对太阳直射、天空满散射和邻近地形的反射辐射进行了较为详细的分析,提出了崎岖山地真实反射率的恢\n复模型及相应的快速算法,从而实现了消除山地卫星影像中地形的影响,恢复阴影所包含的细节.利用TM影像的实验表明,此方法可以有效地实现对影像的订正,为遥感图象的后处理提供更多的信息.

Topographic effects are the main obstacles to further application of remotely sensed images. Due to the fact of that different slopes and aspects show very different brightness in images even if the ground cover is the same type, the general classification methods may give wrong results. How to remove the topographic effects is a necessary step in quantitative remote sensing. However, topographic effects are very complex and difficult to be removed successfully. Based on detailed analysis of illumination sources that include solar direct irradiance, sky diffuse irradiance and adjacent reflectance, this paper presents a reflectance retrieval model to remove the topographic effects in satellite images and retrieve the information contained in shadow areas. From the corrected TM images, it is found that the topographic effects are removed effectively. This just illustrates that this method can provide more information for post processing of the remotely sensed images.