提取黔西南红粘土的ASTER波段比值技术研究

Research on ASTER Band Ratio to Extract Red Clay in Southwest Guizhou

红粘土型金矿是黔西南的一个重要的金矿类型,我们以往的研究实践表明:Aleks Kalinowski等[1]研制的红粘土型金矿ASTER波段比值4/5不适合黔西南红粘土的信息提取,因此,需要研究适合该地区的ASTER波段比值。ASTER波段比值组合2/1、4/3和(5+7)/6彩色合成后被成功地应用到研究区的红粘土提取中。比值的选择是建立在对矿区红粘土光谱曲线特征的分析和ASTER图像预处理的基础上,该比值组合能够有效提取出ASTER图像上的矿区红粘土信息,并可以扩展应用到周边地区,寻找到更多含金红粘土的分布区,这充分显示了ASTER波段比值彩色合成技术在红粘土提取中的作用。

Red clay-type gold deposit is an important gold type in southwest Guizhou.Our research in the past showed that the ASTER index of band ratio 4/5 put forward by Aleks Kalinowski[1] can not be used for extraction of red clay in southwest Guizhou,so that,a study of ASTER index for red clay extraction in this area is necessary.The combination of ASTER band-ratio images 2/1,4/3 and（5＋7）/6 in RGB were applied successfully for the red clay extraction in study area.The selection of band ratio was based on the analysis of spectra characteristics of red clay samples and preprocessing ASTER image.This combination of band ratios has successfully extracted red clay in the gold mining area,and can assist to find more similar red clay in surrounding area,which demonstrated usefulness of ASTER band ratios color combination in extracting red clay.