A localization system for a vehicle running on a guideway including portions obscured from satellite view has a number of GNSS receivers placed at strategic locations along the guideway in view of navigation satellites. GNSS transmitters retransmit received GNSS signals along an obscured portion of the guideway. Coded targets are placed at known locations along the guideway. A GNSS receiver on the vehicle picks up GNSS signals directly from the navigation satellites or retransmitted from the GNSS transmitters when on an obscured portion of the guideway. A proximity sensor on the vehicle detects the coded targets. An on-board computer synchronizes the location obtained from the GNSS signals with the location obtained from the proximity sensor. The vehicle is thus able to determine its position even in an obscured portion, such as a tunnel.