Methods for Optical Shape Measurement and their Measurement Uncertainty

There is a wide spectrum of optical 3-D sensors based on only a few basic principles. We calculate the measurement uncertainty for several "paradigm" methods, by means of the Cramer-Rao lower bound. It turns out that when all other sources of noise are neglected, the shot noise becomes the ultimate limit of the measurement uncertainty and the measurement uncertainty can be traced back to a Heisenberg uncertainty product. Consequently, making one of the factors uncertain, the other factor will become more precise. The different methods vary only by the way how this "uncertainty" is generated.