Doppler Processing for Satellite Navigation

Doppler processing was the principle of operation for the first satellite navigation system, Transit, that became operational in 1964 and was phased-out in 1996 [1]. Its successor, the Global Positioning System (GPS) uses the principle of one-way ranging, which requires fewer satellites for a position solution compared to Doppler processing [2]. In recent years, Doppler processing has been revisited for several applications, including precise velocity [3]; positioning with low earth orbit (LEO) satellites using carrier Doppler shift only [4]; combining signal-of-opportunity Doppler measurements from multiple LEO satellite constellations [5]; and solutions combining both pseudorange and Doppler measurements [6]. This paper summarizes different Doppler processing techniques, performance as a function of geometry and error sources, and provides results for several examples ranging from computer models to actual observations from static and dynamic users.