Systems and methods for communicating with vehicles using radar

A system for communicating information to vehicles, comprising:

• at least one spatially-encoded marker coupled to a traffic light;
• and
• a vehicle having at least one controller and a radar, the radar configured to transmit a radar signal and receive returns of the radar signal from the at least one spatially-encoded marker, the at least one controller configured to determine a message comprising a radar signature encoded by the spatially-encoded marker based on the returns;
• wherein the at least one spatially-encoded marker comprises a moveable element and an actuator coupled to the movable element, wherein the actuator is configured to move the moveable element, and wherein the at least one controller is configured to determine the message based on a relative position of the movable element;
• wherein the at least one controller is configured to determine a value indicative of the relative position of the moveable element, and wherein the at least one controller is configured to determine the message based on the value;
• wherein the message conveys a current state of a traffic light signal of the traffic light;
• wherein the at least one controller is configured to
• determine a location of the at least one spatially-encoded marker within a local coordinate system based on the message,
• determine a location of the at least one spatially-encoded marker relative to the vehicle based on the returns, and
• determine a location of the vehicle within the local coordinate system based the determined location of the at least one spatially-encoded marker within the coordinate system and the determined location of the spatially-encoded marker relative to the vehicle.