Research And Experiments For Visibility By Micro-pulse Lidar (MPL)

An eye-safe, mobile micro-pulse lidar prototype system has recently been integrated. The design of this compact system is described in detail. This system is bi-axial. By analyzing different kinds of laser pump and laser crystal, and calculating backscattering signal of different wavelength, we use a laser with high repetition rates(2KHz), micro-joule pulse energy, Nd: YAG 532nm as transmitter. The receiver is a compact Schmidt-Cassegrain telescope. PMT works on photon counting mode, in this case the system can detect more than 5km easily in clear day by 10,000 pulses accumulation. The whole system can be fitted into a small van fitted for field observations.Based on parameters of this micro-pulse lidar system, this paper presents the simulated calculation for atmosphere backscatter signal detected by Micro-pulse lidar(MPL). The simulation results have been proved by the measurements results with the real MPL. Effects of MPL system parameters such as laser energy, number of laser pulses, filter bandwidth and field of view on signal-to-noise ratio for the signal of MPL have been discussed and analyzed.The main objective in building this system is for visibility measurements in airports. Many algorithms of visibility inversion using lidar signal are described in detail. Also this paper discusses the applicability and limitation of these algorithms. At last the measurement results are showed.