Retrieval Of Property Parameters From Land Radiation Fog Based On MODIS Image In Daytime And Analysis Of Dynamic Change

As a kind of common atmospheric disaster, fog disaster has seriously affected people’s daily traveling and body health. Land radiation fog is one kind with the highest frequency, it has the feature of long persistence and large scale influence. Traditional method to monitor fog is to collect the meteorological parameters from ground meteorological station in fog region and give a statistic and analysis. With the development of remote sensing, MODIS image from satellite can be used to detect fog and monitor fog, overcoming the lack of density of ground meteorological station. At the same time, we can retrieve the property parameters quantitatively. This parameters reflect indirectly the distribution and development of fog. If we compare the ground data to retrieved result, the method can be judged to be feasible.The thesis choose the land radiation fog in stable phase which happened in North China at13:10on November24th2007as research object, using the MODISL1B image which contains fog to undergo the data preprocess and fog detection, then retrieve the optical thickness、 vertical thickness、visibility、liquid water content、effective particle radius based on the establishment of path model of radiative transfer and property parameter algorithm, contrasting three methods in retrieving vertical thickness and choose the suitable one called H method. At last, linear regression analysis can be used to compare the ground visibility data with the retrieved visibility, the correlation coefficient is0.9366, and the slope is1.0205. it indicates the retrieved result close to ture value, the method is feasible. On the basis of research above, ten MODIS time series image which contains one fog process happened in Beijing region from January10th to14th2013are chosen to retrieve the visibility、liquid water content、effective particle radius, then analyse dynamic change condition of average value with the time, summarizing the phase feature of this three property parameters in fog process. At the same time, we can create the relationship between four factor of influence such as NDVI、 DEM、brightness temperature、use of land and the distribution of property parameters in stable phase, then analyse every factor of influence which contributes to distribution and development of fog disaster.