An Optical Inversion Technique To Remotely Sense Atmospheric Turbulence Spectra, C 2 n Profiles And Cross-Wind Velocity

1986 ◽  
Author(s):  
Robert M. Manning
Keyword(s):  
Atmospheric Turbulence ◽  
Wind Velocity ◽  
Turbulence Spectra ◽  
Inversion Technique ◽  
Remotely Sense

scholarly journals Cross-contamination effect on turbulence spectra from Doppler beam swinging wind lidar

2020 ◽  
Vol 5 (2) ◽  
pp. 519-541 ◽  
Author(s):  
Felix Kelberlau ◽  
Jakob Mann
Keyword(s):  
Wind Velocity ◽  
Time Lag ◽  
Turbulence Models ◽  
Horizontal Wind ◽  
Cross Contamination ◽  
Turbulence Spectra ◽  
Contamination Effect ◽  
Turbulence Velocity ◽  
Wind Lidar ◽  
Velocity Spectra

Abstract. Turbulence velocity spectra are of high importance for the estimation of loads on wind turbines and other built structures, as well as for fitting measured turbulence values to turbulence models. Spectra generated from reconstructed wind vectors of Doppler beam swinging (DBS) wind lidars differ from spectra based on one-point measurements. Profiling wind lidars have several characteristics that cause these deviations, namely cross-contamination between the three velocity components, averaging along the lines of sight and the limited sampling frequency. This study focuses on analyzing the cross-contamination effect. We sample wind data in a computer-generated turbulence box to predict lidar-derived turbulence spectra for three wind directions and four measurement heights. The data are then processed with the conventional method and with the method of squeezing that reduces the longitudinal separation distances between the measurement locations of the different lidar beams by introducing a time lag into the data processing. The results are analyzed and compared to turbulence velocity spectra from field measurements with a Windcube V2 wind lidar and ultrasonic anemometers as reference. We successfully predict lidar-derived spectra for all test cases and found that their shape is dependent on the angle between the wind direction and the lidar beams. With conventional processing, cross-contamination affects all spectra of the horizontal wind velocity components. The method of squeezing improves the spectra to an acceptable level only for the case of the longitudinal wind velocity component and when the wind blows parallel to one of the lines of sight. The analysis of the simulated spectra described here improves our understanding of the limitations of turbulence measurements with DBS profiling wind lidar.

Boundary Layer Wind Characteristics over Urban Area

2014 ◽  
Vol 501-504 ◽  
pp. 2297-2300
Author(s):  
Lun Hai Zhi
Keyword(s):  
Boundary Layer ◽  
Wind Speed ◽  
Urban Area ◽  
Atmospheric Turbulence ◽  
Wind Velocity ◽  
Three Dimensional ◽  
Tall Buildings ◽  
Gust Factor ◽  
Mean Wind Speed ◽  
Wind Characteristics

This paper presents statistical analysis results of wind speed and atmospheric turbulence data measured from a meteorological station in Beijing and is primarily intended to provide useful information on boundary layer wind characteristics for wind-resistant design of tall buildings and high-rise structures. Wind velocity data in longitudinal, lateral and vertical directions, which were recorded from an ultrasonic anemometer during windstorms, are analyzed and discussed. Atmospheric turbulence information such as turbulence intensity, gust factor, turbulence integral length scale and power spectral densities of the three-dimensional fluctuating wind velocity are presented and used to evaluate the adequacy of existing theoretical and empirical models. The objective of this study is to investigate the profiles of mean wind speed and atmospheric turbulence characteristics over a typical urban area.

scholarly journals Energy Spectra of Atmospheric Turbulence for Calculating Cn2 Parameter. I. Maidanak and Suffa Observatories in Uzbekistan

Atmosphere ◽  
2021 ◽  
Vol 12 (12) ◽  
pp. 1614
Author(s):  
Artem Yu. Shikhovtsev ◽  
Pavel G. Kovadlo ◽  
Evgeniy A. Kopylov ◽  
Mansur A. Ibrahimov ◽  
Shuhrat A. Ehgamberdiev ◽  
...  
Keyword(s):  
Refractive Index ◽  
Atmospheric Turbulence ◽  
Baroclinic Instability ◽  
Structure Constant ◽  
Index Structure ◽  
Energy Spectra ◽  
Atmospheric Conditions ◽  
Astronomical Observations ◽  
Turbulence Spectra ◽  
Wide Range

Knowledge of the turbulence spectra is of interest for describing atmospheric conditions as applied to astronomical observations. This article discusses the deformations of the turbulence spectra with heights in a wide range of scales at the sites of the Maidanak and Suffa observatories. It is shown that the energy of baroclinic instability is high at the sites of these observatories and should be taken into account in the calculations of the refractive index structure constant Cn2.

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