Extract Mineralized Alteration Anomaly Information From ETM+ Remote Sensing Data

In the history of geology, especially in the Paleozoic era,west tianshan which is located the boundry of Siberia, tarim and Kazakhstan-junggar blocks,was the region that Tectono-magmatic activities extremely active. It arcs and generally spread eastwards,and looks like a acute triangle facing east. It is one of world-class orogenic belts. The geologists who work at west tianshan have many great difficulties because of the west tianshan's huge area, bad natural conditions, sparsely populated, low temperature, lack of water, sandstorm and so on.So if we use conventional geological working methods to do mineral exploration, this is not only high cost and low efficiency. Apparently it already cannot satisfy our needs for reforming.With the development of the computer,remote sensing and geographical information system,the manual interpretation,the extraction of mineralized alteration anomaly information and multi-data fusion gained a new breakthrough. This paper based on understanding and absorption of the geological data,select the appropriate method to enhance alteration information of ETM+ image,extract remote sensing alteration anomaly information.The paper researched mainly in the following aspects:(1)During the research I did some preprocessing works on the image I used, such as geometric correction, cutting the image and so on. And then, the image would be done the features and statistical analysis according to the features of ETM+ remote sensing data, next is choosing the best band combination of color synthesis.(2) Using remote sensing software to enhance the image, then to interpret the remote sensing image after enhancement and extract linear struckures, and summarizes the basic structural framework.(3)On the basis of the full analysis of rock mineral spectrum characteristic and the ETM+band performance,use the principal component analysis,supplemented by band ratio,image mask technology to remove vegetation interference information and extract mineralized alteration anomaly information.(4) After making different degree of information on the superposition analysis with the geological data I already have, and doing some studies on comprehensive metallogenic prediction of survey region, then four forecast areas were delineated.