A Model of Topographic Correction and Reflectance Retrieval for Optical Satellite Data in Forested Areas

Topographic correction is a necessary step of pre-process in the remote sensing application in rugged terrain. Most of traditional topographic correction methods are empirical and statistical based. These methods have the advantage of facility; however they also have some disadvantages, such as lack of comprehensive physical analysis, subjectivity in operation, separation of atmospheric correction and so on. Instead, the topographic correction model based on radiative transfer theory can overcome these disadvantages in a degree. In this paper, an optical, radiative transfer theory based model for topographic correction and surface reflectance retrieval for forested terrain is developed. This model is established by modifying existing radiative transfer theory based model (developed by Sandmeier et al). The difference between the two models is that the modified model is developed in sub-pixel scale, which SCS correction is also based on. Finally, the model is validated using the ETM imagery and DEM of Lipin County, Guizhou province, China. Visual and statistical methods are used to evaluate the results of the two models. In comparison with existing radiative transfer theory based model, the modified model has a better result in removing the terrain effects of imagery in forested areas. ∗ Corresponding author: E-mail: [email protected]