旋转相位屏模拟大气湍流时空特性的测量

Measurement of Temporal and Spatial Characteristics of Atmospheric Turbulence Simulated by a Rolling Phase Screen

利用一个高速多单元哈特曼传感器对旋转相位屏模拟大气湍流的空间特性和时间特性进行了研究。空间特性方面,计算了湍流的大气相干长度和波面的相位空间结构函数,对比了波前的Zernike系数方差分布。时间特性方面,测量了模拟湍流的Greenwood频率和时间功率谱,并提出了一种新的计算时间常数的方法——残差均方值法。结果表明旋转相位屏模拟的大气湍流符合Kolmogorov湍流统计理论。

Using high-speed, multi-cell Shack-Hartman wave-front sensor, the measurement of temporal and spatial feature to a rolling phase screen laboratory atmospheric turbulence generator is presented. In terms of spatial feature, coherence length of the atmospheric turbulence and phase spatial structure function of the wave-front are calculated, and the variance distribution of the wave-front Zernike coefficient is compared to the theory as well. In addition,on the temporal feature, the Greenwood frequency and time power spectrum of the simulated turbulence are analyzed, A new method that is called residual variance algorithm to calculate the time constant is proposed. The result shows that the atmospheric turbulence generated by the rolling phase screen is consistent with the Kolmogorov turbulence.