Thermal anomalies can be determined by using remote sensing satellite images as Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER). For doing that, variety of algorithms and methodologies is used by taking into account physical phenomena. Thermal infrared energy which is emitted from different objects such as vegetation, soil, water, rocks, minerals is sensed by reflective infrared (0.7-3.0 μm) or thermal infrared regions using different sensors. These regions are mentioned as Short Wave Infrared (SWIR) and Thermal Infrared (TIR) portion of electromagnetic spectrum, respectively. The remote sensing satellite system boarded with TIR sensors sense radiant temperature of an object which is correlated with its true kinetic temperature. Atmospheric water vapor and other gases should be taken into account as it decreases thermal infrared energy reaching to TIR sensors. So, the pixel size of the thermal infrared sensor is high (e.g., 90m pixel size for ASTER) in order to compensate low radiation of thermal energy.

In this study, Visible/Near Infrared (VNIR), Short Wave Infrared (SWIR) and Thermal Infrared (TIR) data was studied in Tuzla geothermal region. Tuzla geothermal field is located in the southwest of the Biga Peninsula around the village of Tuzla. The geological units in Tuzla geothermal field occurred volcanic ignimbrites and sedimentary conglomerate-sandstone-mudstone units. The faults and surrounding cracks in the region has increased the mobility of the geothermal fluid, and they have created the hydrothermal alteration.

Principal component analysis was applied to SWIR and TIR bands to reduce the amount of the data resulting in principal components. The principal component analysis was used in order to highlight thermal anomalies. TIR data was also examined for hot springs. Land surface temperatures (LST) were estimated from the satellite imagery of thermal bands using inversion of Planck function.