Kan Yingzhi, Zhu Yongfeng, Tang Liang, Fu Qiang, Pei Hucheng
College of Electronic Science and Engineering, National University of Defense Technology, Changsha 410073, China.
Beijing Institute of Mechanical and Electrical Engineering, Beijing 100074, China.
Sensors (Basel). 2016 Sep 19;16(9):1525. doi: 10.3390/s16091525.
In this paper, to deal with the concealed target detection problem, an accurate and efficient algorithm for near-field millimeter wave three-dimensional (3-D) imaging is proposed that uses a two-dimensional (2-D) plane antenna array. First, a two-dimensional fast Fourier transform (FFT) is performed on the scattered data along the antenna array plane. Then, a phase shift is performed to compensate for the spherical wave effect. Finally, fast Gaussian gridding based nonuniform FFT (FGG-NUFFT) combined with 2-D inverse FFT (IFFT) is performed on the nonuniform 3-D spatial spectrum in the frequency wavenumber domain to achieve 3-D imaging. The conventional method for near-field 3-D imaging uses Stolt interpolation to obtain uniform spatial spectrum samples and performs 3-D IFFT to reconstruct a 3-D image. Compared with the conventional method, our FGG-NUFFT based method is comparable in both efficiency and accuracy in the full sampled case and can obtain more accurate images with less clutter and fewer noisy artifacts in the down-sampled case, which are good properties for practical applications. Both simulation and experimental results demonstrate that the FGG-NUFFT-based near-field 3-D imaging algorithm can have better imaging performance than the conventional method for down-sampled measurements.
在本文中，为解决隐蔽目标检测问题，提出了一种精确高效的近场毫米波三维（3-D）成像算法，该算法使用二维（2-D）平面天线阵列。首先，对沿天线阵列平面的散射数据进行二维快速傅里叶变换（FFT）。然后，进行相移以补偿球面波效应。最后，在频率波数域对非均匀三维空间谱执行基于快速高斯网格化的非均匀FFT（FGG-NUFFT）与二维逆FFT（IFFT）相结合的操作以实现三维成像。传统的近场三维成像方法使用斯托尔特插值来获取均匀的空间谱样本并执行三维IFFT以重建三维图像。与传统方法相比，我们基于FGG-NUFFT的方法在全采样情况下的效率和准确性相当，并且在欠采样情况下能够获得更准确的图像，杂波更少且噪声伪影更少，这些都是实际应用中的良好特性。仿真和实验结果均表明，基于FGG-NUFFT的近场三维成像算法在欠采样测量中比传统方法具有更好的成像性能。
