Robust calibration of the position of reference targets for a six degrees of freedom pose sensor

This paper describes a procedure for establishing the position of a field of reference targets. The targets are the fixed references for a six degrees of freedom pose sensor. The targets are small sources of light and are observed in real time by the pose sensor. The procedure is rapid, robust to reflections of the targets, and simple for the user to perform. The pose sensor itself is used as the principle tool during the calibration process, with the only other requirement being to make at least one measurement of distance in order to set the scale of the calibrated target field. The sensor is taken to a number of locations through the target field, data collected and the position of each observed target determined. Accuracies of a few millimetres are achieved within a space of 10 metres.