High assurance head tracking system incorporating ground truth fiducials

A high-assurance headtracking system for a head worn display (HWD) incorporating ground-truth fiducials is disclosed. In embodiments, the headtracking system includes a camera fixed to a mobile platform (e.g., an aircraft cockpit) and oriented toward a pilot wearing the HWD. Images captured by the camera detect fiducial markers attached to the HWD (and fixed in a device reference frame) and static fiducial markers fixed to the mobile platform, each static fiducial marker including a constellation of individual markers having a known position and orientation in the platform reference frame. The headtracking system include control processors for analyzing the images and identifying therein the device-frame and static fiducial markers. The headtracking system determines a device pose of the HWD relative to the platform reference frame and monitors the device pose for drift or error based on the known positions of the identified static fiducial markers.