Topographic Correction

Topographic correction is an enhancement procedure of remote sensing images that minimizes radiometric differences caused by the influence of elevation and slope of the terrain and solar radiation conditions. If the relief is uneven, shadows and brightness variations appear, and the same land-use types may look different in two different satellite images. The application of topographic correction allows us to achieve consistency in illumination impacts and consistent surface reflectance data. It is widely used in satellite image processing, GIS, vegetation mapping, forest monitoring, land cover classification, terrain analysis, and monitoring of environmental conditions. Topographic correction is performed with the help of satellite images and digital elevation model (DEM) which provides information about the influence of the terrain and solar angles. Such methods as Cosine correction, C-correction, and Minnaert correction may be used for enhancing the quality of satellite images and consequently making geospatial calculations more trustworthy, especially in the mountains and regions with uneven relief.