In recent years, the use of Doppler shift measurement for the determination of a user's position, velocity and time is becoming of great interest for the new LEO and MEO constellations as an evolution of the trilateration techniques used in global navigation satellite systems. The concept of using Doppler measurements is not new: it was the basis of the first navigation system, Transit, which operated from 1964 to 1969 before being succeeded by the GPS system. Given the technological evolution and new scenarios embedding large number of LEO satellites an interest in revisiting the Doppler ranging and position concept using modern processing solution has arisen.