Geographic information is composed of all human activities on the surface of the Earth. The Geographic Information Systems (GIS) help us understand the interactions between these activities.
They are increasingly present in our daily lifes, whether for land management (urban and environment activities), navigation systems (car and flight navigation) or for network management (sanitation , energy, waste ,...).
They provide 6 following functions:
The geographic database is imported from files or entered by an operator.
Data processing is done using software on a computer.
A client-server infrastructure (intranet, extranet or the Internet) increase the dissemination of results.
A GIS uses technical knowledge and various skills and trades so that may be made by one or more persons. GIS specialist must mobilize expertise in geodesy (knowledge of concepts of earth datum and projection system), data analysis, process in modeling and statistical analysis, in cartographic semiology.
Like all users of geographic information systems are not necessarily specialists, a Geographical Information System provides a series of toolkits.
The analysis of data and advanced operations are generally assigned to an engineer with good knowledge of data manipulation and the nature of treatments performed by software that allows one to interpret properly the quality of results. The expert on a topic studied occurs sometimes in the technical aspects.