基于差分像运动法的机载平台大气湍流参数测量

Measurement of Atmospheric Turbulence Parameters on Airborne Platform Based on Differential Image Motion Method

大气湍流参数是评价大气信道对空间激光通信系统性能影响的重要依据。根据机载平台的运动特点,采用差分像运动法并利用夏克-哈特曼传感器与指向、捕获、跟踪伺服单元等设备,在加格达奇地区开展了不同海拔高度下大气湍流参数的分层测量实验。结果表明,在Kolmogorov湍流条件下,该地区日间大气湍流强度随海拔高度的增加而减弱,并在该变化趋势上叠加了大气湍流强度的随机起伏;大气覆盖逆温层顶层海拔高度范围为2.2~2.8km,海拔高度为3.5km的大气相干长度的变化范围为10~26cm。该研究为机载激光通信系统的性能分析提供了重要的参考。

Atmospheric turbulence parameters are the important bases to evaluate the effect of atmospheric channel on space laser communication system performance. According to the motion characteristic of airborne platform, the atmospheric turbulence parameter stratified measurement experiments are carried out at different altitudes in Jagdaqi area with the differential image motion method, and these experiments are combined with Shack-Hartmann sensor and pointing, acquisition, tracking servo units. Results show that the daytime atmospheric turbulence intensity in this region reduces with the increase of altitude, and random fluctuation of atmospheric turbulence intensity is superimposed on the changing trend under the condition of Kolmogorov turbulence. The range of top layer altitude of atmospheric capping inversion layer is 2.2- 2.8 km. At the altitude of 3.5 km, the atmospheric coherence length varies from 10 cm to 26 cm. The study provides an important reference for the performance analysis of airborne laser communication system.