光学学报, 2009, 29 (1): 114, 网络出版: 2009-02-10
基于畸变相位波前分形特征产生矩形湍流相屏
Generation of Rectangular Turbulence Phase Screens Based on Fractal Characteristics of Distorted Wavefront
大气光学 湍流相位屏 分形插值 大气湍流 数值模拟 atmospheric optics turbulent phase screen fractal interpolation atmospheric turbulence numerical simulation
摘要
在包含时间进程的光波大气传输及其自适应光学相位校正的数值模拟研究中, 如长曝光成像和自适应光学系统的动态控制过程, 矩形湍流相屏的产生和应用尤为重要。而现在通常使用的功率谱反演法产生的是正方形的湍流相屏, 只采用其中的矩形部分显然造成计算机资源的浪费; 并且谱反演法产生的湍流相屏需要进行低频补偿, 从而明显地增加计算量。基于大气湍流所造成的畸变相位波前的分形特征, 提出了一种产生矩形湍流相屏的新方法, 并与解析理论结果进行对比, 验证了这种矩形相屏产生方法的正确性。与已有的方法相比, 此算法具有两个明显的优点:算法简单、计算效率高, 节省计算机资源; 与大气湍流介质统计特性无论在高频部分还是在低频部分均符合得较好。
Abstract
In numerical simulation of light propagation through the atmosphere with the phase compensation by an adaptive optical system including temporal evolution, such as very long exposure imaging and simulation of the dynamic control process in an adaptive optical system, the generation and application of rectangular turbulence phase screens are critical. But the widely-used spectral approach can only generate square phase screen, and wastes the computational resource because only a rectangular portion of the square phase screen is practically utilized. Furthermore, the spectral phase screen needs low-frequency modification, so that needs more computation. Based on the fractal characteristics of turbulence-distorted wavefront, a new algorithm for generating rectangular turbulent phase screen is proposed. The phase structure function of generated phase screens agrees well with the theoretical one. Compared with existing approaches, the present algorithm shows obvious advantages: simplicity, high efficiency and less computation resource. The generated phase screen agrees with theoretical results from turbulent statistical characteristics, in the low- and high-frequency region.
吴晗玲, 严海星, 李新阳, 李树山. 基于畸变相位波前分形特征产生矩形湍流相屏[J]. 光学学报, 2009, 29(1): 114. Wu Hanling, Yan Haixing, Li Xinyang, Li Shushan. Generation of Rectangular Turbulence Phase Screens Based on Fractal Characteristics of Distorted Wavefront[J]. Acta Optica Sinica, 2009, 29(1): 114.