Chapter 5 Landing Systems Based on Satellite Navigation Systems Global satellite navigation systems (GNSS) are the relatively new generation of radio navigation means. The differences from the traditional radio navigation means which are introduced in Chaps. 2–4 are the globality of operating area, higher accuracy, and possibility of 4D navigation tasks’ solving. Modern satellite navigation systems are GPS (USA), GLONASS (Russia), Galileo (EU), and BeiDou (China). GPS and GLONASS systems came into use in the civil aviation in the mid-end of 1990s. These systems showed their high efficiency quite quickly which led to the real revolution in the aeronautical radio navigation. New technologies of organi- zation and air traffic management appeared and are currently evolving in the basis of GNSS as well as the technologies which provide more effective and safe usage of airspace in conditions of continuous intensity and density growth of air traffic. These technologies are reflected in the Global Air Navigation Plan (GANP) ICAO (Doc. 9750) which determines the development of global civil aviation for midterm perspective as well as in other regulatory documents of ICAO. Unfortunately, even GNSS cannot be ideal, and they are subject to the factors that lower their efficiency. That is why new methods and functional augmentations of GNSS that allow to compensate the impact of destabilizing factors are being developed and implemented. In accordance with the long-term forecasts, GNSS should become main and sus- tainable mean of aircraft’s navigation on all stages of flight including approach and landing itself. That is why this chapter lays emphasis on the methods and perspec- tives of satellite navigation systems’ usage for landing together with overview of main principles of its construction and functioning. Section 5.1 gives common information on satellite navigation systems: Short history of development, structure and the functioning principle, and parameters of existing systems’ orbit groups are analyzed. Content and differences of ephemerides information of GPS and GLONASS systems are analyzed. GPS and GLONASS signals’ structure is overviewed, and comparison analysis of these systems’ signals parameters is performed. With the help of mathematical description, principles and process of solving the navigation task are described. © Springer Nature Singapore Pte Ltd. 2019 O. N. Skrypnik, Radio Navigation Systems for Airports and Airways, Springer Aerospace Technology, https://doi.org/10.1007/978-981-13-7201-8_5 167