基于Radon-CPF-Fourier变换的机动目标ISAR成像

由于机动目标的逆合成孔径雷达(Inverse Synthetic Aperture Radar,ISAR)成像中存在多普勒扩散现象,易导致成像分辨率降低。针对此问题,在多分量三次相位信号(Cubic Phase Signal,CPS)模型基础上,提出一种基于Radon-CPF-Fourier变换(Radon-Cubic Phase Function-Fourier Transform,RCFT)的机动目标ISAR成像方法。RCFT可实现CPF中自项能量的相干积累,减轻多普勒扩散带来的影响。与现有的基于时频分析和参数估计的ISAR成像算法相比,RCFT的主副比性能提升了至少2 dB,在时频分辨率无损失时具备更好的自项能量积累能力,可获得更高质量的成像结果。仿真验证了所提方法的有效性。

ISAR Imaging of Maneuvering Targets Based on Radon-CPF-Fourier Transform

Due to the Doppler frequency spread in the inverse synthetic aperture radar(ISAR)imaging of maneuvering targets,the imaging resolution is reduced.For the problem,based on the multi-component cubic phase signal(CPS)model,an ISAR imaging method for maneuvering targets based on Radon-Cubic Phase Function-Fourier transform(RCFT)is proposed.The coherent accumulation of auto-terms energy in cubic phase function(CPF)can reduce the impact of Doppler frequency spread.Compared with the existing ISAR imaging algorithms based on time-frequency analysis and parameter estimation,the performance of RCFT’s peak sidelobe ratio is improved by at least 2 dB.RCFT has better auto-term energy accumulation capacity without loss of time-frequency resolution,and can obtain higher quality imaging results.Simulation proves the effectiveness of the proposed method.