The base of the articulated arm, the calibration bar and the OPTOTRAK cameras were all placed in rigid mounts as illustrated in app_over. Three calibration trials were undertaken, each with the calibration bar at different positions and orientations with respect to the FARO arm and OPTOTRAK to ensure maximum coverage of the arm's workspace. For each, the following procedure was performed:
Fifty FARO arm data samples for the position of each hole were extracted from the stationary portions of the calibration data (i.e., when the operator had his hands removed from the probe), and the same number of OPTOTRAK data samples of each of the four LEDs were extracted in a similar manner.