基于常规多普勒滤波器组结构的合成宽带距离像性能分析

Analysis of Synthetic Wideband Range Profile Based on Conventional Doppler Filter Banks

为了消除散布效应对宽带信号的不利影响,可以利用多个窄带信号合成宽带信号;同时,通过在子带内处理相干脉冲串,可进行杂波抑制、目标速度估计和区分不同速度的目标。然而,在子带内分别使用常规多普勒滤波器组,会引进多普勒散布效应所造成的输出失配误差,从而造成合成距离像的失真。分析了多普勒散布效应与子带常规多普勒滤波器组输出失配之间的关系,推导了运动目标通过滤波器组后所成高分辨距离像的距离走动公式,给出了适合子带常规多普勒滤波器组的目标速度临界值。仿真实验验证了以上结论。

In order to prevent the deleterious effects of dispersion for wideband signals, a wideband signal can be synthesized by combining coherently several individual narrow band components; meanwhile, clutter mitigation as well as estimation and discrimination of target velocity is enabled by processing the coherent pulse trains in each subband. However, the separate and independent processing using conventional Doppler filter banks in a subband can introduce deleterious effects of target Doppler dispersion among subbands and cause distortion on synthesized one-dimensional range profile. This article first analyzed the mismatch outputs of Doppler filter banks caused by target Doppler dispersion among subbands, and then derived an equation to calculate the shift of high resolution range profile for moving targets and obtained a critical velocity suitable for conventional Doppler filter banks. The conclusion is verified by simulation results.