A Research of Split Window Algorithm Based on MODIS Image Data and Parameter Determination

Split-window algorithm is the main method to retrieve the LST by thermal infrared data. In this paper, we deduce a new Split-window algorithm which can be used to retrieve LST by using MODIS data on the basis of the common form of split window algorithm. Land surface emissivity and atmospheric transmittance are the two key parameters which are used to retrieve LST. As MODIS image has the lower resolution and vegetation, soil and water are the main three ingredients for MODIS image, we can estimate the land surface emissivity according to the ratio of three ingredients. We can estimate the atmospheric transmittance on the basis of the relationship between atmospheric transmittance and water content. At last we use this new Split-window algorithm to retrieve LST in JiangSu, and the graph of LST indicate the space difference, urban heat islaud effect and different ground object types.