Measuring inner scale and structure constant of atmospheric turbulence in a simple way

1990 ◽  
Author(s):  
Anna Consortini ◽  
Yi Yi Sun ◽  
Zhi Ping Li ◽  
Giuliano Conforti
Keyword(s):  
Atmospheric Turbulence ◽  
Structure Constant ◽  
Inner Scale

scholarly journals Method for Measuring the Second-Order Moment of Atmospheric Turbulence

Atmosphere ◽  
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.

scholarly journals Joint measurements of optical parameters by irradiance scintillation and angle-of-arrival fluctuations

Open Physics ◽  
2018 ◽  
Vol 16 (1) ◽  
pp. 387-393
Author(s):  
Chao Gao ◽  
Haodong Liang ◽  
Xiaofeng Li
Keyword(s):  
Error Analysis ◽  
Atmospheric Turbulence ◽  
Power Law ◽  
Structure Constant ◽  
Simultaneous Equations ◽  
Scintillation Index ◽  
Optical Parameters ◽  
Angle Of Arrival ◽  
Power Law Exponent

AbstractA method for joint measuring the power law exponent and the structure constant of atmospheric turbulence is proposed and examined. The measurements are equivalent to solve the simultaneous equations formed by the irradiance scintillation index and the angle-of-arrival fluctuations variance, where the measured parameters are regarded as the unknowns. The measured error analysis is also presented. Based on our proposed method, the measured results accord with the daily trend of atmospheric turbulence.

scholarly journals Propagation Properties of an Astigmatic Cos-Gaussian Beam through Turbulent Atmosphere

2021 ◽  
Vol 299 ◽  
pp. 02003
Author(s):  
Kaicheng Zhu ◽  
Xiaolei Ma ◽  
Chang Gao ◽  
Dengjuan Ren ◽  
Jie Zhu
Keyword(s):  
Gaussian Beam ◽  
Atmospheric Turbulence ◽  
Intensity Distribution ◽  
Turbulent Atmosphere ◽  
Structure Constant ◽  
Propagation Distance ◽  
Turbulent Structure ◽  
Fresnel Integral ◽  
Propagation Properties ◽  
Distribution Behaviour

We use the extended Huygens-Fresnel integral to investigate the propagation properties of a cos-Gaussian beam (cosGB) with astigmatism in atmospheric turbulence. The intensity distribution behaviour along the propagation distance for an astigmatic cosGB in atmospheric turbulence are analytically and numerically demonstrated. Some novel phenomena are presented graphically, indicating that the intensity distribution and the on-axial intensity closely depend on the astigmatic parameter and the turbulent structure constant of the cosGBs in the atmospheric turbulence.

Measuring inner scale of atmospheric turbulence by angle of arrival and scintillation

2003 ◽  
Vol 216 (1-3) ◽  
pp. 19-23 ◽  
Author(s):  
A. Consortini ◽  
Yi Yi Sun ◽  
C. Innocenti ◽  
Zhi Ping Li
Keyword(s):  
Atmospheric Turbulence ◽  
Angle Of Arrival ◽  
Inner Scale

scholarly journals Modulation Transfer Function of a Gaussian Beam Based on the Generalized Modified Atmospheric Spectrum

2016 ◽  
Vol 2016 ◽  
pp. 1-8 ◽  
Author(s):  
Chao Gao ◽  
Xiaofeng Li
Keyword(s):  
Transfer Function ◽  
Gaussian Beam ◽  
Atmospheric Turbulence ◽  
Modulation Transfer Function ◽  
Spectral Power ◽  
Optical Parameters ◽  
Modulation Transfer ◽  
Negative Effects ◽  
Kolmogorov Turbulence ◽  
Inner Scale

This paper investigates the modulation transfer function of a Gaussian beam propagating through a horizontal path in weak-fluctuation non-Kolmogorov turbulence. Mathematical expressions are obtained based on the generalized modified atmospheric spectrum, which includes the spectral power law value of non-Kolmogorov turbulence, the finite inner and outer scales of turbulence, and other optical parameters of the Gaussian beam. The numerical results indicate that the atmospheric turbulence would produce less negative effects on the wireless optical communication system with an increase in the inner scale of turbulence. Additionally, the increased outer scale of turbulence makes a Gaussian beam influenced more seriously by the atmospheric turbulence.

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