A structured light assurance system for a head tracking system is disclosed. In embodiments, the structured lighting system includes structured light projectors mountable in an aircraft cockpit or other mobile platform, the projectors oriented toward a pilot or operator of the mobile platform for capturing three-dimensional (3D) imagery of the pilot (e.g., via offset imaging sensors) and determining from the captured 3D imagery a position and orientation (pose) of the pilot's head relative to the mobile platform and independent of the main headtracking system. The structured lighting system verifies the determined head pose (and may also self-calibrate) by identifying within the captured imagery static fiducial markers fixed to the cockpit in known locations. The structured lighting system forwards the determined head pose to the main headtracker for drift correction or initial head pose updating by the latter system.