| With the increase of terrorist activities,people pay more and more attention to the security inspection of public places.As a new type of imaging technology,millimeter-wave imaging has attracted more and more attention in recent years.The frequency of the millimeter-wave is located between the microwave and the far infrared wave,which has a certain penetration.Compared with the traditional security inspection equipment,millimeter-wave can not only detect concealed metal contraband,but also detect concealed non-metallic contraband,and it has no ionization and no harm to human body.Based on the characteristics of millimeter wave,millimeter-wave imaging will have a relatively large market in the field of security inspection.Based on the application of millimeter-wave in the field of security inspection,the content of millimeter-wave imaging algorithm is carried out in this thesis.On the basis of the study of the short range active millimeter-wave plane scanning imaging,we have further expanded the study of the short range active millimeter-wave cylindrical scanning imaging,the in-depth analysis is carried out from the theoretical point of view,and the related imaging algorithm is simulated and verified,the main research contents are as follows:(1)The basic theory knowledge of millimeter-wave imaging is discussed,the characteristics of stepped frequency signal and the choice of antenna scanning mode are introduced,the characteristics of millimeter-wave security imaging system are analyzed.(2)The research of millimeter-wave plane scanning imaging technology.The system model and the principle of the range migration imaging algorithm are analyzed,the imaging simulation of single point target,multi point target and shaped target are carried out,and the effectiveness of the algorithm is verified,and the experimental imaging of two sides of the human body was carried out by using the measured data of human body.(3)The research on wave-number domain algorithm in millimeter wave cylindrical scanning imaging.In view of the fact that plane scanning can only detect the information on both front and back of the human body,while the side information may be missed,the research on millimeter-wave cylindrical scanning imaging is carried out,a wave-number domain algorithm for millimeter-wave cylindrical scanning imaging isfurther studied,the system model is analyzed,and the imaging principle,sampling criterion and resolution are derived.The validity and feasibility of the wave-number domain algorithm for millimeter-wave cylindrical scanning imaging are verified by the accurate simulation results of different target scenes. |
PDF Full Text Request