Research On Remote Sensing Mineral Information Extraction Based On Fractal Theory

Jiangxi Gannan area,which is one of the nonferrous metal bases in China,located in China's important Nanling Yanmu activity belt.It is representative of the extraction of remote sensing mineralization information here.In this paper,ETM + image and ASTER image are used to extract the linear tectonic information and alteration information of the study area.Fractal theory can reveal the hidden law behind the complex phenomenon through irregular phenomena.Therefore,the fractal method is applied to the quantitative analysis of structural information and the analysis of alteration information in the study area,so as to study the mineralization information of the study area.The main contents and achievements of this paper are as follows:1.Through the analysis of the geological data and image data in the study area,it is found that there is a lot of information in the study area that has an effect on the extraction result,such as vegetation,river,quaternary and mountain shadow,especially vegetation cover.Before the extraction of the mineralization information in the study area,the image was studied by using the "high vegetation area mask + low and medium vegetation area suppression" in the vegetation coverage area,and then treated with other interference information to remove,and achieved a better application effect.2.Quantitative analysis of linear construction information,the dimension statistics are carried out by box counting method,draw a fractal dimension map of linear constructs.3.There are many methods to extract the alteration information.In this paper,a comparative study of the effects and advantages of common ratio method,principal component method,ratio + principal component method and spectral angle method is given.Summed up the situation for the study area of the iron alteration information extraction process.4.In the classification of the alteration information,the thresholds are selected by the threshold method and the fractal method respectively.Through the comparative analysis,the thresholds selected by the least squares fitting in the fractal method have more geological connotations.According to this,the hierarchical map of iron alteration information in the study area is drawn.5.The ETM + image and ASTER image were used to extract the iron alteration information in different ranges,and the extraction effect and application value of the two images were explained by the combination of the geological data.6.The linearly constructed fractal dimension contour map,the iron-stained anomaly grading map and the geological map are superimposed,and it is found that the region with high fractal dimension also contains a large amount of alteration information,and the distribution characteristics are consistent.Out of a certain accuracy of the mineral prediction target area.The feasibility of the method in the study is confirmed by comparison with the known geological data such as mine and mining area.