Geiger Mode APD Array Lidar System Research On Simulation Software

The geiger mode APD array lidar system is a new type of non-scanning lidar system.Because of its single-photon detection accuracy,it has the advantages of low laser pulse energy,long detection range,fast response speed and other advantages,it is increasingly widely used in the field of lidar imaging.At present,the geiger mode APD array lidar system is in the development stage in China.In order to study the imaging characteristics of lidar,it is indispensable to carry out research on the simulation software.The purpose of this thesis is to establish a simulation software based on the geiger mode APD array lidar system and generate the geiger APD lidar detection data through simulation,so as to save the cost of the lidar system research and provide more experimental data.Based on geiger mode APD array lidar ranging equation,the simulation software considered noise components such as dark count noise,background radiation noise,crosstalk noise,fixed value noise,and laser pulse illumination energy distribution inhomogeneity,and used LOWTRAN7 calculate the atmospheric transmissivity under different weather conditions,obtained the geiger mode APD array accurate models of the laser radar system.According to the simulation model,two simulation methods are established: the simulation method based on the target 3d model and the simulation method based on the real data inversion.Both methods can realize single-frame simulation,multi-frame simulation and sequence simulation.Finally,the simulation software is developed and tested on Matlab GUI platform.The thesis proposes four evaluation indicators: leakage alarm probability,false alarm rate,noise ratio and trigger rate,which are used to evaluate the accuracy of simulation data.Given the 3d model,the simulation results of different models,different perspectives,different weather,different laser energy and different noise are analyzed.Because no detailed weather conditions were recorded when real data were collected and the parameters of the real laser detection system were incomplete,the simulation data generated in a similar environment could only be compared with the real data of 1000 frames.Except the leakage alarm probability was controlled at 6%,the error of the other three indicators reached about 18%.For the simulation method based on real data inversion,four technical indexes of 1000 frames of real data and the simulated data obtained from the inversion are compared,and the deviation between the two is 0.41% and 17.8% respectively.The experimental results prove the correctness of the two simulation methods and the practicability of the simulation software.The simulation software can well simulate the detection process of geiger mode APD array lidar,and has certain guiding significance for the process of system understanding,data generation and lidar performance prediction.