基于Aster和Landsat8数据在青海赛什腾地区蚀变信息提取研究

青海赛什腾地区位于无人区,穿越条件极差,传统地质找矿勘探工作难以开展,因其植被稀少,有利于多光谱遥感数据提取矿化蚀变信息.本文以Landsat8和Aster数据为数据源,利用成像光谱法和主成分分析法对赛什腾地区进行矿化蚀变信息的提取,成像光谱法包括最小噪声变换(MNF),像元纯净指数(PPI),n维可视化端元识别(n-...

Research on alteration information extraction in Saishiteng area of Qinghai based on Aster and Landsat8 data

Objective:The Saishiteng area in Qinghai province is located in a depopulated zone with poor environment,which can be difficult to carry out geological prospecting through traditional methods.However,multi-spectral remote sensing data provide the great potential for extracting mineralization alteration information in such areas owing to abundant spectrum and continuous space information.This paper extracts remote sensing alteration anomaly information of Saishiteng mining area using Aster and Landsat8.Methods:Some minerals in the study area were identified from Aster data using imaging spectroscopy techniques such as minimum noise transform(MNF),pixel purity index(PPI),n-dimensional endmember recognition visualization(n-dimensional visualization)and spectral angle matching(SAM).For mineralization alteration information,principal component analysis(PCA)was used.Specifically,the band 1,2,3 and 4 of Aster data are used to extract the ferric contamination anomaly alteration,band3,4,6 and 7 were selected to extract the anomaly information of Al—OH altered minerals,and band 1,3,4 and 8 were used to extract the anomaly information of Mg—OH altered minerals.Meanwhile,the band 2,4,5 and 6 of Landsat8 were selected to extract ferric contamination anomaly,and band 2.5,6 and 7 were used to extract hydroxyl alteration.Results:The distribution map of mineral information in the study area was obtained through imaging spectroscopy techniques using Aster data.Through principal component analysis of Aster and Landsat8 data,the ferric contamination anomaly alteration minerals such as pyrite and hydroxyl alteration minerals such as sericite were extracted respectively,and then the distribution map of mineralization alteration information in the study area was obtained.Conclusion:Through the spatial superposition analysis of the alteration information extracted from Aster and Landsat8 data,it can not only quantitatively analyze the extraction effects,but also improve the extraction accuracy,and the ferric contamination anomaly alteration and hydroxyl alteration were demonstrated through measured spectrum profiles and microscopic characteristics of the samples,in addition,the alteration information was verified by the mineralization points of field investigation.Therefore,it can be feasible to extract alteration information based on the two remote sensing data,which has the important guiding significance for delineating prospecting targets.