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Early satellite‐based navigation systems c. 1960–1970, such as TRANSIT, utilized a low Earth orbit (LEO) to obtain sufficient Doppler on the carrier phase for positioning. In 1973, satellite navigation in the form of the global position system (GPS) took hold with the formulation of the GPS Program Office, which helps consolidate knowledge from the TRANSIT program, the Navy's Timation Satellites, and the USAF Project 621B satellite pseudoranging program.

Today, GNSSs use medium Earth orbit (MEO) for good visibility/availably of the satellite and still provide moderate Doppler for PVT determination. Some GNSSs also supplement the GNSS constellation with geostationary (GEO), geosynchronous, or inclined geosynchronous (IGSO). These GEO and/or IGSO satellites may provide additional ranging and a data link augmentation for the GNSS constellation.

The various governing bodies for satellite navigation publish technical interface control documents and specification on their respective GNSS. For GPS, the US Government publishes various Interface Specifications and performance specifications at GPS.gov [Ref. [2] in Chapter 4]. For the Russian GLONASS, a multitude of performance and system characterizations are published by the Russian Information and Analysis Center for Positioning, Navigation and Timing. For the European Galileo GNSS, these types of documents are published by the European Global Navigation Satellite Systems Agency [Ref. [26] in Chapter 4]. For the Chinese BeiDou Navigation Satellite System, information and official documents are published (Ref. [27] in Chapter 4). Other regional type satellite navigation systems cover a specific region of Globe such as the Japanese Quazi‐Satellite System (QZSS) (Ref. [29] in Chapter 4) and the Indian Regional Navigation Satellite System (IRNSS): NAVIC (Ref. [30] in Chapter 4) provide service and/or augmentation to a specific geographical region of the Globe.