View an animated Flash slide show explaining how GPS works. GPS operates because of three interconnected segments: the satellite, ground control, and user segments. This animation focuses on the satellite and user segments, briefly touching upon how the satellite signal is processed to produce positional values in hand-held GPS units. Note that the accuracy claimed for handheld GPS units 100 m is now routinely exceeded. With the turning off of selective availability, today's GPS handheld units usually get accuracies of better than 10 meters. Note that the video loads slowly.
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