Hybridized-GNSS Approaches to Train Positioning: Challenges and Open Issues on Uncertainty

Area of Science:

• Railway Engineering
• Satellite Navigation Systems
• Telecommunications

Background:

• Autonomous railway traffic and train positioning systems are increasingly adopted.
• Global Navigation Satellite System (GNSS) signals are being tested for reliability in this domain.
• Strict safety and accuracy requirements necessitate hybrid positioning solutions.

Purpose of the Study:

• To examine different hybrid positioning approaches for the railway sector.
• To evaluate the uncertainty of attained results and performance in these hybrid systems.
• To identify open issues for future research in railway positioning.

Main Methods:

• Review of various hybrid positioning strategies for railways.
• Analysis of uncertainty evaluation methods for positioning measurements.
• Comparison of approaches considering the Guide to the Expression of Uncertainty in Measurement.

Main Results:

• Hybridization of GNSS with emerging technologies like 5G is a promising approach.
• Inconsistent reporting of measurement uncertainty complicates fair comparison of solutions.
• Current methods often do not align with the Guide to the Expression of Uncertainty in Measurement.

Conclusions:

• Standardized uncertainty evaluation is crucial for comparing railway positioning solutions.
• Further research is needed to address open issues in hybrid positioning systems.
• Reliable and accurate positioning is essential for the future of autonomous rail transport.