- #1
doaaron
- 65
- 4
Hi all,as I understand it, GPS satellites are offset prior to launch in order to correct for the time dilation that they experience in orbit. I am very confused about how this works in practice. I think the velocity of a GPS satellite wrt a position on Earth would depend on the position on Earth where the GPS data is to be analyzed.
I understand that all GPS satellites have the same orbital inclination, so wrt a fixed position on earth, the average velocity over time of the GPS satellites is the same for all of the satellites. So I can safely ignore the effect of the orbit on the amount of time dilation.
But what about the position on Earth? For example, the velocity of an observer at the north pole is very different from the velocity of an observer at the equator. I believe that the relative velocities of GPS satellites wrt the two positions would also be different. So how would this affect the accuracy of GPS?thanks,
Aaron
I understand that all GPS satellites have the same orbital inclination, so wrt a fixed position on earth, the average velocity over time of the GPS satellites is the same for all of the satellites. So I can safely ignore the effect of the orbit on the amount of time dilation.
But what about the position on Earth? For example, the velocity of an observer at the north pole is very different from the velocity of an observer at the equator. I believe that the relative velocities of GPS satellites wrt the two positions would also be different. So how would this affect the accuracy of GPS?thanks,
Aaron