Transmitters-based localization at intersections in urban environments

An apparatus comprising:

• a processor configured to execute computer-executable instructions stored on a non-transitory medium, wherein the computer-executable instructions, when executed, cause the processor to:
• receive a first Dedicated Short Range Communication (DSRC) message from a first RST located at an intersection between a plurality of streets when a vehicle is within range of the first RST, the first DSRC message from the first RST indicating the location of the first RST and when the first DSRC message from the first RST was sent;
• determine a first delta time by determining a difference between a vehicle's time of receipt of the first DSRC message from the first RST and an RST's time of transmission of the first DSRC message from the first RST;
• receive a second DSRC message from the first RST when the vehicle is within range of the first RST, the second DSRC message from the first RST indicating the location of the first RST and when the second DSRC message from the first RST was sent;
• determine a second delta time by determining a difference between a vehicle's time of receipt of the second DSRC message from the first RST and an RST's time of transmission of the second DSRC message from the first RST;
• determine a first difference of delta time by subtracting the first delta time from the second delta time;
• generate a first calculated distance propagated by the DSRC signal between receiving the first and second DSRC messages from the first RST by multiplying the first difference of delta time by the speed of light;
• and
• provide the calculated distance propagated by the DSRC signal to a vehicle-location estimator that uses the calculated distance propagated by the DSRC signal to generate a location estimate of the vehicle that is more accurate than an estimate generated without using the calculated distance propagated by the DSRC signal.