光束抖动频谱遥感大气湍流外尺度的理论与实验

本文在微扰理论的基础上导出了高斯光束抖动归一化频谱的普遍表达式和准直光束、球面波光束在均匀光路条件下的分析表达式。计算表明这些频谱中存在一个与湍流外尺度、横截风速有确定关系的峰值频率。我们根据这个特征利用大气相干长度测量仪进行了湍流外尺度的遥感实验，与此同时用五台三杯风速计测量了光路中的平均风速。实验结果指出，离地面８ｍ高度上的湍流外尺度在２．６－７．０ｍ之间变化，平均值为４．９ｍ

THE THEORY AND EXPERIMENT OF REMOTE SENSING OF ATMOSPHERIC TORRENT EXTERNAL SIZE BY LIGHT BEAM VIBRATION FREQUENCY SPECTRUM

Based on perturbation theory this paper gives a general expression for the reduced spectrum of Gauss light beam vibration and an analytic one for collimated light beam and spherical wave light beam under condition of even light path.Calculation indicates that in the spectra there exists a peak frequency definitely related to torrent external size and cross sectional wind rate,on which an atmospheric coherent length measuring apparatus is used for remote sensing experiment of torrent external size,simutaneously five three-cup wind rate meters are employed to measure the mean wind rate on light path .The result shows that at a height of 8m the torrent external size varies from 2.6m to 7.0m, 4.9m in average