Comparison of ASTER and Landsat-8 OLI data for detecting iron occurrences and alteration in Shahrak area, Kurdistan Province

The performance of various spectral processing techniques has been studied and evaluated using the ASTER and OLI satellite images of the Shahrak mining district. The district is located 60 kilometers north of Bijar city, Kurdistan province. Different band ratios and false color composites were prepared to determine which of them are more adequate for the detection of iron occurrences, chlorite-epidote and clay alteration. Principal Component Analysis (PCA), Independent Component Analysis (ICA) and Minimum Noise Fraction (MNF) transforms were also applied to the bands of ASTER and OLI images. The extracted images indicate the OLI image in the PCA method is better than the ASTER image, and is able to detect iron mineralization and clay alteration more efficiently. In the ICA technique, the OLI image also reveals more details, so that the color combination IC3, IC2, IC1, in addition to identifying the above phenomena, also has a high potential for lithological mapping. In the MNF transform, the OLI image performs better than the Aster image. From the three transforms applied, ICA and then MNF had better outcomes than the PCA in the OLI image.