“GPS” would mean GNSS satellite systems like GPS, as well as terrestrial systems like AGPS and base-station-based triangulation. Given that modern train control systems involve transponders alongside the railway line, these can be used as well. Railway lines running through tunnels in particular would rely on non-satellite systems.
“GPS” would mean GNSS satellite systems like GPS, as well as terrestrial systems like AGPS and base-station-based triangulation. Given that modern train control systems involve transponders alongside the railway line, these can be used as well. Railway lines running through tunnels in particular would rely on non-satellite systems.
Rail lines use multiple redundant navigation and safety systems. GPS is one of them.