عنوان مقاله [English]
In this research, the method of extraction and identification of hot and cold water springs using thermal images of TM and ETM+ is investigated. The process is as follows. After taking images from the TM and + ETM sensors on different dates and implementing geometric and radiometric corrections on the images, surface temperature (LST) for the images is extracted using existing relations. Of course, this requires NDVI and emission extraction for the studied areas due to the certain effect of vegetation on surface temperature.
This was carried out in TM and + ETM images using bands 3 and 4 .
After the extraction of surface temperature by using limits and surface profiles in different directions and by using high pass filters, and finally matching vector layers related to the location of the springs on available images prepared by GPS during the fieldwork, the ability of TM and ETM+ images to identify the springs was evaluated. The results show that the use of images of cooler seasons has a higher priority and importance in comparison with the warmer seasons for the identification and extraction of thermal points and thermal anomalies of the surface of the earth on the images. The reverse is true for the identification of cold springs. Furthermore, the size and temperature of springs regarding their geographical location can be effective factors in identifying and separating these resources.