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    • 摘要: 设计了两束正交激光束光斑漂移的实时影像记录系统,进行了一系列的激光束大气传输外场实验,对比研究大气湍流环境下两正交方向激光束的光斑漂移,反演研究大气湍流的各向异性。实验结果表明,近地面大气湍流具有各向异性且表现为:一、与风向相关,当激光传输路径与风向夹角很小时,其垂直和水平方向的光斑漂移量会出现较大的差异,当激光传输路径与风向正交时,其垂直和水平方向光斑漂移量基本一致。二、与实时气温相关,表现为两正交激光束的光斑漂移量统计值在垂直和水平方向的四个分量中的不均匀分配,且气温降低会使不均匀分配的强度增加。分析研究成果,本文提出大气湍流各向异性强度指数A的概念,该指数的大小可以综合性的表征大气湍流各向异性特征及其强度。

       

      Abstract: A real-time image recording system was designed to record spot wander formed by two orthogonal laser beams, and a series of laser beam atmospheric transmission field experiments were conducted to compare the spot wander and study atmospheric turbulence’s anisotropy by inversion. The experimental results show that the atmospheric turbulence near the ground is anisotropic which can be manifested as follows: 1) It is related to the wind direction. A significant difference between vertical wander and horizontal was recorded when the angle between the transmission path and the wind direction was small. When the laser transmission path is orthogonal to the wind direction, vertical wander is basically the same as the horizontal. 2) It is related to real-time temperature. Among the four wander components of two orthogonal laser beams, an uneven distribution of spot wander was found, and temperature decrease increases the intensity of the uneven distribution. Based on the comprehensive analysis of research results, this paper proposes a concept named atmospheric turbulence anisotropy intensity index A which can quantify characteristics and intensity of atmospheric turbulence’s anisotropy.