Restriction on the arrangement of laser trackers in laser trilateration

Abstract

Laser trilateration is an effective technique for measuring three-dimensional coordinates. Taking advantage of a fourth laser tracker, the positions of all four laser trackers can be determined by a self-calibration algorithm. We show a restriction on the arrangement of laser trackers, namely, no tracker must exist on the plane defined by the other three trackers. A method of evaluating the measurement results is also discussed.