雾对能见度的影响估算

Estimation of Fog′s Impact on Visibility

由于雾的产生造成的低能见度严重影响了飞机的起飞和着陆,通过分析能见度的微观影响因子得出具体的能见度数学关系式,为后续研究提供依据。通过对雾滴建立模型,即将雾滴看作均匀的球形粒子从几何光学角度分析了能见度降低的原因,用Matlab软件对雾滴谱分布进行拟合。在忽略复折射率和波长影响的情况下,主要考虑雾滴数密度与含水量是主要的影响因子,得出了能见度两种定量关系式。通过比较分析,将雾滴看作大小相同来计算能见度较准确,拟合的雾滴谱分布表明所建立雾滴模型的正确性。

The low visibility can affect the taking off and landing of the aircraft severely due to the fog, the mathematical relationship can be found by analyzing the micro-impact factor, which can supply the basis for the following study. The reason for the reduced visibility is analyzed from the view of geometrical optics by establishing model which regards the droplet of fog as uniform spherical particle, and the distribution of droplet spectrum is fitted using Matlab. Neglecting the impact of the complex refractive index and wavelength, two kinds of quantitative relationship were obtained considering the main affecting factors were number density and water content of the droplet. The more accurate result can be obtained through comparative analysis regarding the size of the droplet as uniformity, and the fitting droplet spectrum shows the model of the droplet is accurate.