有限外尺度对大气湍流统计特征测量的影响

The Effects of Finite Outer Scale on the Measurement of Characterization of Atmospheric Turbulence Statistics

导出了有限外尺度影响下的相位结构函数和孔径平均的斜率相关函数的表达式 ,结果表明有限的大气外尺度对大气湍流统计特征的测量有很大的影响 ,尤其对大尺寸的望远镜和子孔径更是如此。基于科尔莫戈罗夫模型的大气相位结构函数和相干长度仅仅是本文推导结果的近似。对结果的分析表明 ,测量得到的对大气湍流科尔莫戈罗夫模型的偏离有可能是大气外尺度的影响 。

Phase structure function and aperture averaged slope correlation function with finite outer scale are derived. The strong effects of finite outer scale on measurement of characterization of atmospheric turbulence statistics are shown, especially for large size telescope and subaperture. The phase structure function and atmospheric coherent length based on Kolmogorov model is just the proximation of the formalism derived here. The analysis indicates that it can not be determined whether the deviation from the model of Kolmogorov turbulence is caused by real variance of spectrum or by the effect of finite outer scale.