The Inversion Of The Content Of Atmospheric Water Vapor Based On RS Images

The water vapor in the atmosphere is the most active component, and it is not only the necessary requirement of the forming of rain cloud as well as the vinculum of the materials and energy transmission of the earth-atmosphere system. And it is not the essential parameter in the foreseeing of rain and other disasters. And even more important, it is an element for the researching of the global water cycling, climate changes and the energy cycling of the earth-atmosphere system.Firstly, the paper describes the channels of the MODIS images basing on the current existing methods of retrieving the atmospheric water vapor. The content of the atmospheric water vapor is attained by MODTRAN simulation. The main channels of MODIS used for the retrieval of the atmospheric water vapor are 2, 5, 17, 18 and 19, the central locations of which are respectively 860,905,936,940 and1240 nanometer. Among them, the first three ones are water-vapor-absorption bands and the others are atmosphere windows. The band-ratio method is used to partly eliminate the impacts of ground reflectance and other components in the atmosphere in retrieving atmospheric water vapor. We build a look-up table between the water vapor and the atmospheric transmittance by using MODTRAN. The error of the result fluctuates around the 10 percents.Then, the paper discusses the theory and process of the atmospheric water vapor using HJ-HSI images. And, through convincing practices, we come up with that it is very successful to retrieve the content of the atmospheric water vapor using HJ-HSI images.