So I understand the basics of the general and special relativistic effects on the speed of the satellite clocks onboard the GPS satellites, and why they are rigged to calculate time slower than an atomic clock at sea level. But then, in several articles, I read that GPS receivers are also designed to make relativistic calculations as well. What all do the receivers have to compensate for? Just the relativistic doppler effect? None of the articles I came across actually specify anything, let alone everything, the receivers have to calculate relativistically. Any enlightenment would be much appreciated.