兰州地区光强分布及其起伏特性研究

发布时间：2018-01-31 21:33

本文关键词： 大气光学大气湍流激光传输光强分布光强起伏闪烁指数概率密度分布　出处：《光子学报》2017年06期 　论文类型：期刊论文

【摘要】：在兰州地区夜间进行了链路长为610m的激光传输实验,研究了高斯激光在不同天气条件下的光强分布及其起伏特性.采用三维伪彩色变换方法,分析了光斑光强的空间分布规律,得到了光斑主瓣光强服从类高斯分布,并按照晴天、多云天、阴天的顺序,光斑几何中心位置附近光强分布的陡峭度依次减小,而其衰减则依次增大的结论.同时,利用实测光强值分析了大气闪烁指数,结果表明:晴天、雨后晴天和阴天下的闪烁指数分别为0.225 4、0.189 2、0.188 8,这说明晴天下的光强起伏大于雨后晴天和阴天的,且均为弱起伏.通过对归一化光强的频数分布进行非线性拟合得到了光强的概率密度分布,它们均服从对数正态分布,其中晴天下的概率密度曲线的拟合优度更是达到了0.997 50.
[Abstract]:A 610m laser transmission experiment was carried out at night in Lanzhou area. The intensity distribution and fluctuation characteristics of Gao Si laser under different weather conditions were studied. Three-dimensional pseudo-color transform method was used. The spatial distribution law of light spot intensity was analyzed, and the distribution of light intensity of light spot main lobe was obtained from Gao Si, and according to the order of sunny day, cloudy day and cloudy day. The conclusion that the intensity distribution near the geometric center of the spot decreases in turn and the attenuation increases in turn. At the same time, the atmospheric scintillation index is analyzed by using the measured light intensity. The results show that it is sunny. The scintillation index of sunny and overcast days after rain is 0.225 4 ~ 0.189 2 ~ 0.188 8, respectively, which indicates that the fluctuation of light intensity in sunny days is larger than that in sunny and cloudy days after rain. The probability density distribution of the light intensity is obtained by nonlinear fitting of the frequency distribution of the normalized light intensity, and they are all obeyed from the logarithmic normal distribution. Among them, the probability density curve under clear weather has a good fitting degree of 0.997 50.
【作者单位】：兰州理工大学计算机与通信学院;
【基金】：国家自然科学基金(Nos.61465007,61265003,61461026) 兰州理工大学博士基金(No.14-0232)资助~~
【分类号】：TN24;TN929.1
【正文快照】： 0　引言激光信号在大气信道中传输时会受到空间损耗、大气衰减、大气湍流和背景辐射等因素的影响,尤其是大气湍流的影响最为明显.大气湍流会造成大气折射率的随机变化,导致激光波阵面畸变,引起光强起伏、光束飘移、光束扩展和光束抖动等现象[1].其中,光强起伏会导致接收信号

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