Study in Retrieval Visibility and Optical Thickness of Fog with MODTRAN

In recent years, many scientists have done some work in monitoring the fog, and achieved fruitful results. Now we want to conduct more in-depth study. In this paper, we utilize MODTRAN to simulate the relationship between transmittance and visibility, height of fog. By fitting the relationship between them, we get the formula that calculates visibility of fog using transmittance and height of fog. The correlation coefficient of this formula is very high, so it can be regarded as an accuracy one. The height of fog can be calculated by top temperature of fog, surface temperature and vertical lapse rate. The transmittance of the fog can be measured by using special instrument. Therefore, the visibility and optical thickness can be retrieved by this method.