半裸露区遥感蚀变信息提取研究——以甘肃玛曲地区为例

The Extraction of Alteration Information with Remote Sensing Image of Semi-exposed Area: A Case Study of the Maqu Area in Gansu

针对半裸露地区遥感蚀变信息提取的问题,提出基于分区处理提取蚀变信息的方法。以ASTER影像为主要数据源,利用归一化植被指数(NDVI)将研究区划分为植被区和裸露区,裸露区采取"无损线性拉伸+主成分分析+异常切割+异常滤波",结合植被区"植被抑制法+无损线性拉伸+主成分分析+异常切割+异常滤波"的方法,提取研究区的矿化蚀变信息。结合已知的地质矿产资料,对提取的信息进行了分析验证。验证结果表明,该方法在研究区提取的蚀变异常信息与已知金矿吻合较好。综合遥感等多重信息进行了遥感靶区优选,并对靶区进行了野外查证,发现了4处矿化区域。综上所述,该方法对本地区矿化蚀变信息的提取是可行的,对金矿勘查具有重要的指导意义。

Aiming at the problem of remote sensing alteration information extraction in semi-exposed area,this paper proposes a method based on partition processing to extract alteration information.Using Aster image as the main data source,the study area is divided into vegetation area and exposed area by using the normalized vegetation index(NDVI).The exposed area extracts alteration information by using the combining method of lossless linear stretching,principal component analysis(PCA),abnormal cutting and abnormal filtering.The vegetation area extracts alteration information by using the combining method of vegetation suppression,lossless linear stretching,principal component analysis,abnormal cutting and abnormal filtering.The extracted information is analyzed and verified by using the known geological and mineral data.The results show that the alteration information extracted by this method is in good agreement with the known gold deposits.Based on remote sensing and other information,the remote sensing target areas are optimized,and the target areas are verified in the field.Four mineralized areas are discovered.In summary,this method is feasible for the alteration information extraction in this area,and has important guiding significance for gold exploration.