Abstract: A retro-reflective marker comprising a bare retro-reflective layer; a protective layer with a near-infrared (NIR) wavelength specific anti-reflective coating; and a border with an NIR absorbent coating.

Abstract: Tracking system for tracking one or more reflective markers includes at least two optical sensors configured to obtain image data of an environment that includes at least one marker. The tracking system obtains the image data from the at least two optical sensors. The tracking system is configured for extracting, from the image data, optical signatures representing reflections of the optical signal from at least one marker, determining optical centroids of the optical signatures of the at least one marker, estimating an initial pose for at least one marker, determining offset error vectors from the optical centroids of the at least one marker based on the initial pose, determining corrected optical centroids based on the offset error vectors and the optical centroids, and determining a corrected three dimensional position of the marker in the environment based on the corrected optical centroids of the marker.

Abstract: A marker for an optical tracking system includes an object having a curved surface and a plurality of beads adhered to the curved surface with an adhesive. The beads of the plurality of beads are configured for being retroreflectors. A bead of the plurality of beads can include a first portion having a reflective surface and a second portion that is substantially transparent. The first portion of the bead is oriented toward the curved surface of the object. The second portion of the bead is oriented away from the curved surface of the object. The beads are applied to the marker. A bead of the plurality of beads can be transparent and embedded in a reflective medium on the marker surface.