Computer simulation study of distance uncertainty in laser triangulation

In industrial applications some single point laser range sensing systems by triangulation are often used. There are many algorithms to determine the center position. But there are basic physical limits of accuracy of center position which is introduced by laser speckle on image. In this paper we conduct a computer simulation on the intensity distribution and gravity of image speckle pattern produced under the completely coherent illumination, and give a direct result on some possible factors such as the observation aperture of an imaging system, the surface roughness, the number of microtopology units included in the point spread function and the width of illumination area The result confirms the dependence of distance uncertainty on the observation aperture of an imaging system. A comparison between the simulation and earlier theoretical results is also given.