The structured light system composed of three 1-D laser sensors with a vision camera showed accuracy of less than 3mm at a distance of 30m distance in outdoor. Although the proposed system have competitive performance compared to expensive DGPS and 3-D laser scanners in measuring 6-DOF motion of object, the system has more points to be improved by optimizing the structure of sensors assembly. Simulation showed much better accuracy when the structure is geometrically optimized.