Topographic correction of hyperspectral data of west east-Azarbayjan

In this study the effect of topographic correction has been investigated on the Hyperion dataset of west of east-Azarbayjan. Regarding to the growing role of the application of the hyperspectral data in detection of earth features، in order ofdue to its higher resolution and more accurate performance، the reliable corrections is necessary to achieve accurate outcomes. The topographic correction as a preprocessing method is a significant correction in the mountainous regions in remote sensing studies. It aims to elimination ofeliminate the topographic effect of earth surface in recorded energy at the sensors. This correction is necessary because since the dips of different parts of study area (image pixels) differ and then the intensity of recorded radiance will be affected. In this study the dataset was first atmospherically corrected and then the noisy bands were deleted by signal to noise ratio computation and visual survey of bands. Finally the topographic correction was performed by using of the Lambertian method in IDL and was applied on the dataset. In the next step tree pixels were selected of from the study studied region with different dips and azimuths to evaluate the performance of correction by comparing the spectral profiles of them، before and after correction. The findings showed athe decreaseing in diversity of false illumination in the corrected imagery which could be an important factor in the better separation of end members of image and accurate recognition of minerals or alterations.