Positive Train Control and GNSS Railway Enhancement
In the U.S., Positive Train Control (PTC) is a system of functional requirements for monitoring and controlling train movements is an attempt to provide increased safety. Augmented GNSS (e.g., SBAS or GBAS) may be utilized to provide reliable, continuous positioning as part of specific systems designed to meet the PTC requirements.
In Europe, the European Commission, under research program Horizon 2020, is sponsoring a project known as RHINOS, or “Railway High Integrity Navigation Overlay System,” as a starting point for integrating GNSS into the existing European and worldwide railway infrastructure to provide improved autonomy to existing mainline services and new capability in more austere regions.
Stanford has been performing research in this area to support both PTC and RHINOS by modifying techniques it helped develop for SBAS and GBAS certification for airborne users to fit the railway environment. This research includes comparing existing aviation and railway safety requirements, developing GNSS anomaly threat models that are specific to the railway environment, and the use of simulations to implement these threat models under railway conditions in order to determine the safety mitigations needed to meet railway performance and safety requirements. These research efforts are currently self-funded and supplemented through the RHINOS project.
For more information on Positive Train Control, view: PTC Wikipedia article.
For more information on European railway development—specifically the use of satellite navigation to augment the existing European Rail Traffic Management System (ERTMS), view the article: European GNSS in Action: EGNSS for Safer, Sustainable Railways, European Global Navigation Satellite Systems Agency, September 9, 2015.