Methods, systems, and devices can determine spatial relationships between a probe and a target surface. Specular reflections from the target surface vary dramatically with small changes in angle between the scanning beam and the target surface, and as the geometry of the beam scanner and light detector of the probe are often known, and as the angle of the light beam projected from a scanner for accurately generating an image, the pattern of spectral light reflected from the light beam directly back to the detector allows the distance between the probe and the target surface, and/or the angular relationship between the probe and the target surface, to be calculated.