The bachelor thesis investigates the structure of GPS signals within the broader context of the satellite navigation. The introduction defines basic concepts and prerequisites for satellite navigation, including a common geospatial and temporal system, and the constant speed of navigation signal propagation. It further, thesis analyses the fundamental services of satellite navigation and various GNSS systems such as GPS, GLONASS, Galileo, and BeiDou, as well as the regional systems. The segments of satellite navigation systems are examined in detail. The main part of the thesis focuses on GPS navigation signals, including signal structure, carrier wave, coded signals and navigation messages. It also addresses the principle of satellite positioning and the overall estimation of the positioning error with underline on the user error distribution. Finally, the thesis discusses the applications of GNSS systems in various transportation sectors and other fields. The conclusions summarize the key opinions and considerations.