Identification of altered minerals in the Yingshan area of Aksu City, Xinjiang, based on the GF-5 hyperspectral data

The GF-5 satellite has obtained nationwide hyperspectral images, which will play a dominant role in its widespread geological application. The GF-5 hyperspectral data is featured by integrated images and spectra, and can simultaneously obtain both the location and types of surface altered minerals. This work identified altered minerals and conducted geological application based on GF-5 hyperspectral data in the Yingshan area of Aksu City, Xinjiang. Through radiometric calibration and atmospheric correction of the hyperspectral data, the image reference endmember spectra were acquired. An improved spectral angle mapping method was employed to map altered minerals, and three types of altered minerals limonite, calcite, and dolomite were extracted. Based on previous geological data, this work analyzed the distribution of altered minerals, and determined the relationship between altered minerals and formation lithology. As a result, inaccurate geological boundaries were discovered in previous geological maps. It is inferred that the GF-5 hyperspectral data can effectively extract altered minerals, and is of great significance in stratigraphic division, lithology boundary delineation, and non-metallic mineral resource prediction.