عنوان مقاله [English]
The cost of collecting basic information accounts for about seventy five percent of the total cost of geographic information systems.
Satellite images, while significantly reducing the cost of providing geographic information, improve the orderly revision and update of information, and provide satellite imagery with technically advantages such as:
• A comprehensive and consistent view of each area of land;
• Ability to regularly and continuously revise and update geographic information;
• direct transfer of digital satellite imagery to the GIS;
• access to archives of satellite images easily.
Currently, a large part of the Earth's surface measurements are obtained from satellites. This will revise and expand our understanding of different conditions of the earth. Remote-exploration satellites provide an opportunity for continuous multi-time measurements from a wide area during a particular period of time. For this purpose, satellite data should be in a suitable format and in a manner consistent with other ground information in the GIS.