利用Aster数据估算Ca含量分布的研究

元素在地表的分布对矿产的赋存具有指示作用，而不同元素都有各自对应的光谱特征；使用光谱数据元素含量可快速、大面积提取元素分布信息，指导找矿工作。本文基于实地测量的岩石光谱发射率数据重采样至ASTER各热红外波段，然后进行波段比值处理；将波段比值与岩石中的Ca进行相关分析。使用SPSS软件做多元逐步回归，排除相关系数小及具有共线性的波段比值，得出Ca与发射率光谱的数值关系；通过数值关系计算，得到Ca含量的大致分布区域。结果表明，Ca含量与ASTER波段之间有较好的相关关系；利用ASTER波段反演地表岩石Ca含量是可行的；在Aster影像上Ca高含量地区与地层的岩性吻合度高。

Study on the Aster data-based estimation of Ca content distribution

Element distribution at the surface of the earth is the indication of the occurrence of mineral deposits. Each element on the surface has its own characteristic spectrum. Inversion of spectral data to element content can be used to abstract information of element distribution in large area and guide ore prospecting. The field measured spectral emissivity data are resampling to the ASTER thermal infrared bands and then the band ratio procession is made. The correlation analysis between the band ratio and the Ca in the rock is carried out. The SPSS software is used for multiple stepwise regression to eliminate band ratio with small correlation coefficient and co-linearity and the correlation coefficients of Ca and emissivity spectrum are obtained. The approximate distribution area of Ca content can be obtained by numerical relation calculation, which can fit well with the actual distribution area of Ca. The results show that there is a good correlation between the content of Ca and the ASTER band, and it is feasible to use the ASTER band to retrieve the Ca content of the surface rock. In the Aster image, the high content area of Ca is in good agreement with the lithology of the formation.