General approach for the description of optical 3-D measuring systems

In this paper a general geometric description of the optical methods for 3-D coordinate measurement is presented. Similar to holographic interferometry this new approach is based on the concept of measuring sensitivity. As a special case the derived basic relation is applied to the fringe projection technique using a physical model of this measurement method. Moreover a geometric 3-D model that contributes to a dramatic reduction of systematic distortions of measured 3-D coordinates is presented. On the one hand this model is sufficiently general but on the other hand still easy to handle. It permits an explicit and direct determination of 3-D coordinates from primary measuring data as well as a calibration of the measuring set-up using linear identification methods mainly. The described 3-D model can be applied also with advantage to multiview registration tasks.