FARO Technologies, Inc.
ROBUST RETROREFLECTIVE PHOTOGRAMMETRY MARKERS

Abstract:

A retroreflective marker assembly. The assembly includes a retroreflective marker and a protective window through which light passes to reflect from the marker. A support structure supports the marker on its face and includes one or more legs, each having a facet that polarizes light upon reflection from the facet. The assembly can include a spherical base with a reflective coating secured to the base. An angular position of the marker with respect to an imaging device is determined by measuring a first angle of a light between the marker and the imaging device along a deviated optical path, determining an angular deviation of the light from a straight-line path, and determining a second angle indicative of the straight-line path based on the first angle and the angular deviation. A polarization angle of light reflected from a facet determines an orientation of the marker with respect to the imaging device.