频率步进雷达机动目标运动参数估计及成像

Motion parameters estimating and imaging of maneuvering targets in stepped-frequency radar

为了解决频率步进雷达目标的复杂径向运动参数估计及补偿问题,提出用基于随机自相关函数的联合调频傅里叶变换方法精确估计目标复杂运动参数。目标回波信号与本振信号混频后,可以表示成离散的高阶线性函数,将其进行随机自相关运算,并在脉内作联合调频傅里叶变换,同时在脉间进行相干累积,根据峰值位置获得径向运动参数的精确估计,实现低信噪比条件下目标运动补偿和清晰成像。计算机仿真实验结果显示,该方法能够在-25dB低信噪比下清晰成像,通过比较表明,该方法具有较好的抗干扰能力。

To address the problem of accurately estimating and compensating complex radial motion param- eters in stepped-frequency radar targets, a method of joint chirp-Fourier transform based on random auto- correlation function was proposed. The target echo after mixing the vibration signal can be regarded as a discrete high-order linear function, which can be employed to coherent integration between intra pulse after using random autocorrelation operation in pulse and joint chirp-Fourier transform. Through accurate esti- mation of target complex radial motion parameters, the target motion compensation and clear imaging can be achieved under the low signal noise ratio（SNR）. The simulation results show the methods can clear imaging with SNR --25 dB. Comparison shows that the proposed method is capable for restrain interference.