Increased accuracy from a three-dimensional movement-tracking system

This report describes the methods used to improve the performance of a three-dimensional movement-tracking system that is based on infrared cameras and light-emitting diodes. The technique has general application to similar systems with other types of cameras. The improvement was obtained by postprocessing to correct camera-image distortions. This procedure yielded a six-fold increase in accuracy. With a 900-mm-cube viewing volume, the error in locating a point was reduced to less than 3 mm.