GPS

**Global Positioning System**
The Global Positioning System (GPS) was launched and is operated by the United States Department of Defense and is open for civilian use for navigation, recreational, as well as research and educational uses. The GPS is made up of 27 satellites in geosynchronous orbit at an altitude of approximately 12,000 miles above Earth. Twenty-four (24) of these satellites are in operation at any one time with three (3) in reserve.

rss url="http://www.diigo.com/rss/user/Briancsmith/gps" link="true" number="10" date="true"