Abstract: A method and apparatus is provided for calibrating distance measuring instruments, in particular, optical three dimensional measurement sensors. The method is not restricted to aligning the motion of the calibrating surface to be parallel to the sensor centerline. Accordingly more than one sensor can be present during the calibration procedure. This leads to the practicality of aligning multiple sensor systems using a common translation stage for all sensors or using translation stages that are a part of the system. The joint calibration of sensors embedded in a system guarantees proper registration without additional steps. A method for calibrating optical sensors to accuracies approaching the wavelength of light is given.