利用ASTER热红外遥感数据开展岩石化学成分填图的初步研究

ASTER遥感成像仪的发射提供了廉价的多光谱热红外数据,是热红外遥感数据的一个重要来源。ASU热红外光谱库提供了多种矿物的热红外发射率波谱的同时,还提供了矿物的化学成分即氧化物含量的分析结果。把ASU波谱库的矿物波谱重采样至ASTER各热红外波段,对矿物的波谱进行波段比值处理,与各矿物成分进行相关分析,选择波段比值与各氧化物含量最大相关系数,进行对数模拟,从而可以确定出发射率光谱与化学成分的数值关系。本文分别对SiO2,MgO,Al2O3,CaO,K2O,Na2O进行了数值分析及公式模拟。统计是根据各矿物做出的,模拟公式同样适用于岩石,进而可以在遥感热红外数据中得以应用。在四川省西范坪矿区利用模拟公式对SiO2,Na2O,K2O三种氧化物进行了岩石填图,在野外大部分得到了证实;利用SiO2进行了硅化蚀变带填图,在异常带内发现了砂岩型铜矿化。

The Pilot Study on Petrochemistry Components Mapping with ASTER Thermal Infrared Remote Sensing Data

ASTER has thermal infrared bands and provides a potential to lithological mapping on the earth. The ASU thermal spectral library consists of thermal infrared emission spectra of pure minerals, with an emphasis on common rock-forming minerals. Each mineral spectrum is-accompanied by physical and compositional information. The minerals spectra are resampled to ASTER thermal bands, and the band ratios are analyzed with the oxide components correlation coefficients. TO select the maximum correlation coefficient, and create the simulation formula on the emissity spectra ratios and the component, then the relationship between the spectra and the component is established. The SiO2, MgO, Al2O3, CaO, K2O, Na2O components formula are established differently. The statistics was done by the minerals and it can be applied to the rocks and the ASTER imageries. To use the simulation formula in the Xifanpin copper deposit area, and use the SiO2, Na2O, K2O contents to lithology mapping, most areas were validated. By using SiO2 contents to classify the silica zone, sandstone-type copper mineralization was found in the anomaly zone.