The Extraction of Altered Mineral Information Based on ASTER Data: A Case Study of the Huangshan Copper-Nickel Ore District in Hami

Abstract

Choosing the Huangshan copper-nickel ore district as the study area and ASTER data as the data source,the authors analyzed the spectral characteristics of the typical features in ASTER bands,designed the process of extraction of alteration information,and discussed in detail "de-interfered anomalous principal component thresholding technique based on spectral angle mapping(SAM)",which was applied to the four groups of common altered minerals containing different ions or groups,and the technique included the extraction of the alteration information by principal component analysis(PCA)and de-interfered anomaly by SAM.The four groups of common altered minerals are as follows:minerals containing Fe ion(goethite and hematite),minerals containing CO2-3 group(calcite and dolomite),minerals containing Al-OH group(muscovite,montmorillonite and kaolinite) and minerals containing Mg-OH group(chlorite and epidote).The results of extraction show that the way of "de-interfered anomalous principal component thresholding technique based on SAM" is feasible and the result is consistent with the reality.It is proved evidently that ASTER data have great capability of depicting minerals in the short wave infrared range.