Easy4PNT: An easily applied multi-platform precise GNSS toolbox coded in Python using uncombined observation model

Abstract Precision positioning technologies, represented by Precise Point Positioning (PPP) and Real-Time Kinematic (RTK), are gradually gaining much more attention by GNSS workers as well as researchers from other related aspects. However, most of the existing open-source tools are compiled by C/C++, with high efficiency but low readability. Toolboxes compiled by commercial software such as MATLAB use highly readable scripting languages, but limit the free use of unauthorized users. In this paper, we released a Python-based PNT toolbox which takes advantage of language-level completely open source and rich third-party library features. Aiming at scientific research purpose, mainstream precise GNSS models and methods, such as uncombined PPP & RTK observation model, OSB products-based PPP-AR, SSR-based PPP-RTK and Real-Time PPP-B2b, are concluded in this toolbox. A series of precision GNSS positioning experiments at different times and regions are conducted in this paper: Globally PPP-AR results show that Easy4PNT can achieve positioning accuracy better than 3 cm horizontally and 5 cm vertically worldwide during the May magnetic storm, 2024; Uncombined Multi-GNSS dual-frequency RTK results show that Easy4PNT can achieve millimeter-levelkinematic positioning of 30 km baseline length and decimeter-level dynamic positioning of 900 km baseline length; PPP-RTK results show that Easy4PNT can achieve horizontal convergence better than 1 minute and 52\% higher than PPP-Float in positioning precision during the ionospheric quiet period; PPP-B2b results show that Easy4PNT has the potential for real-time PPP applications on edge Python devices. Easy4PNT is now available at https://github.com/alxanderjiang/Easy4PPP