NLES: Radio frequency systems

The project is responsible for the design of the system for the radio frequency components of the Navigation Land Earth Stations (NLES), which are part of the EGNOS system (European Geostationary Navigation Overlay Service), developed by the European Space Agency (ESA), the European Commission and Eurocontrol. These stations transmit correction and integrity messages to EGNOS geostationary satellites, which are ultimately responsible for radioing the SBAS signal to users. These signals allow to obtain a greater precision of the estimation of the position of the users by applying the corrections of the measurement errors of the signal. EGNOS bases its activity on geostationary satellites and ground stations that constantly provide information on errors in GPS signals, providing improvements to the performance of this navigation system. In this sense, the radio frequency components in the NLES are responsible for generating, modulating and adapting the frequency of signals to be correctly received by users. The term radiofrequency refers to frequencies that are present within the electromagnetic spectrum and that are used in radio communications, located between 3 hertz (Hz) and 300 gigahertz (GHz). These frequencies are useful for a wide variety of applications such as military, satellite navigation, radars, radio, among others.