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

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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Large Aperture Laser Scintillometer for Measuring the Refractive Index Structure Constant of Atmospheric Turbulence

Chinese Journal of Lasers ◽

10.3788/cjl20083506.0898 ◽

2008 ◽

Vol 35 (6) ◽

pp. 898-902 ◽

Cited By ~ 1

Author(s):

马晓珊 Ma Xiaoshan ◽

朱文越 Zhu Wenyue ◽

饶瑞中 Rao Ruizhong

Keyword(s):

Refractive Index ◽

Atmospheric Turbulence ◽

Structure Constant ◽

Index Structure ◽

Large Aperture

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Experimental validation and design feasibility of a compact interferometric refractive index structure constant measurement sensor for atmospheric turbulence characterization

Laser Communication and Propagation through the Atmosphere and Oceans X ◽

10.1117/12.2594129 ◽

2021 ◽

Author(s):

Jay Land ◽

Daniel Whitley

Keyword(s):

Refractive Index ◽

Atmospheric Turbulence ◽

Experimental Validation ◽

Structure Constant ◽

Index Structure ◽

Measurement Sensor ◽

Constant Measurement

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Derivation of Clear-Air Turbulence Parameters from High-Resolution Radiosonde Data

Journal of Atmospheric and Oceanic Technology ◽

10.1175/jtech-d-16-0046.1 ◽

2017 ◽

Vol 34 (2) ◽

pp. 277-293 ◽

Cited By ~ 6

Author(s):

E. Martini ◽

A. Freni ◽

F. Cuccoli ◽

L. Facheris

Keyword(s):

Refractive Index ◽

High Resolution ◽

Potential Temperature ◽

Structure Constant ◽

Thin Layers ◽

Index Structure ◽

Radiosonde Data ◽

Atmospheric Conditions ◽

Air Turbulence ◽

The Impact

AbstractThe knowledge of atmospheric refractive index structure constant () profiles is fundamental to determine the intensity of turbulence, and hence the impact of the scintillation impairment on the signals propagating in the troposphere. However, their relation with atmospheric variables is not straightforward, and profiles based on statistical considerations are normally employed. This can be a shortcoming when performing simulations for which scintillation disturbances need to be consistent with the assumed atmospheric conditions. To overcome this limitation, this work describes a procedure to obtain an estimate of the refractive index structure constant profile of clear-air turbulence under given atmospheric conditions. The procedure is based on the application of the vertical gradient approach to high-resolution radiosonde data. Since turbulence is known to be confined to vertically thin layers, a preliminary identification of turbulent layers is required. This is accomplished by analyzing the profiles of the Richardson number. The value of the outer scale length is estimated using the Thorpe length calculated from the potential temperature profile. The procedure is applied to high-resolution radiosonde data that have been acquired from the Stratosphere–Troposphere Processes and their Role in Climate (SPARC) Data Center, and the obtained results are consistent with measured profiles previously published in the literature.

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Prediction of atmospheric turbulence refractive index structure constant based on deep learning

24th National Laser Conference & Fifteenth National Conference on Laser Technology and Optoelectronics ◽

10.1117/12.2583944 ◽

2020 ◽

Author(s):

Ma Shengjie ◽

Hao Shiqi ◽

Zhao Qingsong ◽

Xu chenlu ◽

Xiao Junling

Keyword(s):

Refractive Index ◽

Deep Learning ◽

Atmospheric Turbulence ◽

Structure Constant ◽

Index Structure

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Method for Measuring the Second-Order Moment of Atmospheric Turbulence

Atmosphere ◽

10.3390/atmos12050564 ◽

2021 ◽

Vol 12 (5) ◽

pp. 564

Author(s):

Hong Shen ◽

Longkun Yu ◽

Xu Jing ◽

Fengfu Tan

Keyword(s):

Atmospheric Turbulence ◽

Weighting Function ◽

Structure Constant ◽

Turbulence Models ◽

Second Order ◽

Index Structure ◽

Order Moment ◽

Site Testing ◽

Optical Effects ◽

Novel Method

The turbulence moment of order m (μm) is defined as the refractive index structure constant Cn2 integrated over the whole path z with path-weighting function zm. Optical effects of atmospheric turbulence are directly related to turbulence moments. To evaluate the optical effects of atmospheric turbulence, it is necessary to measure the turbulence moment. It is well known that zero-order moments of turbulence (μ0) and five-thirds-order moments of turbulence (μ5/3), which correspond to the seeing and the isoplanatic angles, respectively, have been monitored as routine parameters in astronomical site testing. However, the direct measurement of second-order moments of turbulence (μ2) of the whole layer atmosphere has not been reported. Using a star as the light source, it has been found that μ2 can be measured through the covariance of the irradiance in two receiver apertures with suitable aperture size and aperture separation. Numerical results show that the theoretical error of this novel method is negligible in all the typical turbulence models. This method enabled us to monitor μ2 as a routine parameter in astronomical site testing, which is helpful to understand the characteristics of atmospheric turbulence better combined with μ0 and μ5/3.

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