高植被区多源遥感数据蚀变信息提取与分析

发布时间：2018-04-08 21:23

本文选题：蚀变信息　切入点：遥感　出处：《成都理工大学》2017年硕士论文

【摘要】：在进行矿产资源勘查时人们通常利用多源遥感数据提取与矿化有关的蚀变信息,以达到对成矿有利靶区的圈定或预测。在植被覆盖区能否最大程度的降低植被对矿化信息提取的干扰,将会对成矿有利靶区的准确圈定或预测产生巨大的影响。本研究所选择的区域位于贵州省马溪幅与施秉幅,该地区矿产资源相对丰富,但植被覆盖度高,采用遥感对蚀变信息进行提取难度较大。针对这一难题,本研究选择植被覆盖度+掩膜、混合像元分解两种降低植被影响的方法,以ASTER与Hyperion为基础数据源,分别完成该地区矿化蚀变信息提取,并对提取结果进行综合对比分析,以筛选出最适合于研究区蚀变信息提取方法,同时也为其它类似区域遥感蚀变信息提取提供科学参考。本论文主要开展了如下工作:(1)通过数字图像处理方法对ASTER与Hyperion数据进行预处理。笔者采用ENVI软件提供的FLAASH模块对多光谱与高光谱数据进行大气校正,校正后的影像数据不仅能够更加真实的反应地物的反射率信息,而且图像清晰度也得到了提高。(2)使用ASTER多光谱数据对研究区进行铁染与碳酸盐化蚀变信息提取。针对研究区植被覆盖较高的特点,选择植被覆盖度+掩膜、混合像元分解两种方法抑制植被影响,在此基础上用比值法与主成分分析法分别进行蚀变信息提取。经过与已知地质资料叠加分析及野外验证,发现“基于混合像元分解+主成分分析”法不仅能充分抑制植被而突出矿化信息,而且提取结果精度优于其它方法,在空间分布上与地层、断层有着密切的关系。(3)应用Hyperion高光谱数据对高植被区碳酸盐化开展了蚀变信息提取。针对高光谱数据特点,使用高斯径向基核主成分分析方法对其进行降维处理,取得较好效果。在此基础上利用PPI与N维可视化工具提取纯净端元,并与野外实测波谱数据进行匹配分析,最终利用光谱角技术进行矿物填图。经过分析表明高光谱识别的白云石与方解石信息与多光谱提取的碳酸盐化蚀变信息匹配度较好,但高光谱提取的方解石与白云石信息更加的清晰。
[Abstract]:In the process of mineral resources exploration, people usually use multi-source remote sensing data to extract alteration information related to mineralization, in order to delineate or predict the favorable target area for mineralization.Whether the disturbance of vegetation to the extraction of mineralization information can be minimized in the vegetation coverage area will have a great influence on the accurate delineation or prediction of the favorable target areas for mineralization.The region chosen by this study is located in Maxi and Shi Bingzun Guizhou Province. The mineral resources in this area are relatively rich but the vegetation coverage is high. It is difficult to extract alteration information by remote sensing.In order to solve this problem, two methods of vegetation coverage mask and mixed pixel decomposition were selected to reduce the vegetation influence. Based on ASTER and Hyperion, the mineralization alteration information was extracted in this area.In order to select the most suitable method for extracting alteration information in the study area and provide a scientific reference for the extraction of alteration information from remote sensing in other similar regions, the results of extraction are compared and analyzed comprehensively in order to find out the most suitable method for extracting alteration information in the study area.The main work of this thesis is as follows: 1) preprocessing ASTER and Hyperion data by digital image processing method.The atmospheric correction of multispectral and hyperspectral data is carried out by using FLAASH module provided by ENVI software. The corrected image data can not only reflect the reflectivity information of ground objects more truthfully.The image clarity is also improved. (2) ASTER multispectral data is used to extract iron stain and carbonation alteration information from the study area.In view of the characteristics of high vegetation coverage in the study area, two methods of vegetation coverage masking and mixed pixel decomposition were selected to suppress the vegetation influence, and the ratio method and principal component analysis method were used to extract the alteration information respectively.After superposition analysis with known geological data and field verification, it is found that "principal component analysis based on mixed pixel decomposition" can not only fully suppress vegetation and protrude mineralization information, but also has better precision than other methods.The Hyperion hyperspectral data are used to extract the alteration information of carbonization in the hypervegetation area.According to the characteristics of hyperspectral data, Gao Si's radial basis kernel principal component analysis method is used to reduce the dimension, and good results are obtained.On this basis, the pure end elements were extracted by PPI and N-dimensional visualization tools, and matched with the field measured spectral data. Finally, the mineral mapping was carried out by spectral angle technique.The analysis shows that the hyperspectral information of dolomite and calcite is better than that of multi-spectral extraction of carbonation alteration information, but the information of hyperspectral extraction of calcite and dolomite is more clear.
【学位授予单位】：成都理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：P627

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