Application Of Alteration Abstraction Based On Multi-source Remote Sensing Imagery

Utilizing remote sensing technology with multiple source to explore mineral resources,which extract alteration anomaly, can detect mineral information directly and locate possible exploration target area. It is a non-invasive technology among the technologies for mineral exploration. The study area is located in west area of Langshan, Inner Mongolia. Little plant cover and bare pedestal rock make it an excellent application demonstration spot for remote sensing exploration. The research can be divided into two parts by acquiring both multi-spectral data ETM and hyper-spectral imagery Hyperion, but extracting alteration anomaly respectively. First of all, analysis has been carried out on regional geology setting and categories of possible alteration minerals have been determined. In this paper, by use of the principal component analysis method, hydroxyl alteration information is extracted from ETM remotely sensed data on which mask processing (cloud and water mask using band ratio method, alluvium mask though spectral angle mapping method and vegetation mask by band ratios with dynamic threshold method) is used before extraction in the desertification area. After extraction, the standard deviationσwas used as the measure for anomaly slicing. At last, anomaly distribution map is produced.Secondly, based on the theory of wall rock alteration, study and experiment have been carried out on mineralization alteration extracting with hyper-spectral remote sensing imagery. Specifically, research is started with finding some indicating symbols based on alteration theory and studying spectrum features. Further more, preprocess EO-1 Hyperion imagery including remove band lines, de-strip, atmospheric correction and spectral reconstruction. Seven end members have been extracted from inversion reflectance, five of which is used to mapping the study area using SAM method. Thus, five alteration anomalies have been extracted. Besides, overlay analysis of hydroxyl anomaly information extracted from multi-spectral remote sensing imagery with alteration minerals distilled from hyper-spectral data in order to verify the correctness and feasibility of extraction, At last, repeatable technology processes of extraction for mineralization alteration using multi-source remotely sensed imagery have been established.Finally, according to geological setting and previous research about ore deposit especially on ore bearing stratum, forecast other favorable target area using alteration distribution map. The result reveals that extraction of anomalies agree with the ore-bearing strata, formation as well as ore deposit, which shows practical meanings.