Research On 3D Imaging Algorithm In Active Millimeter Wave Security System

With the increasing intensities of terrorist activities,security inspections in public places such as airports,customs and railway stations have been paid more and more attention by all countries in the world,and the requirements for the accuracy,real-time and intelligence of security systems have been put forward.Based on the limitations of traditional security measures,we urgently need more efficient,safe and humane security means.In recent years,due to the advantages of millimeter wave imaging technology,such as simplicity,high efficiency and security,it has attracted more and more attention in security imaging.At present,the algorithms commonly used in millimeter-wave imaging are synthetic aperture imaging algorithms,single-frequency and wide-band holography.The three-dimensional image is more intuitive than the two-dimensional image to establish the detailed information of the imaging target,and it can better reflect the advantages of the algorithm.This paper focuses on the 3D millimeter-wave algorithm with high imaging resolution,good image quality and short imaging time.The important research contents are as follows:(1)to study the imaging scheme which can be applied to the security imaging system,and to introduce the characteristics of the LFM signal and the step frequency signal,the derivation process and the imaging step of the imaging algorithm are described in detail.And summarizes the key parameter design index and imaging quality evaluation index of active millimeter wave 3D imaging.(2)to get high image resolution.The detailed resolution of the system distance resolution is simulated and extended to the spatial resolution of the three dimensions of the horizontal x direction,the vertical y direction and the vertical z direction in the three-dimensional imaging.It provides reference for the parameter settings of imaging,so as to better serve the security imaging system.(3)to solve non-uniform data problem in 3D-imaging.Stolt interpolation technique is used to solve the problem of inhomogeneity of the measurement point of the actual imaging at the spatial frequency interval.The point target images and complex target scene images are reconstructed in 30-40 GHz band,and the feasibility of the 3D imaging algorithm based on Stolt interpolation is analyzed.(4)The image post-processing technique is applied to the 3D millimeter-wave image processing.On the basis of ensuring the imaging time,the image quality of the reconstructed image is improved and the better imaging result is obtained.Through the study of the above,we can enrich and develop the millimeter-wave short-range three-dimensional imaging technology,so that it can be better applied in the security imaging system,with higher 3D imaging resolution,better image quality,shorter imaging time.Finally provide theoretical support and technical guidance for the development of 3D millimeter-wave imaging system in the field of security.