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Flashcards in Global Positioning System Deck (6)
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Receivers calculate distances to satellites as a function of the amount of time it takes for satellites to reach the ground D=s*t


GPS Segments

Space Segment
User Segment
Control Segment


Space Segment

Orbits are arranged so that at any time, anywhere on Earth, there are at least four satellites visible in the sky.
27 Solar Satellites, 24 in operation, 3 extra in case of failure
Orbits 12,000 miles


User Segment

Receivers that decode the signals from the satellites
Task: Selecting satellites
acquiring GPS signals
Measuring and tracking
Recovering navigation data


Control Segment

Measures distances to satellite and send to the master control.
Determines: satellites orbits
clock performance
health of satellites
-Send commands and data to the constellation


How GPS Works

Receiver has to know two things: Location of at least three satellites above you
The distance between you and each of these satellites. Satellites transmit two signals on different frequencies(microwaves/radiowaves) that electromegneticly travel at the speed of light(186,000mps)