Zhang Ye, Deng Bin, Yang Qi, Gao Jingkun, Qin Yuliang, Wang Hongqiang
College of Electronic Science, National University of Defense Technology, Changsha 410073, China.
Sensors (Basel). 2017 Oct 24;17(10):2438. doi: 10.3390/s17102438.
In this paper, a fast three-dimensional (3-D) frequency scaling algorithm (FSA) with large depth of focus is presented for near-field planar millimeter-wave (MMW) holographic imaging. Considering the cross-range range coupling term which is neglected in the conventional range migration algorithm (RMA), we propose an algorithm performing the range cell migration correction for de-chirped signals without interpolation by using a 3-D frequency scaling operation. First, to deal with the cross-range range coupling term, a 3-D frequency scaling operator is derived to eliminate the space variation of range cell migration. Then, a range migration correction factor is performed to compensate for the residual range cell migration. Finally, the imaging results are obtained by matched filtering in the cross-range direction. Compared with the conventional RMA, the proposed algorithm is comparable in accuracy but more efficient by using only chirp multiplications and fast Fourier transforms (FFTs). The algorithm has been tested with satisfying results by both simulation and experiment.
本文针对近场平面毫米波（MMW）全息成像，提出了一种具有大焦深的快速三维（3-D）频率缩放算法（FSA）。考虑到传统距离徙动算法（RMA）中被忽略的横向距离耦合项，我们提出一种算法，通过三维频率缩放操作，对去调频信号进行距离单元徙动校正，无需插值。首先，为处理横向距离耦合项，推导了一个三维频率缩放算子，以消除距离单元徙动的空间变化。然后，执行距离徙动校正因子，以补偿残留的距离单元徙动。最后，通过横向方向的匹配滤波获得成像结果。与传统的RMA相比，该算法在精度上相当，但仅使用线性调频乘法和快速傅里叶变换（FFT）时效率更高。该算法已通过仿真和实验测试，结果令人满意。
