Study On Array Optimization Method Of Cylindrical 3D Imaging

In recent years,criminals have made use of convenient transportation to smuggle,with severely damaged the peace and stability of society.So relevant research institutes and enterprises around the world have researched and development of related security inspection equipment,and achieved a lot of results.Among the many security inspection equipment,millimeter-wave cylindrical 3D imaging has been more widely researched and applied in the field of security inspection due to its advantages of omnidirectional,clothing penetration,high resolution imaging and non-ionizing radiation.However,the existing cylindrical 3D imaging array mainly get the radar echo data through the linear array + mechanical scanning way.Due to the mechanical scanning method,the array data acquisition time is relatively long.In the area of rapid flow of people,the efficiency of its passage is limited,and there is an urgent need to develop a new imaging mechanism for efficient data acquisition.So this paper researches a new system of sparse cylindrical imaging and proposes a 3D imaging algorithm based on orthogonal frequency.The specific research work is as follows:1.Aiming at the problem of low data acquisition efficiency in the existing cylindrical 3D imaging,a cylindrical 3D imaging array imaging mechanism based on orthogonal frequency division is proposed,which combines with the transmission and reception mechanism of orthogonal frequency division,and transmits different frequencies through different array elements that to realize frequency division multiplexing.It improves the data acquisition efficiency.The imaging mechanism takes into account the sparse array element layout and equivalent full array sampling,which is of great significance to improve the system data acquisition efficiency.2.Aiming at the problem of sparse optimization of the antenna of the cylindrical 3D imaging array,the optimization method of the sparse cylindrical 3D imaging array is studied.A sparse optimization model of a sparse cylindrical 3D imaging array with full consideration of the equivalent quasi-single-station phase error and wavenumber width is constructed.On the premise of ensuring that the sampling meets the sampling criteria,the optimal solution for sparse array optimization is obtained,which greatly reduces the number of elements in the cylindrical array.Verification through simulation provides an important reference for reducing system hardware costs.3.Aiming at the problem of high-precision 3D imaging focusing of sparse cylindrical array,a 3D confocal projection algorithm suitable for orthogonal frequency division sparse cylindrical is proposed.First,the algorithm meshes the Region of Interesting(ROI);Then,the algorithm establish a matching function between each pixel and each effective observation transceiver antenna;On this basis,the matching process is performed to obtain the amplitude and phase information of the corresponding pixel;Finally,all the amplitude and phase information collected are coherently superimposed to obtain the scattering coefficients of the corresponding pixels,and the effectiveness and correctness of the algorithm are verified by point target simulation.