旅客人身时频调和型毫米波三维重建  

Three-dimensional reconstruction algorithm for passengers based on time-frequency coordination

作　　者：杨磊 陈英杰 王腾腾 宋昊 方澄 YANG Lei;CHEN Ying-Jie;WANG Teng-Teng;SONG Hao;FANG Cheng(Tianjin Key Laboratory for Advanced Signal Processing,Civil Aviation University of China,Tianjin 300300,China)

机构地区：[1]中国民航大学天津市智能信号与图像处理重点实验室,天津300300

出　　处：《红外与毫米波学报》2023年第3期327-338,共12页Journal of Infrared and Millimeter Waves

基　　金：国家自然科学基金(62271487)。

摘　　要：在毫米波人身安检成像中,二维平面承载的有限信息量使得安检系统对隐匿危暴/爆品的检出概率不高,亟待获取人体三维全聚焦重建结果,且以往仅时域或频域三维重建算法均难以实现精度与效率的平衡。为此,基于“维度分解-算法调和”策略提出时频调和型三维重建算法(Time-Frequency Coordination 3D Reconstruction,TFC-3DR)。该算法融合频域算法的效率与时域算法的精度优势,利用距离徙动频域成像算法(Range Migration Algorithm,RMA)的方位平移不变性,在距离-高度截面统一地校正距离徙动,以保证运算效率,而后将时域后向投影(Back Projection,BP)算法应用于距离-角度维截面,通过将脉冲压缩数据与成像空间分辨单元逐点相干积累,以保证成像精度,由此加快运算效率的同时又保证重建精度。由于BP算法的引入,阵列天线角度维扫描轨迹灵活可变,有效降低了人体侧面盲区面积,避免漏检、误检。仿真和实测人体毫米波数据实验,验证了算法的有效性与实用性,同时分析重建效果与运算复杂度,验证了该文所提算法相比三维BP重建算法的优越性。In the millimeter wave imaging of personal security inspection,it is with low probability to detect the dangerous and violent/explosive things in the limited two-dimensional imaging plane.Therefore,the human result reconstructed by three-dimensional fully focused algorithm is demanded urgently.It is difficult to achieve a balance between the accuracy and efficiency for the conventional three-dimensional reconstruction algorithms that are purely either in time or frequency domain.To this end,time-frequency coordinated three-dimensional reconstruction algorithm(TFC-3DR)is proposed based on the dimensional decomposition and algorithmic coordination scheme,in which the efficiency of frequency-domain algorithm and the accuracy of time-domain algorithm can be combined and coordinated.In order to guarantee the operational efficiency,the range migration is uniformly calibrated in the range-height plane under the azimuth invariance characteristics of the range migration algorithm(RDA)in the frequency-domain.Then,the time-domain back projection(BP)is employed in the range-angle plane through point-by-point coherent accumulation of pulsecompressed data and resolution units to guarantee the imaging accuracy.In the end,TFC-3DR is established with both high efficiency and accuracy.Due to the introduction to BP algorithm,the scanning trajectory of the array antenna in the angle dimension is flexible and variable,which reduces the blind area of the human body,so that highly missed and false detection rate can be avoided.Simulated and practical data of human body is performed to verify the effectiveness of the proposed algorithm.Meanwhile,the superiority over the proposed algorithm is examined by comparing with the BP reconstruction algorithm in terms of the reconstruction accuracy and computation complexity.

关 键 词：毫米波成像 三维重建 距离徙动算法 后向投影算法 

分 类 号：TN951[电子电信—信号与信息处理]