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NAVSTAR GPS Navigation Signal Timing and Ranging Global PositioningSystem - SummaryThe Global Positioning System (GPS) satellite network is operated by the U.S. Air Force to provide highly accurate navigation information to military forces around the world. The network is also being used by a growing number of commercial products. The GPS space segment consists of into six orbital planes, requiring a minimum of four satellites in each, to operate. The idea for a global positioning/navigation system was first proposed in 1940.Source:http://www.spaceandtech.com/spacedata/constellations/navstar-gps_consum.shtmlGLONASS - Global'naya Navigatsionnaya Sputnikovaya SistemaGlobal Navigation Satellite SystemSummaryThe Global Navigation Satellite System (GLONASS) is based on a constellation of active satellites which continuously transmit coded signals in two frequency bands, which can be received by users anywhere on the Earth's surface to identify their position and velocity in real time based on ranging measurements. The system is a counterpart to the United States Global Positioning System (GPS) and both systems share the same principles in the data transmission and positioning methods. GLONASS is managed for the Russian Federation Government by the Russian Space Forces and the system is operated by the Coordination Scientific Information Center (KNITs) of the Ministry of Defense of the Russian Federation.The operational space segment of GLONASS consists of 21 satellites in 3 orbital planes, with 3 on-orbit spares. The three orbital planes are separated 120 degrees, and the satellites within the same orbit plane by 45 degrees. Each satellite operates in circular 19,100 km orbits at an inclination angle of 64.8 degrees and each satellite completes an orbit in approximately 11 hours 15 minutes.Source:http://www.spaceandtech.com/spacedata/constellations/glonass_consum.shtml
Ionosphere scintillations' - have the potential to cause signal delays, navigation errors or in extreme cases several hours of service lockouts at particular locations. Ø inconvenience for ordinary GPS users, it represents a boon for scientists Ø use of dense networks of hundreds of fixed GPS receivers Ø ability to work like a natural amplifier of seismic waves moving across the Earth's surface. Ø hope is that the technique can be improved in future, Ø separate the small total electron content signal from the very large total electron content variations related to the daily variation of the ionosphere.
Maintained by US the developer of NAVSTARGPS(USA) and GLONASS.</li></ul>Image 1<br />
What is Satellite?<br /> A satellite is an object which has been placed into orbit by hu-man endeavour.<br />Image : 2<br />
What is GPS?GPS, which stands for Global Positioning System, is the only system today able to show you your exact position on the Earth anytime, in any weather, anywhere. Image 3<br />
What is GPS?<br />Ø GPS is the fully-functional satellite navigational system..<br />Ø More than 2 dozen(24+5) of Satellites broadcast precise signal to receiver …<br />Ø Receiver determine their location in any weather &anywhere on the earth…<br /> Image 4<br />
The GPS Satellite System.<br /><ul><li> The 24 satellites plus 5 backup satellites that make up the GPS space segment are orbiting the earth about 12,000 miles above us.</li></li></ul><li>The GPS Satellite System.<br /><ul><li>GPS satellites are powered by solar energy. They have backup batteries onboard to keep them running in the event of a solar eclipse, when there's no solar power.
They are constantly moving, making two complete orbits in less than 24 hours </li></li></ul><li>Concept<br />Triangulation<br />Geometric Principle: <br />You can find one location if you know its distance from other, already-known locations.<br />Image 5.<br />