# Calculate Accuracy of GPS?

by godtripp
Tags: accuracy
 P: 608 You can pretty much calculate the discrepancy using the following equations and quantities- Time dilation due to gravity (GR)- $$d\tau=dt\sqrt{1-\frac{2M}{r}}$$ where $M=Gm/c^2$ Time dilation due to velocity (SR)- $$d\tau=dt\sqrt{1-\frac{v^2}{c^2}}$$ Quantities required- Earth's mass Earth's (mean) radius satellite's altitude satellite's velocity