APPPOLO: A Brazilian Processing Software for Multi-GNSS Precise Point Positioning

Abstract. This paper presents the development and evaluation of a Brazilian software for Precise Point Positioning (PPP) using multiple Global Navigation Satellite Systems (GNSS). The tool, named APPPOLO (Advanced Precise Point Positioning software for Optimized Localization), was designed to support advanced modeling and flexible configuration for academic and applied research in GNSS positioning. A specific performance analysis was conducted focusing on multi-GNSS PPP solutions using data from Brazilian continuously operating GNSS stations. The assessment examined the impact of different GNSS constellation combinations on positional accuracy and convergence time. The results demonstrate significant improvements in both accuracy and convergence when integrating GPS, GLONASS, Galileo, and BeiDou, compared to standalone systems. This paper contributes to ongoing efforts to develop robust, locally adapted GNSS processing tools capable of addressing atmospheric and infrastructural challenges found in South America.