Simulation of the Functional and Performance Behavior of Multi-GNSS Constellation

The paper presents the results of forming a current almanac of Global Navigation Satellite System (GNSS) in Yuma format. This type of format use in various scenarios focused on simulating availability, geometrical dilution of precision (GDOP) and positional navigation system precision when using Galileo, GPS, Beidou systems standalone and all together inside a multi-system GNSS constellation. The Yuma format was originally used for analyzing and simulating the orbit of the GPS system, and there is a large amount of software available for analyzing the availability of satellite navigation systems based on data in this format. Due to the lack of almanacs in the Yuma format for most satellite navigation systems, specialized software was used in the research to convert data into a unified format. The evaluated availability and accuracy are important performances of GNSS that provides global coverage of signals for positioning, navigation and timing (PNT). These performances depend on structure of space segment which is number of satellite systems provide transmitting of navigation signals. The better level of PNT can be achieved by receiving data from all available systems and augmentations such as Wide Area Augmentation System, European Geostationary Over-lay Service, Indian Regional Satellite Navigation System and Qazi-Zenith Satellite System.