Atmospheric-Turbulence-Degraded Astronomical Image Restoration by Minimizing Second-Order Central Moment

2012 ◽  
Vol 9 (4) ◽  
pp. 672-676 ◽  
Author(s):  
Luxin Yan ◽  
Mingzhi Jin ◽  
Houzhang Fang ◽  
Hai Liu ◽  
Tianxu Zhang
Keyword(s):  
Image Restoration ◽  
Atmospheric Turbulence ◽  
Central Moment ◽  
Second Order ◽  
Astronomical Image

Defocus blurred image restoration by minimizing second-order central moment

2011 ◽  
Author(s):  
Sheng Zhong ◽  
Mingzhi Jin ◽  
Luxin Yan ◽  
Tianxu Zhang
Keyword(s):  
Image Restoration ◽  
Central Moment ◽  
Second Order ◽  
Blurred Image

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.

Astronomical image restoration based on maximum-likelihood incorporated parameter estimation

2013 ◽  
Vol 21 (11) ◽  
pp. 2943-2950 ◽  
Author(s):  
耿则勋 GENG Ze-xun ◽  
魏小峰 WEI Xiao-feng ◽  
沈忱 SHEN Chen
Keyword(s):  
Parameter Estimation ◽  
Maximum Likelihood ◽  
Image Restoration ◽  
Astronomical Image
Sign in / Sign up

Export Citation Format

Share Document