The objective of this project is to study GNSS carrier phase integrity techniques for application in railway safety of life applications, and in particular, the evolution of the European Rail Traffic Management System (ERTMS) with virtual balise detection using GNSS.
Carrier phase positioning can achieve a significantly better performance than code-based positioning; however, to date there are no certified integrity concepts applicable to these techniques. Such techniques are expected to provide significantly better accuracies, enabling the use of GNSS in ERTMS operations and scenarios that are not possible today with the performance of existing GNSS code-based integrity concepts.
The tasks to be performed will include:
- Review of requirements for ERTMS related to start of mission and requirements related to the ERTMS virtual balise concept
- Review of carrier phase positioning techniques, processing modes, applicability in the railway environment and potential issues for development of a resilient integrity concept
- Safety analysis for each candidate positioning technique
- Proposing integrity algorithms for mitigation and bounding residual errors for candidate positioning techniques
- Experimentation and verification of integrity algorithms using railway measurement data sets.
Telespazio UK’s role within this project consortium involves the following:
- Review and consolidation of positioning requirements for virtual balise detection in ERTMS
- Technology assessment and review of state-of-the-art of methods for detection and mitigation of local feared events
- Proof of concept requirements specification
- Definition of test scenarios and experimentation plan
The results of the activity will, amongst others, provide recommendations for suitability of techniques supporting resilience for high-integrity train control applications, identifying gaps and future work.