临近空间“空-空”激光通信链路传输特性分析

Analysis on "air-to-air" link transmission characteristic of laser communication in near space

针对临近空间"空-空"激光通信链路的传输特性,进行了较为系统的研究。首先,对比临近空间的"空-地"链路和"空-天"链路,给出了"空-空"链路的大气信道特征:一方面,从大气成分等因素出发,指出了可能造成"空-空"链路大气衰减的3种原因,得到了"空-空"链路的大气衰减信道;另一方面,由相关资料得到"空-空"链路所在空域的大气湍流尺度,再根据大气湍流尺度与激光光束直径的对比关系引发的湍流效应的不同,分析了"空-空"链路的大气湍流信道。其次,重点针对大气湍流效应,进行了仿真计算,得到了光强闪烁方差与通信传输距离、光强闪烁方差与激光波长、到达角起伏方差与传输距离的关系。最后,对计算结果进行了讨论。

The ＂air-to -air＂ link researched systematically. Firstly, the by comparing ＂air-to-ground＂ link atmospheric attenuation channel of transmission characteristic of characteristic of atmospheric laser communication in near space was channel of ＂air-to-air＂ link was given with ＂air-to-space＂ link in near space. On the one hand, the air-to-air＂ link was obtained after analyzing the three causes of the atmospheric attenuation from the standpoint of atmospheric components. On the other hand, the atmospheric turbulence channel of the＂air-to-air＂ link was analyzed on the basis of the relationship among atmospheric turbulence scale, laser beam diameter and turbulence effect. Furthermore, the atmospheric turbulence effect was mainly calculated and the relationship which was between variance of irradiance scintillation and transmission distance, between variance of irradiance scintillation and wavelength, and between the variance of angle-of-arrival fluctuation and transmission distance, was gained through calculation.At last, the calculated result was discussed.