Remote sensing abnormal extraction of hydroxyl alteration based on PCA method

Abstract Anomalous geological events often occur during the formation and evolution of mineral deposits. The use of remote sensing technology to extract anomalies is one of the important contents of remote sensing prospecting. The principle is to use different minerals to show differences in the responses of different bands of remote sensing images. Landsat satellite has accumulated massive amounts of remote sensing image data since its launch, providing a research foundation for geological remote sensing. This paper takes the eastern part of Tuoli County, Tacheng District, Xinjiang Uygur Autonomous Region as the research area, and selects ENVI software for remote sensing image preprocessing and remote sensing anomaly extraction. Four bands including TM1, TM4, TM5, and TM7 of Landsat5 TM image are used as the basic bands for extracting hydroxyl remote sensing anomaly information. After preprocessing, the influence of vegetation and water bodies on remote sensing prospecting is suppressed by masking method, and then the Corsta method is used to delimit the threshold value to judge the degree of alteration. The PCA method is generally used to extract the remote sensing anomalies of hydroxyl alteration in the study area, and finally the thematic map visually displays the results of the remote sensing anomaly extraction, which proves that the PCA method based on Landsat5 TM images can provide a certain reference for geological work such as prospecting.