Study On Extraction Of Mineralization And Alteration Information Based On Multi - Temporal Remote Sensing Data Fusion

Remote sensing technology has been widely used in various fields in the past years of studies. Extracting alteration information by remote sensing has become one of the important parts in the field of geological exploration research in modern times. However, the information which can reflect the altered rocks of remote sensing is often interfered by other surface features and restricted by spectral resolution and spatial resolution in the process of extracting mineralized alteration information of remote sensing. So the performance of mineralized alteration information that indicated by mineralization is often very weak. It is difficult to enhance alteration information and extracted alteration information by normal methods. In order to extracting alteration information more effectively to enhance expression of the information in the remote sensing images, new technologies and new methods to extract alteration information by remote sensing technology is needed.Based on the above background, this study was focused on using temporal merging of remote sensing data extract alteration information after the combination of extracting alteration information of Huize lead-zinc deposit by using remote sensing technology and temporal merging of remote sensing data according to geological condition. The methods of extraction alteration information by remote sensing image using temporal merging of remote sensing data was studied according to geological data in the study area and the results of exploration in the field. The main research contents and results of the paper are as follows:(1)The concept of temporal merging of remote sensing data was defined. Also the method of temporal merging of remote sensing data was discovered. Temporal merging was a process of merging multitemporal remote sensing data. This process included analyzing, testing, uniting and debugging multitemporal remote sensing data to get the data which united the advantages of remote sensing data from different times. A new set of remote sensing data which was better for subcequent research was obtained after redundant information was deserted or weakened. The method of temporal merging of remote sensing data was a combination of the samples which obtained at each time period. Then the average of the new sample was calculated based on the gotten data to get an average of each sample in each time period.(2)To retain the spectral features of alteration information that were not changed greatly in a short time as many as possible and weaken the importances of vegetation information, water system information and information of human activities to prominent alteration information more favorablely on remote sensing images and extract alteration information more effectively on remote sensing images,14 TM Landsat5 images in 2000-2006 and9 OLILandsat8 images in 2013-2015 were merged by the method of temporal merging respectively.(3). The before and after data were analyzed by comparing remote sensing from subjective and objective aspects after temporal merging. From the visual point of view, color of fusion image was deepened. Vegetation boundaries were more obvious due to the temporal merging years of images Which had leaded to less vegetation information than single image. The point was that the affects of vegetation on the results had reduced in alteration information extraction. Objectively, the results were compared and evaluated by such evaluation indexes:mean, variance, entropy and correlation. According to the results, the temporal merging remote sensing data is better than the original.(4) OLI images and TM images which had merged by temporal merging of remote sensing data were extracted by using principal component analysis, independent principal component analysis and ratio method. Then alteration information of merged images were compared with the single. Results showed that information structure which extracted on TM images and OLI images in each time period data were stronger. It meant that alteration information distributed on TM images and OLI images in each time period data were larger and had more false anomalies. The regions of alteration information which were extracted were more concentrated. Also the false abnormal was inhibited effectively. The results had been proved to be credible. Alteration information which was extracted on TM images and OLI images in temporal merging of remote sensing data showed that the regions of hydroxy abnormal alteration were mainly in the niulan river area and the regions of vegetation covered. The region of exist iron abnormal alteration mainly in northeast of Kuangshan town.