PRISMA hyperspectral imagery for mapping alteration zones associated with Kuhpanj porphyry copper deposit, Southern Iran

Abstract

Hyperspectral images have been extensively employed to map alterations related to various ore deposits, particularly those associated with porphyry copper deposits. The present study aims to evaluate the efficiency of the PRISMA (Precursore Iper Spettraledella Missione Applicativa) satellite imagery, that is an Italian satellite, in identifying and discriminating alteration zones (Phyllic, Argillic, Propylitic) related to a well-known porphyry copper mineralization system in Iran. The chosen algorithms for performance evaluations involve selective principle component analysis (SPCA), spectral band ratios, mixture-tuned matched filtering (MTMF), and linear spectral unmixing (LSU). In this study, new band ratios are also proposed to improve the efficiency of alteration mapping. The results are validated by field data and geological-alteration map demonstrating the overall accuracy of detecting different alteration zones including the Phyllic, Argillic, and Propylitic zones equal to 71.87%, 87.50%, 81.25% and 71.87%, and kappa coefficients of 58.85%, 80.54%, 70.55% and 57.52% for SPCA, band ratio, MTMF, and LSU algorithms, respectively. In current research, it is found that using PRISMA data, the band ratio algorithm is superior when compared to other implemented algorithms in detecting hydrothermal alteration associated with porphyry copper deposits.

Keywords

• PRISMA
• alteration mapping
• band ratio
• SPCA
• MTMF
• LSU