调频连续波(frequency modulated continuous wave,FMCW)体制的合成孔径雷达(synthetic aperture radar,SAR)具有较宽的方位向波束,运动误差在成像处理时会产生较为严重的方位空变性。对此,建立了具有三轴运动误差的信号模型;对宽波束情况下的距离和方位的耦合性以及由运动误差导致的方位空变性进行了分析;在视线向(line of sight,LOS)引入传统的频率分割算法来补偿方位空变误差,在航向将运动误差建模为包络误差与相位误差;提出了"逐方位块补偿法"来消除相位误差中的空变性。最后,通过仿真实验验证了所提算法的有效性。
Wide-beam motion compensation algorithm for micro-UAV FMCW SAR
Synthetic aperture radar(SAR)with frequency modulated continuous wave(FMCW)system has a wide azimuth beam,and the motion error will cause serious azimuth space variance in image processing.In this regard,a signal model with three-axis motion error is established,and the coupling of range and azimuth and the azimuth space variance caused by the motion error in the case of wide beam are analyzed.Then,the traditional frequency-division algorithm is introduced to compensate for the azimuth space variance in the direction of the line of sight(LOS),and the motion error in the along-track is modeled as envelope and phase error,and an"azimuth block-by-block compensation method"is proposed to eliminate the azimuth space variance of the phase error.Finally,the effectiveness of the proposed algorithm is verified by simulation experiments.
frequency modulated continuous wave(FMCW)synthetic aperture radar(SAR)azimuth space variancemicro-unmanned aerial vehicle