| | Global Positioning System articles and news from Start Learning Now (Site not responding. Last check: 2007-08-13) |
 | | This uses a series of ground reference stations to calculate GPS correction messages, which are uploaded to a series of additional satellites in geosynchronous orbit for transmission to GPS receivers, including information on ionosphereionospheric delays, individual satellite clock drift, and suchlike. |
 | | Low cost GPS receivers (price 0 to 0) are widely available, often combined in a bundle with a Personal digital assistantPDA, car computer, or Vehicle tracking system. |
 | | Many synchronization systems use GPS as a source of accurate time, hence one of the most common applications of this use is that of GPS as a reference clock for time code generators or Network Time ProtocolNTP clocks. |
| www.startlearningnow.com /GPS.htm (5043 words) |