利用ASTER影像识别和提取矿化蚀变信息

Identification and extraction of mineralized alteration information by ASTER remote sensing data

利用USGS波谱数据库中ASTER影像,对西藏中南部某研究区反射率数据进行蚀变遥感异常提取。整景ASTER遥感蚀变信息提取以光谱角识别法为主,辅以主成分分析法和比值法进行异常的筛选;采用1、2、3、4波段组合,1、3、4、5波段组合,1、3、4、6波段组合和1、3、4、8波段组合,可以分别提取Fe3+、Al-OH基团、CO2-3离子团和Mg-OH基团信息。将提取的蚀变信息成果与已知矿点和区域地质资料对比,结果与实际分布吻合性好。

Extraction of remote sensing alteration anomaly is carried out on the reflectance in central and southern Tibet by ASTER remote sensing data of USGS spectral database. Spectral angle mapping is used as the primary method to extract mineralized alteration information from the whole scene of ASTER remote sensing imagery,and methods of principal component analysis and ratioing are used secondarily to screen anomalies. Several groups of bands( Bands 1,2,3,4,Bands 1,3,4,5,Bands 1,3,4,6,and Bands 1,3,4,8),are employed to extract respectively the information of Fe3 +ionic group,Al- OH group,CO2-3ionic group,and Mg-OH group. The extracted alteration information is compared with known mineral sites and regional geology data, and the results are coincided with the fact.