ANALISIS METODE PENINGKATAN RESOLUSI CITRA OPTIS TERVERIFIKASI LAPANGAN UNTUK MENDETEKSI SEBARAN MINERAL OKSIDA TAMBANG KOLAKA, SULAWESI TENGGARA

• Main Author: Wijdani Sakina, Bella
• Format: Theses
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/86996
• Institution: Institut Teknologi Bandung

One of the commonly used early exploration methods is remote sensing, which can be utilized to support the identification of mineral occurrences. The application of remote sensing technology for mineral identification can be improved using image sharpening termed as pan-sharpening methods to enhance spatial resolution, thus producing more accurate results. This study was focused on evaluating the application of Gram Schmidt pan-sharpening method to identify mineral distribution in the Kolaka area, Southeast Sulawesi Province, with validation conducted in the Northern Mine Prospect area, IUP OP Nickel Commodity UBPN Kolaka, PT Antam Tbk, Pomalaa District. The Gram-Schmidt pan-sharpening method improved the multispectral image with a spatial resolution of 30 m by incorporating the panchromatic image to a new multispectral image with 15 meter spatial resolution. The study involved 186 drill core samples collected from five borehole points to verify the accuracy of the image before and after sharpening. The spectrometric analysis using the ASD TerraSpec Explorer/4 Hi-Res was conducted to identify mineral types based on their reflectance. Geochemical analysis using the X-Ray Fluorescence (XRF) method was also used to evaluate the effectiveness of the Gram-Schmidt method based on the percentage of Ni content in core samples. Correlation results showed that the minerals saponite and antigorite had the highest consistency with increased nickel content. Spectral data from these minerals were then used as references for identifying mineral distribution using the Spectral Angle Mapper (SAM) method. Validation of mineral identification results using a Ni isograde map showed that the distribution of saponite corresponded to Ni content of 1–1.5%, while antigorite was associated with Ni content of less than 1%. In sharpened imagery, the presence of Ni was more consistent with field data, particularly in open-pit mining and residential areas. Spectral validation showed that sharpened image exhibited absorption patterns consistent with core rock sample spectra and reference spectra. In addition, lithological and lineament validation showed that Ni distribution was concentrated in ultramafic rocks with a lineament trend of N 330?E. The accuracy of saponite mineral distribution increased from 50% in unsharpened imagery to 65% after Gram-Schmidt pan-sharpening method.