Satellite-based positioning

In satellite-based positioning, the central problem is to determine the values (X, Y, Z) of a receiver of satellite signals, i.e. to determine the position of the receiver with the accuracy and precision required. The degree of accuracy and precision needed depends on the application, as does timeliness, i.e. are the position values required in real time or can they be determined later during post-processing. Finally, some applications, such as navigation, require kinematic approaches, which take into account the fact that the receiver is not stationary, but moving. 

Satellite-based positioning systems are critical tools in geodetic engineering for the maintenance of the ITRF. They also play a key role in mapping and surveying in the field, as well as in a growing number of applications requiring positioning techniques. The setting up a satellite-based positioning system requires the implementation of three hardware segments:

1. the space segment, i.e. the satellites that orbit the Earth and the radio signals that they emit;
2. the control segment, i.e. the ground stations that monitor and maintain the components of the space segment;
3. the user segment, i.e. the users, along with the hardware and software they use for positioning.