Rock type classification by multi-band TIR of ASTER

The ASTER TIR (thermal infrared radiometer) sensor has 5 spectral bands over 8 to 12 mum region. Rock type classification using the ASTER TIR nighttime data was performed in the Erta Ale range of the Ethiopian Rift Valley. Erta Ale range is the most important axial volcanic chain of the Afar region. The petrographic diversity of lava erupted in this area is very important, ranging from magnesian transitional basalt to rhyoutes. We tried to classify the rock types based on the spectral behavior of each volcanic rock types in thermal infrared range and estimated SiO2 content with emission data by the ASTER TIR. The associated VNIR and digital terrain model (DTM) derived from the stereo pair in the same data set provided a consistent result with that from TIR.