Much of the delay caused by a signal's
trip through our atmosphere can be predicted.
Mathematical models of the atmosphere take into account the charged particles in the
ionosphere and the varying gaseous content of the troposphere.
On top of that, the satellites constantly transmit updates to the basic ionospheric
A GPS receiver must factor in the angle each signal is taking as it enters the
atmosphere because that angle determines the length of the trip through the perturbing
Hey, THIS IS ROCKET SCIENCE!