利用TM数据提取含金蚀变带的方法研究──以冀北东卯地区为例

STUDY ON THE METHOD OF IDENTIFYING HYDROTHERMALLY ALTERED ROCKS USING TM DATA

卫星遥感技术是一种利用电磁波作载体从高空探测地面信息的技术。在遥感地质找矿中，环境因素对成矿条件信息的增强和提取来说可以认为是干扰因素。这种环境干扰因素在空间上可分为集中分布的和分散分布的两类。本文是用图像分割的方法从ＴＭ的７个波段原始数据中去掉集中分布的环境因素，用ＰＣ统计数据的二维散点图所表达的数据特征，把地质目标信息和分散分布的环境干扰因素分开，实现排除二类环境干扰因素，从而增强提取含金蚀变带信息的目的。

Abstract Satellite remote sensing can detect earth.surfacial features from space. The environmental factors impact on TM data spectral signatures used to differentiate the alteration from surrounding rocks, is evaluated in Dong mao area.The method studied includs three aspects(1) TM data mask; (2) PCA, (3)PC component bilinear scatter map (MPS). TM data mask is used to mask out those pixels representing loess and clouds. PCA can increases the seperation between specture features more than one TM bands and then it follows that fewer bands to be used achieve higher degree of accuracy for ident ifying the altered rock spectrum signature. The Pc Component Scattering map is used to Analysis of PC component weighings and then the classification map is made according to the analytical result. This process can be monitored by the interactive mode between geologist and computer.This method is proved to be very effective in the study. The method is also successfully applied in recognating alteration in high altitude area in Northen Canada