Abstract:

Aiming at the problem of remote sensing alteration information extraction in semi-exposed area, this paper proposes a method based on partition processing to extract alteration information. Using Aster image as the main data source, the study area is divided into vegetation area and exposed area by using the normalized vegetation index (NDVI). The exposed area extracts alteration information by using the combining method of lossless linear stretching, principal component analysis(PCA) , abnormal cutting and abnormal filtering. The vegetation area extracts alteration information by using the combining method of vegetation suppression, lossless linear stretching, principal component analysis, abnormal cutting and abnormal filtering. The extracted information is analyzed and verified by using the known geological and mineral data. The results show that the alteration information extracted by this method is in good agreement with the known gold deposits. Based on remote sensing and other information, the remote sensing target areas are optimized, and the target areas are verified in the field. Four mineralized areas are discovered. In summary, this method is feasible for the alteration information extraction in this area, and has important guiding significance for gold exploration.

Key words: semi-exposed area, extraction of alteration information, principal component analysis, vegetation suppression, gold deposit