Accurate 3-D shape measurement has played an increasingly important role in various diverse industrial applications, such as manufacturing, robot vision etc. To achieve a low cost, compact 3D profiling system, a phase shifting scheme with a single MEMS scanner has been proposed and studied by some international colleagues. In this paper, we establish mathematical model for the 3D profiling system to reconstruct surface contour of the object. A data processing flow chart is designed, and the algorithm is developed correspondingly, in which some means to improve accuracy are also taken into consideration. Then, numerical simulation for the whole work process of the profiling system is performed according to the theoretical model. The simulation results are analyzed in detail to get the optimal parameters. In order to verify the feasibility of the scheme, we build an experimental setup and carry out a series of experiments. The results show that the RMSE is about 6% and the range resolution is about a few millimeters.
Based on the work on scattering properties of laser beam in the atmosphere, we designed and made a prime coherent lidar using laser light at 1.55 μm. By using this equipment, we detected the reflected signal from a wall and scattering signal from the air. Then we tried to measure the backscattering coefficient of air in our local. However, after analyzing and calculating on the data we got, the result is not very good. We did some quantum calculation about our equipment, and gave some suggestions about how to improve it to a practical device.