Differentiating rock and mineralogical units of Firouzabad salt domes, Fars, by using band ratioing in thermal ASTER data

Some materials in SWIR+VNIR wavelengths due to reflection processes have similar features and responses; in contrast, they show different characteristics in the thermal band (TIR). Therefore, thermal data may offset the lack of information in other spectral segments. AST_05 data was used to process the ASTER data in the infrared thermal range. AST_05 is the product of surface emission data (ASTER sensor) with 90 m2 resolution that are produced only for the infrared thermal band of this sensor. Band ratioing represent the slope of changes the spectral reflectance curves between the two bands. The main mineralogical units in salt domes include calcite, gypsum, anhydrite, salt and clay (illite). Spectral resampling of these minerals was performed in the infrared thermal range of the ASTER bands and the ratios of 12/13, 11/12, 12/11 and 10/11, respectively were used to enhance and differentiating halite (salt), calcite, gypsum, and clay, in the salt domes of Firouzabad, Fars (Konarsiah & Jahani). The results were compared with geological map, field observations and the accuracy of processing was evaluated.