidar simulator a thorough sensitivity analysis of the lidar measurement process and vector retrieval is carried out. The error of representativeness as a function of scales of motion and sensitivity of vector retrieval to look angle is quantified. Using the modified OI technique, study of nocturnal flow in Owens' Valley, CA was carried out to identify and understand uncharacteristic events on the night of March 27th 2006. Observations from 1030 UTC to 1230 UTC (0230 hr local time to 0430 hr local time) on March 27 2006 are presented. Lidar observations show complex and uncharacteristic flows such as sudden bursts of westerly cross-valley wind mixing with the dominant up-valley wind. Model results from Coupled Ocean/Atmosphere Mesoscale Prediction System (COAMPS®) and other in-situ instrumentations are used to corroborate and complement these observations. The modified OI technique is used to identify uncharacteristic and extreme flow events at a wind development site. Estimates of turbulence and shear from this technique are compared to tower measurements. A formulation for equivalent wind speed in the presence of variations in wind speed and direction, combined with shear is developed and used to determine wind energy content in presence of turbulence.
Download or read book Tenth Biennial Coherent Laser Radar Technology and Applications Conference written by Michael J. Kavaya and published by . This book was released on 1999 with total page 336 pages. Available in PDF, EPUB and Kindle. Book excerpt: The 10th conference on coherent laser radar technology and applications is the latest in a series beginning in 1980, which provides a forum for exchange of information on recent events, current status, and future directions of coherent laser radar (or lidar or lader) technology and applications. This conference emphasizes the latest advancements in the coherent laser radar field, including theory, modeling, components, systems, instrumentation, measurements, calibration, data processing techniques, operational uses, and comparisons with other remote sensing technologies.
Download or read book Exploratory Meeting on Airborne Doppler Lidar Wind Velocity Measurements written by and published by . This book was released on 1980 with total page 62 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Spatial Variability in Environmental Science written by John P. Tiefenbacher and published by BoD – Books on Demand. This book was released on 2020-10-21 with total page 198 pages. Available in PDF, EPUB and Kindle. Book excerpt: Spatial Variability in Environmental Science - Patterns, Processes, and Analyses includes eight studies that examine the issue of spatial variability in four areas of the environmental sciences – atmospheric science, geological science, biological science, and landscape science. The topics range from monitoring of wind, the urban heat island, and atmospheric pollution, to coastal geomorphology, landscape planning and forest ecology, the problem of introduced species to regional ecologies, and a technique to improve the identification of human constructions in semi-natural landscapes. A small volume can only offer a small glimpse at the activities of scientists and insights into environmental science, but the array of papers herein offers a unique view of the current scholarship.
Download or read book Lidar written by Claus Weitkamp and published by Springer Science & Business. This book was released on 2006-06-03 with total page 467 pages. Available in PDF, EPUB and Kindle. Book excerpt: Written by leading experts in optical radar, or lidar, this book brings all the recent practices up-to-date. With a Foreword by one of the founding fathers in the area. Its broad cross-disciplinary scope should appeal to scientists ranging from the view of optical sciences to environmental engineers. Optical remote sensing has matured to become a lead method for cross-disciplinary research. This new multi-authored book reviews the state-of-the-art in a readable monograph.
Download or read book Atomic and Molecular Spectroscopy written by Sune Svanberg and published by Springer Nature. This book was released on 2023-01-06 with total page 698 pages. Available in PDF, EPUB and Kindle. Book excerpt: A wide-ranging review of modern spectroscopic techniques such as X-ray, photoelectron, optical and laser spectroscopy, and radiofrequency and microwave techniques. On the fundamental side the book focuses on physical principles and the impact of spectroscopy on our understanding of the building blocks of matter, while in the area of applications particular attention is given to those in chemical analysis, photochemistry, surface characterisation, environmental and medical diagnostics, remote sensing and astrophyscis. The Fourth Edition also provides the reader with an update on laser cooling and trapping, Bose-Einstein condensation, ultra-fast spectroscopy, high-power laser/matter interaction, satellite-based astronomy and spectroscopic aspects of laser medicine.
Download or read book Remote Sensing of Turbulence written by Victor Raizer and published by CRC Press. This book was released on 2021-10-03 with total page 273 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book offers a unique multidisciplinary integration of the physics of turbulence and remote sensing technology. Remote Sensing of Turbulence provides a new vision on the research of turbulence and summarizes the current and future challenges of monitoring turbulence remotely. The book emphasizes sophisticated geophysical applications, detection, and recognition of complex turbulent flows in oceans and the atmosphere. Through several techniques based on microwave and optical/IR observations, the text explores the technological capabilities and tools for the detection of turbulence, their signatures, and variability. FEATURES Covers the fundamental aspects of turbulence problems with a broad geophysical scope for a wide audience of readers Provides a complete description of remote-sensing capabilities for observing turbulence in the earth’s environment Establishes the state-of-the-art remote-sensing techniques and methods of data analysis for turbulence detection Investigates and evaluates turbulence detection signatures, their properties, and variability Provides cutting-edge remote-sensing applications for space-based monitoring and forecasts of turbulence in oceans and the atmosphere This book is a great resource for applied physicists, the professional remote sensing community, ecologists, geophysicists, and earth scientists.
Download or read book Evolution Within the Atmospheric Boundary Layer of Coherent Structures Generated by Wind Turbines written by Mithu Debnath and published by . This book was released on 2018 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Wind turbine wakes undergo complex dynamics varying as a function of the incoming wind conditions, which are modulated by the atmospheric static stability and terrain characteristics. Accurate evaluation of the wind velocity components over the rotor disc represent the relevant input for the wind turbine aerodynamics. Power extraction exerted by the turbines on the atmospheric boundary layer leads to the generation of wind turbine wakes, which are flow regions characterized by a velocity deficit and the presence of coherent vorticity structures evolving downstream. Therefore, wind turbulence and dynamics of these vorticity structures produced by utility-scale wind turbines need to be characterized accurately. In this work, a field measurement campaign is described where different remote sensing instruments were assessed to retrieve the wind velocity components with different levels of accuracy. This campaign provided an unique opportunity to retrieve the wind velocity components with different technologies and perform inter-comparison studies in terms of both first and second order turbulent statistics. The results show that Doppler LiDARs have capability to retrieve mean wind speed with high accuracy and turbulent fluctuations with certain limitations. Besides the development of experimental measurement techniques for probing vorticity dynamics within the atmospheric boundary layer, research endeavors were focused in performing analyses based on Proper Orthogonal Decomposition (POD) and Dynamic Mode Decomposition (DMD) to identify coherent structures within wind turbine wakes. Different data-sets, which include Large Eddy Simulation (LES) of single wind turbine with and without tower and nacelle were analyzed. Careful analysis enabled the detection of different instability modes of the helicoidal tip vortices, namely elliptical instability and leap-frogging due to the self rotation and mutual induction among the vortex cores.
Download or read book Optical Engineering written by and published by . This book was released on 2005 with total page 946 pages. Available in PDF, EPUB and Kindle. Book excerpt: Publishes papers reporting on research and development in optical science and engineering and the practical applications of known optical science, engineering, and technology.
Download or read book Trends in Optics written by Anna Consortini and published by Academic Press. This book was released on 1996-08-05 with total page 607 pages. Available in PDF, EPUB and Kindle. Book excerpt: Anna Consortini, The President of the International Commission for Optics (ICO), has accommodated a broad spectrum of optical science topics in Trends in Optics. This book, a compilation of research reviews written by outstanding figures in the field of optics, is aimed not only at specialists in the optical sciences, but also at scientists in other fields who might want to broaden their knowledge of optics. The latest developments in this rapidly progressing field are described, and new applications are detailed--including some previously undisclosed material on the U.S. 'Star Wars project. Authoritative and approachable, this volume should provide comprehensive insight into the ever-expanding optical sciences. Key Features * Edited by the president of the International Commission for Optics * Includes research reviews written by experts in the field * Compiles a wide range of topics in optical science
Download or read book Estimating Atmospheric Boundary Layer Turbulence in the Marine Environment Using Lidar Systems with Applications for Offshore Wind Energy written by Praneeth Gurumurthy and published by . This book was released on 2021 with total page 85 pages. Available in PDF, EPUB and Kindle. Book excerpt: Estimating turbulence in the marine-atmospheric boundary layer is critical to many industrial, commercial and scientific fields, but of particular importance to the wind energy industry. Contributing to both the efficiency of energy extraction and the life-cycle cost of the turbine itself, turbulence in the atmospheric boundary layer is estimated within the wind energy industry as Turbulence Intensity (TI) and more recently by Turbulent Kinetic Energy (TKE). Traditional in-situ methods to measure turbulence are extremely difficult to deploy in the marine environment, resulting in a recent movement to and dependence on remote sensing methods. One type of remote sensing instrument, Doppler lidars, have shown to reliably estimate the wind speed and atmospheric turbulence while being cost effective and easily deployable, and hence are being increasingly utilized as a standard for wind energy assessments. In this thesis, the ability of lidars to measure turbulence up to a height of 200 m above mean sea level in the marine-atmospheric boundary layer was tested using a 7-month data set spanning winter to early summer. Lidar-based TI and TKE were estimated by three methods using observations from a highly validated lidar system and compared under both convective and stable atmospheric stability conditions. Convective periods were found to have higher turbulence at all the heights compared to stable conditions, while mean wind speed and shear were higher during stable conditions. The study period was characterized by generally low turbulent conditions with high turbulence events occurring at timescales of a few days. Mean vertical profiles of TKE were non-uniformly distributed in height during low turbulent conditions. During highly turbulent events, TKE increased more strongly with height. The definition of TI--following the industry or meteorology conventions -- had no real effect on the results, and differences between cup or sonic anemometers and lidar TI values were small except at low wind speeds. All the three lidar-based TKE methods tested corresponded closely to independent estimates, and differences between the methods were small relative to the temporal variability of TKE observed at the offshore site.
