This thesis introduces total system simulations of global navigation satellite systems (GNSS). GNSS total simulations emulate all components also involved in real-world satellite navigation, i.e. the space segment, the control segment, and the user segment. For this, the outputs of a real GNSS receiver are emulated, providing idealized GNSS measurements without any errors first. Being affected by various sources in reality, such errors also have to be added to the idealized measurements in order to obtain realistic measurements. To this end, various sources of GNSS errors have been modelled and implemented in the existing navigation framework TriPos. Ideally, the resulting GNSS measurements cannot be distinguished from actual measurements output by GNSS receivers. For this, the implemented GNSS total simulation uses the same interfaces as real GNSS receivers, so that each subsequent processing can use inputs from either real or simulated GNSS receivers. This enables the use of GNSS total simulations as a general tool for manifold analyses of different GNSS-based technologies. For demonstrating the use of GNSS total system simulations, the Ground Based Augmentation System (GBAS) was selected. GBAS offers multiple services for precision approaches of aircraft. It is, however, threatened by anomalies in the Earth's ionosphere. Strong gradients in the ionospheric delay can impede the positioning performance significantly. Thus, next to the CAT-I service already operational today (called GAST-C), a new ionosphere-free dual-frequency service was drafted (called GAST-F). This service is expected to operate independently from any ionospheric disturbances using dual-frequency measurements and corrections. In order to validate both GBAS services, the total simulation was combined with the GBAS implementation in TriPos. Specific GNSS errors were modelled and implemented based on the GBAS standards. The overall performance of GAST-C and GAST-F in the presence of ionospheric anomalies was assessed with distributed Monte Carlo simulations. With GBAS taken as an example application for GNSS total simulations, GAST-F demonstrated its capability to operate independently from ionospheric threats. GAST-C on the other hand suffered significantly from the simulated ionospheric effects. Even though the number of simulations conducted is not sufficient for demonstrating all requirements, the general usability of this approach could be verified.weiterlesen