Using GIS technologies in processing and interpretation of satellite images.

The Geographic Information System is a collection of located, collected, stored and managed geographic data with the use of the computer, data which can be used to perform various spatial analyses. The special GIS operations over the spatial information make from these instruments more than just efficacy instruments for making maps, but especially, irreplaceable instruments for analyzing the information that refer to the terrestrial surfaces. GIS maps must be made exploiting all available resources based on rigorous analysis of their content and the costs involved, seeking assurance required with maximum efficiency. Each data source requires the existence of specialized programs that would bring appropriate map data into digital form, starting with providing necessary equipment, going through technological problems and data conversion, with the purpose of preparation and proper training of personnel. In a GIS, data can be stored in two fundamental spatial data models: vector and raster. Raw raster data can be as follows: satellite images or orthophotos, while the raw vector data can be obtained from topographic survey or data acquired by GPS technology. The information obtained from remote sensing is contained by the cosmic or aerial images, which can be interpreted for many purposes. Building these images is based on detection and registering of electromagnetic energy reflected or issued by the surface of the objects present on the visual field of the sensors, which interacted with the electromagnetic energy issued by a natural source (e.g. Sun, Moon) or an artificial one (e.g. radar). The response of the objects from nature to various wavelengths of electromagnetic radiation is different, depending on their physical and chemical properties, configuration and surface roughness, its illumination intensity and angle of incidence. These responses recorded via sensors translate the image by the emergence of patterns (features), based on which objects can be distinguished and identified. The remote sensing data is public, meaning it can be acquired from any area of the world and by anyone, with some restriction.