GPS Navigation Satellite One of the first scientific applications of GPS was to precisely determine the position of fixed ground antennas in order to study the dynamics of the Earth surface. It was soon realised that in order to obtain the best results it would be necessary to compute very precise orbits of the GPS satellites. A number of groups started doing this and, as a result, the first orbits that were precisely obtained using GPS were those of the GPS satellites themselves.

GPS Navigation Satellite systems have become so widespread that they are almost taken for granted. However, the fact that they are so useful is leading to an expansion of available systems. Several countries are working on systems so product selection may become more complicated. To start, one must have a solid understanding of how satellite navigation systems work, as well as the terminology that is commonly used when referring to the technology.