This post delves into the inner workings of GPS, breaking down how it calculates user positions. It explains the importance of coordinate systems, such as ECEF and WGS 1984, in expressing positions accurately. The content then delves into the triangulation process used by GPS to determine user positions based on satellite distances. It discusses the intricacies of satellite orbits, clock biases, and atmospheric factors that affect accuracy. Surprisingly, GPS information can be denied due to geopolitical concerns, leading countries like Russia, China, and the European Union to develop their own systems. This detailed breakdown aims to provide a comprehensive understanding of GPS operations.
https://www.telesens.co/2017/07/17/calculating-position-from-raw-gps-data/