基于距离-慢时间匹配滤波和复值反投影的快速旋转目标三维成像算法

本文针对快速旋转目标的三维成像问题，首先，建立雷达目标成像的几何模型，推导了快速旋转目标的距离-慢时间域回波信号的解析表示；其次，提出了基于匹配滤波和复值反投影的三维成像算法。该算法首先构造距离-慢时间域匹配滤波器，对滤波器参数即旋转目标的半径方向取值进行搜索，综合各参数取值处的匹配滤波结果，通过设置阈值获得目标三维位置；同时，考虑目标散射点存在遮挡、散射系数变化及低信噪比的复杂情况，匹配滤波结果将存在失配导致的目标位置展宽及虚假散射点，利用复值反投影方法消除失配影响，重建准确的目标三维像；再次，对匹配滤波的成像分辨能力进行了分析，从而确定了该算法对目标的旋转轴、半径及初始相位的分辨率和匹配滤波的参数搜索步长；最后，分别对理想及复杂情况下的目标成像进行了仿真并对比分析了匹配滤波和本文算法的成像结果，仿真结果证明了本文算法的有效性。 

Range-Slow-Time Matched-Filter and Complex-valued Back Projection-Based 3-D Imaging algorithm For Rapidly Spinning Targets

To resolve the problem of the 3-D imaging of rapidly spinning targets, firstly, this paper has constructed the radar imaging geometric model and acquired the echo analytical representation of the rapidly spinning target at range-slow-time domain; secondly, the MF-CVBP(matched filter and complex-valued back-projection)-based 3-D imaging algorithm is proposed. This algorithm constructs range-slow-time matched filter, by searching its parameter of radius direction of targets, the results of filter at each value of parameter are combined to acquire the 3-D target position; At the same time, considering the case of shadowing and varying backscattering coefficients and low SNR, the extended target position and false scatters will appear in the output of matched-filter due to mismatch, so the 3-D target image is reconstructed exactly after the influence of mismatch is eliminated by the complex-value back projection; thirdly, the resolving capability of matched filter is analyzed so as to determine the resolution of the position of rotating axis、radius and initial phase and the searching step of filter’s parameter; In the end, the radar imaging in the case of ideal and complicated environment is simulated and imaging results of the method of matched filter and MF-CVBP are analyzed, simulation results has proved the validity of the proposed algorithm in this paper.