Inversion Calculation of Atmospheric Refractive Index Structure Constant Based on Atmospheric Coherence Length and Isoplanatic Angle Measured in Nanshan, Xinjiang

Yuxi Cao; Haifeng Yao; Heng Zhang; Lei Zhang; Shuai Chang; Shoufeng Tong; Xiaoke Tao

doi:10.3788/LOP222937

Abstract

The refractive index structure constant

C_{n}^{2}

is an important atmospheric parameter reflecting turbulence intensity. Herein, a new

C_{n}^{2}

inversion method is proposed based on the coherence length

r_{0}

and isoplanatic angle

θ_{0}

data of the entire atmospheric layer to address the problem related to the fact that many initial input data are needed for inversion and inversion without single type data. Based on the generalized Hufnagel-Valley (HV) turbulence model, the theoretical relationship between

r_{0}

and

θ_{0}

is deduced. Based on the measured data of

r_{0}

and

θ_{0}

in Nanshan, Xinjiang, the seven parameters of the generalized HV model are obtained using inverse calculations followed by the determination of the

C_{n}^{2}

profile. These seven parameter values are substituted into the deduced theoretical relationship of

r_{0}

and

θ_{0}

to calculate the value of

θ_{0}

on any single day. The simulation results show that the variation trend of the fitted average

C_{n}^{2}

and single-day

C_{n}^{2}

profiles are in good agreement with the Xianghe model, and the coincidence degree is high. The average value of the daily correlation coefficient between the calculated and the measured

θ_{0}

profiles reaches 81.95%, and the highest value is 87%. The results verify the feasibility of the proposed method and provide a reference for the inversion of the

C_{n}^{2}

profile.