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Space segment:br /
- 24 satellites on 6 different orbits
- angle of inclination 55°#
- per orbit 4 satellites
- flight altitude 20200 km
control segment:
- 5 worldwide spread earth stations for controlling und observing
- Master Control Station in USA
How does GPS work?
At present 31 active satellites are available, but on earth we are capable to receive 6 to 12 of them simultaneously.
The measuring of an precise position takes place through distance measures of several satellites on known orbits. The terms of these radio signals is countable through these distance measures. To get the precise time the satellites transmit the exact time to the receiver.
3 distance measures are sufficient to get the current position.
Method of distance measuring - one way measures
We are able to measure the position, the moving direction, the speed and the altitude.
The following information will be calculated by the GPS receiver:
distance and direction to the next waypoint, changes of courses, expected arrival, maximum speed, average speed and many more.
At least 4 satellites are needed for a three-dimensional measuring of position (longitude, latitude and altitude)
3 satellites to measure the current position with the x-axis, y-axis and z-axis and one satellite for the time.
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