Optical Active Detection And Tracking System For Long-distance Targets

Modern optoelectronic technology has developed rapidly and is increasingly used in the military field.How to quickly and effectively detect and discover enemy weapon systems has become a research hotspot in the field of optoelectronic countermeasures.The laser active detection technology based on the "cat's eye" effect is an effective means for the detection of optoelectronic and traditional observation/targeting systems.The "cat's eye" effect refers to the use of a laser beam to irradiate an optical system.Since the optical convergence system of the optical system acts on the reflected light of the imaging plane of the system,a strong light reflection echo phenomenon is generated according to the reversible principle of the optical path.The "cat's eye" effect produces an echo intensity that is 2-4 orders of magnitude higher than the echo intensity at the time of diffuse reflection.Combined with the practical application of the laser active detection system based on the "cat eye" effect,this thesis has carried out theoretical research,computational derivation,simulation,experimental verification and other aspects of research work.Firstly,the paper establishes the physical model of the "cat's eye" effect.Using the combination of Fourier optics and matrix optics,the characteristics of the echo direction under normal incidence and oblique incidence are analyzed,and the return signal is returned according to the original optical path.By using the method of geometric optics,the mathematical model of the "cat's eye" effect is constructed,and the mathematical expression of the echo power in the ideal case is obtained.The effects of different incident angles and defocusing on the echo power are considered.On this basis,the paper simulates the different influencing factors and obtains the relationship between the relevant physical quantities and the echo power and the maximum detection distance.The paper also established a model of "cat's eye" target in ZEMAX software,and carried out simulation,giving the influence of beam quality,defocusing amount and incident angle on the "cat's eye" effect,especially considering the atmospheric transmittance,positive and negative effects.The influence of factors such as defocus has yielded valuable conclusions.The paper establishes an experimental device based on cat's eye effect for photoelectricsystem detection.A series of experiments are carried out.The transmitting and receiving coaxial optical path system are designed.The echo signal is detected by APD avalanche diode.The detected optical power,distance and incident angle are analyzed.The influence of different factors on the echo power is verified and the preliminary analysis and quantitative research are carried out through experiments.Based on the experimental data,the paper designs and implements the prototype of the longdistance optical detection system,scans the space through the scanning galvanometer,and controls it with the single-chip microcomputer to realize the automatic scanning and positioning of the "cat's eye" target.To lay the foundation for further development of engineering prototypes.