Spectral Angle Mapping Using Field Spectra (Case Study: Firouzabad Salt Domes, Fars)

The basic purpose of remote sensing technology is to identify and separate natural phenomena on earth. Classification of satellite images is the most important step in interpreting satellite data. To further investigate advanced spectral processing and image classification techniques, it is necessary to have remote sensing images taken with multispectral bands and with small bandwidth (often in nanometers). The spectrum can then be compared with the spectra of known pure materials such as minerals, vegetation and etc. which are similar to this spectrum can be distinguished. In this study, ASTER sensor data were used. The ASTER sensor, due to its more number of bands than older multispectral sensors, has a greater capability to perform spectral processing and can perform advanced spectral processing that is specifically to the processing of hyperspectral data. Spectral angle mapping (SAM) processing was performed to enhance the lithological and mineralogical units of the Firouzabad salt domes, Fars (Konarsiah & Jahani) using field spectra. Whereas the mineralogical and lithological composition of the salt domes is essentially a mixture of gypsum, anhydrite, halite, lime, shale, clay and marl; two samples, which showed relative purity spectrally, were used for the SAM processing. Enhancements of lime and gypseous units are the result of the process in studied salt domes. The results were compared with geological map, field observations and the accuracy of processing was evaluated.