Extracting lithologic information from ASTER multispectral thermal infrared data in the eastern Kunlun

摘要

In this paper, mechanisms of mineral radiation transfer, atmospheric correction and surface temperature retrieve, method of minerals identification based on emissivity spectral features are studied. Mineral radiation transfer can model the mechanisms of spectral formation and variation, and is one of study methods of spectral mechanism. Along with the variation of mineral granularity, the shape and absorption depth of mineral emissivity spectral will all variate. However, the law of emissivity variation with emission angle of different minerals is identical. Along with the increasement of emission angle, emissivity decrease. The more emissivity is small, the more variation range and speed are large. The reflectance mixture of mineral is non-linear, and can be lineated using mineral radiative transfer model. After the mixture spectral is lineated, the precision of linear unmixing of spectral and mineral content extraction will be improved greatly. The atmospheric correction and surface temperature retrieve of thermal remote sensing data will affect extraction lithologic information greatly. In this paper, using the MODTRAN model to atmospheric correction, and using split-window algorithm for retrieving surface temperature from ASTER thermal infrared data. With the minerals emissivity spectral features and the index (QI, CI and SI), retrieving Si0_2 content of rock quantitatively using ASTER thermal infrared data. The method can be used to extract lithologic information.