Research On Measurement For The Laser Radar Cross Section Of Complex Full-scale Target

In modern military applications,laser radar is considered as an indispensable equipment for future combat aircraft because of its strong anti-interference ability and good concealment.The magnitude of laser beam interception and reflection by laser radar cross section(LRCS)targets.Therefore,whether it is the design of lidar system or the performance evaluation of distance measurement,it is of great value to grasp the characteristics of target laser scattering.At present,the measurement of the target laser characteristic is only applicable to the sample and scale models,the simulation modeling and the sacle-down test cannot obtain accurate target laser characteristic.For large-scale space target measurement,the laser radiation and echodetection performance of the measurement system need to reach higher requirements due to the change of the target scale.Due to the variation of measurement conditions,the Gaussian beam characteristic will bring a lot of measurement errors.Therefore,the existing measurement system cannot satisfied with the assessment requiremengts for space target LRCS.It is necessary to carry out the research on the target laser characteristic measurement technology in full scale field.In this paper,Gauss beam theory,laser radar ranging principle and LRCS theory are used to analyze the laser beam characteristics,beam shaping method and target LRCS contrast measurement method.In this paper,a measurement system for measuring large scale space target lidar cross section is designed.The main work of this paper is as follows:1.The theoretical analysis of the uniform characteristic of Gauss beam of laser.Based on the Gauss beam theory,the homogenization process of Gauss beam is simulated numerically based on two element microlens array.The results show that the optical transmitting antenna can achieve 5 degree of field of view and 98% illumination uniformity,and is suitable for detecting the full scale target echo energy.2.The echo power on the target of the laser radar is calculated and simulation experiments.The results show that the echo power to meet therequirements for receiving a remote echo signal system.A system for measuring laser echo spot parameters is set up,and the spot parameters are analyzed in detail.3.A LRCS measurement system for complex Full-scale target is built.In the experiment,matting cloth is adopted to reduce the background noise,optimize the experimental process,shorten the experimental time,and reduce the influence of the atmospheric change on the measurement.The comparison between simulation results and experimental data,in addition to first head-on and small view angle range,LRCS measurement results and simulation data are basically consistent,verify the feasibility of the measurement system for testing the laser scattering characteristics of complex targets and grasp the full scale building space laid the foundation for the comprehensive evaluation standard of LRCS system.