Chai Shougang, Chen Weidong, Chen Chang
Key Laboratory of Electromagnetic Space Information, Chinese Academy of Sciences, University of Science and Technology of China, Hefei 230027, China.
Sensors (Basel). 2014 Jun 17;14(6):10664-79. doi: 10.3390/s140610664.
For high resolution imaging of a non-cooperative moving target, this paper proposes a sparse fusion imaging method. The imaging system contains two radar stations, which are separated by a certain bistatic angle and configured in a transmitter/receiver-receiver (T/R-R) manner. Consequently, two synthetic apertures are obtained at the same time from different aspect angles. By coherently fusing the echoes of the two radars, a virtual aperture spanned by these two sub-apertures can be constructed, which is larger than either of the sub-apertures; thus, the cross-range resolution of the image is enhanced. Moreover, the fusion of the echoes is realized by exploiting the sparse scattering property of the target. Then, based on the maximum a posteriori (MAP) criterion, the T/R-R fusion imaging problem is converted into a sparse signal recovery problem with unknown parameters. Finally, it is solved in an iterative manner, which contains two steps, i.e., sparse imaging and parameter estimation. Simulation results show that the proposed sparse fusion imaging method can improve the cross-range resolution significantly compared to inverse synthetic aperture radar (ISAR) within the same coherent processing interval (CPI).
针对非合作运动目标的高分辨率成像，本文提出了一种稀疏融合成像方法。成像系统包含两个雷达站，它们以一定的双基地角分开，并采用发射机/接收机 - 接收机（T/R - R）方式配置。因此，可同时从不同视角获得两个合成孔径。通过对两个雷达的回波进行相干融合，可构建一个由这两个子孔径跨越的虚拟孔径，该虚拟孔径大于任何一个子孔径；从而提高了图像的横向分辨率。此外，利用目标的稀疏散射特性实现回波融合。然后，基于最大后验（MAP）准则，将T/R - R融合成像问题转化为具有未知参数的稀疏信号恢复问题。最后，通过包含稀疏成像和参数估计两个步骤的迭代方式求解。仿真结果表明，与逆合成孔径雷达（ISAR）相比，所提出的稀疏融合成像方法在相同的相干处理间隔（CPI）内可显著提高横向分辨率。
