Zero on-site testing on GNSS for train control towards digital railways

The integration of Global Navigation Satellite System (GNSS) technology into railway train control systems is a crucial step toward achieving the vision of a digital railway. Traditional train control systems undergo extensive in-house tests and prolonged field tests for certification and approval before operational deployment, leading to high costs, delays, and operational disruptions. This paper introduces a GNSS-based train control localization framework that eliminates the need for on-site testing by leveraging train movement dynamics and 3D environment modeling to create a zero on-site testing platform. The proposed framework simulates train movement and the surrounding 3D environment using collected railway line location data and environmental attributes to generate realistic multipath signals and obscuration effects. This approach enables comprehensive laboratory-based case studies for train localization, reducing the need for physical field trials. The framework is established in house, using the data collected at the Test Base of China Academy of Railway Sciences (Circular Railway). Results from open area and cutting environment tests demonstrate high localization accuracy repeatability within the simulated environment, validating the feasibility and effectiveness of zero on-site testing for GNSS-based train control systems. This research highlights the potential of GNSS simulation platforms in enhancing cost efficiency, operational safety, and accuracy for future digital railways.