大气相干长度是评价激光传输系统自适应相位校正效果的重要参数,因此对大气相干长度进行测量分析具有实际应用价值。设计并搭建了一种基于差分像运动法测量大气相干长度的光学系统,并进行了外场实验,分析了西安地区全天范围内大气相干长度的变化趋势。结果表明,虽然在不同方向上测量的大气相干长度值有所不同,但总体变化趋势一致,且夜晚变化较白天更为稳定。本文结果为研究城市无线光通信系统提供了一定的参考。

Atmospheric coherence length is an important parameter for evaluating the effect of adaptive phase correction in a laser transmission system, so there is a high research value to measure and analyze the atmospheric coherence length. In this paper, a system for measuring atmospheric coherence length by differential image motion method is designed and built to carry out field experiments in Xi'an area, and the variation trend of atmospheric coherence length within the whole day in Xi'an area is analyzed. Results show that although the values of atmospheric coherence length measured in different directions are different, the overall variation trend is the same, and the variation is more stable at night than at day. These results have a reference value for the construction of urban wireless optical transmission systems.