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GPS Overview
The Global Positioning System (GPS) is a satellite navigation system developed and maintained by the U.S. government. Initially designed for military applications, civilian users have found numerous applications using GPS.
On March 29, 1996, a Presidential Decision Directive (PDD) was signed by President Clinton that described GPS as an international information utility. The PDD included the following directives:
- The U.S. government will continue to operate, maintain and provide basic GPS signals worldwide, free of direct user fees.
- The U.S. will advocate the acceptance of GPS and it's augmentations as a standard for use by initiating international discussions and agreement with Japan and Europe.
How GPS Works
Radio signals are sent from orbiting satellites to earth. GPS receivers on the ground can collect and convert the radio signals into position, velocity, and time information.
Some GPS receivers have the ability to store attribute information in addition to position information. Examples of attribute information are the condition of a street sign, the name of a road, or the condition of a fire hydrant. Position and attribute information can be stored in a Geographic Information System (GIS) to help users manage their assets more efficiently.
For more information see GPS Tutorials.
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