激光大气闪烁的分形分析

 采用分形理论分析了激光大气闪烁的统计特征。研究结果表明：在弱起伏条件下，激光大气闪烁的分形维和奇异性随光强起伏的增强而增大，而其长期相关性则减小；不同Fresnel尺度下具有相同闪烁指数的激光大气闪烁的分形特征存在着明显的差别；在强起伏条件下，有限的数据中尚未发现分形维有饱和现象，因此可以用来描述激光大气闪烁的强度。

Fractal characteristics of laser scintillation in the atmosphere

Laser scintillation in the turbulent atmosphere was analyzed using the fractal methods, especially its fractal dimension and Hurst exponent. The results show that: the laser scintillation is a nonstationary random process with long-run and positive correlation. In the weak fluctuation conditions (the scintillation index in the range of 0 to 1.2), the fractal dimension would increase and the Hurst exponent would decrease with the increase of the scintillation index. That means the scintillation's intensity and complexity both increase and the temporal correlation decreases as the degree of fluctuation increases. In the strong fluctuation conditions, the limited data may reflect that the fractal dimension keeps on increasing, and no saturation appears. In addition, the effect of the Fresnel zone to the scintillation was also studied in the paper and some new results is obtained.