Research On Non-line-of-sight Target Detection And Positioning Method Using Photon Counting Lida

Non-line-of-sight detection is a laser active detection technology for targets out of field of view.It is also a research hotspot in the field of photon counting lidar in recent years,and is widely used in the fields of automatic driving,disaster rescue,environmental reconnaissance and so on.The main difficulty of non-line-of-sight detection technology is how to detect the echo signal from the complex background environment and locate the target accurately and quickly.Therefore,simulation and experiment research are carried out in this paper for the detection and location method of non-line-of-sight targets of photon counting lidar.Based on the research data,this paper describes the working principle and mode of photon counting lidar,introduces the bidirectional reflection distribution function to optimize the lidar equation of non-line-of-sight target detection,and deduces and summarizes the statistical law of full waveform signal of non-line-of-sight target detection.On this basis,the whole system simulation environment based on Monte Carlo algorithm is designed and constructed to accurately simulate the full waveform echo signal of non-line-of-sight target detection.Then write programs for different cumulative number,dead zone,time,system,background noise,target detection Angle reflection character and horizon under the optical path of the horizon detection signal echo waveform simulation research,the change rule of the at the same time as the non-line-of-sight detection performance evaluation index system of target detection rate and the analysis of signal-to-noise ratio was calculated.Then,the positioning method of elliptic back projection is introduced,and the effectiveness of the positioning method is verified by the target echo signal obtained by the whole system simulation.The results of joint positioning of different number of detection points are compared,and the positioning error and its influencing factors are analyzed.On the basis of theoretical and simulation research,this paper also designed an experimental system for detecting and locating non-line-of-sight target of photon counting laser radar,which realized the extraction of effective target signals from the fullwaveform signals detected by the system,and located the target within 1.8 meters outside the visual field with transverse and longitudinal errors within centimeters.The effects of various waveform processing methods on positioning errors are compared and analyzed.The content of this paper has some reference value for the future research and application of photon counting lidar in non-line-of-sight target detection.