近地光学湍流对于目视进近的影响研究

目视飞行程序中,近地面大气光学湍流会造成大气折射率的起伏进而对于目视进近产生影响.采用了Monin-Obk-hov相似理论,结合机场跑道环境改进了Thiermann-Kohnle模型,并对于大气折射率结构常数进行了数值分析,同时根据机场跑道大气折射率分布,建立简化模型,利用光线的折射理论,估算出了光线弯曲的角度偏差.结论表明,温度波动会造成近地面光学湍流产生,其所引起的角度偏差对于目视进近影响不可被忽略,对于目视进近具有指导意义.

The Research On Visual Approach Under The Affects Of Surface Optical Turbulence

In the VFR procedures, atmospheric optical turbulence near the ground caused by temperature fluctuations will finally lead to the fluctuations of atmosphere refractive which will influence the visual approach in turn. Thiermann-Kohnle model has been improved according to the combination of Monin-Obkhov similar theory and runway environment. the numerical analysis of atmospheric refractive index structure parameter also has been finished. in addition, simplified model has been established based on the atmospheric refractive index distribution of airport runway. finally, according to the theory of light refraction, the angular deviation of the light has been estimated. Conclusion shows that the temperature fluctuations can cause the surface optical turbulence generation and the visual angle deviation cannot be ignored which has a guiding significance for visual approach.