Research On Method Of Cylindrical Aperture 3D Imaging Based On Single Input Multiple Output Array

In recent years,the international security situation has become increasingly severe,and the increasing number of terrorist attacks has attracted great attention from domestic and foreign governments to public safety.This makes timely improvement of security technology particularly important.Compared with traditional security inspection technology,radar 3D imaging technology has become an important research topic in the field of security inspection in recent years due to its penetrability,safety,accuracy,and efficiency.Among them,cylindrical aperture 3D imaging has become one of the main security inspection modes due to its advantages of large observation range and high resolution.The traditional cylindrical aperture 3D imaging mainly uses a single transmitter and receiver to achieve multi-phase center synthesis one by one,and then obtains information from the target area,resulting in a long overall transmission time and low efficiency.Therefore,the paper focuses on improving the efficiency of data acquisition while maintaining the same radar resolution.The details are as follows:1.The imaging principle of conventional cylindrical aperture single transmitter single receiver array is introduced,the three-dimensional imaging geometric modeling based on subband synthetic cylindrical aperture single transmitter multiple receiver array is established,the transmission and reception mechanism of cylindrical aperture three-dimensional imaging signal is given,the sampling criteria and resolution of cylindrical aperture three-dimensional imaging system are derived,and the performance indicators for evaluating the image quality of cylindrical aperture are described.2.A new 3D imaging mode for cylindrical aperture single transmitter multiple receiver array based on subband synthesis is proposed to address the issues of using more array elements and long data transmission and reception time in the layout of single transmitter single receiver array antennas;This paper discusses the formation process of the equivalent phase center of a single launch multiple receiver cylindrical aperture,derives the analytical expression of the effective synthetic aperture angle in detail,and provides the relationship between the subarray width and the effective synthetic aperture angle;According to the arrangement rules of the array elements,a layout model of the subband synthetic cylindrical aperture single transmitter multiple receiver array antenna was established.Based on this model,two array transmission and reception working modes were discussed,and the optimal solution for their array layout was obtained;Finally,a 3D imaging simulation experiment was conducted to analyze and verify the correctness and effectiveness of the new mode.3.In response to the problem that traditional imaging radars cannot directly achieve ultra wideband echo signals,a 3D BP imaging algorithm based on subband synthesis is proposed by introducing ultra wideband subband synthesis technology;This paper introduces the generation and characteristics of frequency modulated continuous wave radar signals,derives the sub band synthesis formula for one-dimensional range imaging radar,and simulates the results to analyze the improvement effect of range resolution of the synthesized signal;By compensating for the residual video phase(RVP)term of the echo,the corrected intermediate frequency signal is obtained,and then the subband is synthesized through frequency shift,stacking,and upsampling.The 3D BP imaging algorithm based on subband synthesis is derived,and the simulation experiment of the 3D BP imaging algorithm for subband synthesis of multi-point targets is conducted.The data indicators and imaging effect are analyzed to verify the correctness and effectiveness of the imaging algorithm.