Determination of Alterasion Zones Using Hyperspectral Imagery Based on Spectral Unmixing

The remote sensing as new technology provides data from earth with lowest cost and time. The Central Iranian Volcanic Belt is a volcano-plutonic complex which contains extrusive and intrusive rocks of Eocene to Quaternary age. In this area, the Meyduk porphyry copper deposit (55° 10′ 05″ E, 30° 25′ 10″ N) is located 45 km northeast of Shahr-e Babak city. The Cu-mineralization and associated hydrothermal alteration zones are focused on the Miocene dioritic Meyduk porphyry and Eocene andesitic rocks.

Today, remote sensing with having high spatial and spectral resolution, wide coverage and the lowest cost plays a key role in the field of earth sciences research (especially in the mineral ore explorations) (Melesse et al., 2007). In this case, hyperspectral images have a special status in remote sensing. Even though these images have a high spectral resolution, they have not a high spatial resolution. Because of the presence of different prospectives on a ground pixel, the amount of received energy by the receiver is the combination of multiple ground effects. Therefore, low spatial resolution of hyperspectral images can be a reason for spectral mixing in these images (Iordache et al., 2011). The purpose of spectral separation is recognition of observed surface components and calculation of abundance of the inside component of each pixel area. The purpose of applying unmixing algorithm is estimation and extraction of presence percentage of any considered mineral ores in each pixel of the image. We applied mentioned algorithm in three steps. In the first step, estimation of a number of the mineral ore types using Hysime algorithm is done. In the next step, we extracted spectral signature of each of these mineral ores using N-finder and in the final step, we calculated vector abundance of them using FLS algorithm.To evolution performance proposed methods a real hyperspectral were used in this research. The hyperspectral dataset related to Hyperion sensors related to Meyduk that lacoated in Iran. The Hyperion sensors carried by EO-1 satellite that it is first spaceborne hyperspectral instrument to acquire data in a wide of spectral bands.