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Calculate Accuracy of GPS?

  1. Nov 22, 2011 #1
    Hello,

    I need to calculate how accurate a GPS system is using only Special Relativity and a very basic knowledge of GR (without tensors...which is limited).

    I'm not sure where to begin however... where does the uncertainty in the measurement come from? How can I calculate the size of the uncertainty of a GPS position?

    Any references or insight would be GREATLY APPRECIATED.

    Thanks PF,

    J
     
  2. jcsd
  3. Nov 24, 2011 #2

    stevebd1

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    Insights Author
    Gold Member

    You can pretty much calculate the discrepancy using the following equations and quantities-

    Time dilation due to gravity (GR)-

    [tex]d\tau=dt\sqrt{1-\frac{2M}{r}}[/tex]

    where [itex]M=Gm/c^2[/itex]

    Time dilation due to velocity (SR)-

    [tex]d\tau=dt\sqrt{1-\frac{v^2}{c^2}}[/tex]

    Quantities required-
    Earth's mass
    Earth's (mean) radius
    satellite's altitude
    satellite's velocity
     
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