GPS Satellite Constellation

At a time) are 24 operational satellites in the constellation of GPS satellites orbiting the earth with a radius distance of approximately 16,000 miles (from the center of the earth. The orbits of the satellites are in six orbits (- plan is almost circular orbit is surface through the orbit of satellites being tracked format) are organized. The six orbits separated by an angle of 60 degrees. Four to six satellites occupy each orbital plane.

InIn addition to the 24 operational satellites in orbit currently are 6 satellites, which are kept as spare parts, if a failure of 24 operational satellites. The six satellites are kept operational reserve to receive the user to benefit from them as of 24 satellites. However, the U.S. government does not guarantee their availability at any time.

Remember that the GPS satellites were launched in 1974. Satellites like the rest there is a limitLife. GPS satellites are designed to offer a year of life ~ 8 new satellites are launched into space at regular intervals to compensate for satellites that have lived their lives.

When satellites are launched into space, they have used previously calculated positions in their orbits. The pre-calculations find that a GPS receiver anywhere on earth, and all four signals can be at leastSatellites. This is necessary because the Earth blocks the GPS signals from passing through. For a GPS receiver to be able to receive a signal from a satellite, the line of sight-line would be no interference in between. Since the satellites are flying around the earth, not all satellites are visible, a GPS receiver is located somewhere on Earth. But now there are 30 operational satellites, not everyone can see them in one place on Earth, at anygiven time.

For a thorough knowledge of GPS today, refer to sites like http://www.gadgetknowledge.com/gps1.html

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