Application Of GPS On GIS Data Collection

The global positioning system (GPS) allows the accurate positioning of an object using satellite signals. There are a lot of applications of this technology in many scientific fields all over the world. It must be mentioned at this point that, on the 1st of May of the year 2000 the selective availability (SA) of GPS that had been into force since 1990 terminated. The SA was a method to reduce the accuracy provided by the system to the civilian users.Geographical information system (GIS) is designed to store, retrieve, manipulate, analyze, and map geographical data. The central element of a GIS is the use of a location referencing system so that data about a specific location can be analyzed in its relationship to other locations. In recent years, the rapid increase in the development of GIS has led to the development of GPS/GIS applications. Therefore, the geometric and geographic information obtained by the use of GPS can be introduced to GIS database and thus thematic maps can be produced. Contrary to the conventional mapping and land-survey tools, GPS increases the precision, speed and distances over which baselines can be measured. Data collection and the ability to post-process the data in geographic information system makes life easier for staff engaged in field surveys.In the framework of this paper, an overview of principle of GPS is presented. Meanwhile, the application of GPS surveying in GIS data acquisition may put forth some questions and problems, to which the solutions are given in the paper. Some problems identified and some results produced are presented and discussed by making experiment and analyzing the data obtained.