A device for use in conjunction with a coordinate measuring device, a three-dimensional coordinate measuring system and a method of measuring three-dimensional coordinates are described. The device includes a light source mounted substantially within the center of a spherical member having a spherical...http://www.google.de/patents/US7248374?utm_source=gb-gplus-sharePatent US7248374 - Spherically mounted light source with angle measuring device, tracking system, and method for determining coordinates
