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加速度会使目标回波信号的频谱展宽甚至偏移,使传统脉冲雷达测速方法不能准确估计信号的多普勒频率.为了克服目标的加速度对脉冲雷达测速的影响,提出了一种基于经验小波变换(EWT)的径向加速度估计算法.对回波信号进行EWT变换和能量型频率主成分提取方法得到回波信号瞬时频率,并利用抗差最小二乘拟合得到相位高阶系数,进而估计目标径向加速度.利用估计的加速度对信号频谱进行补偿就能准确估计信号的多普勒频率.仿真表明EWT方法是一种高精度快速算法,且估计误差最接近待估参数的C-R下界.实测高速飞行器脉冲雷达I/Q数据验证表明,EWT算法估计的加速度精度优于0.4 m/s2.该算法可应用于脉冲雷达实时加速度估计.
Acceleration makes the spectrum of the target echo broaden or even offset, so that the traditional pulsed radar velocimetry can not accurately estimate the Doppler frequency of the signal.In order to overcome the influence of the target acceleration on the pulse radar velocimetry, a wavelet transform based on empirical wavelet transform (EWT) radial acceleration estimation algorithm.EWT transform and energy-based frequency principal component extraction method of echo signal to obtain the instantaneous frequency of echo signal, and the use of robust least square fitting to get the phase higher order coefficient, and then to estimate the target Radial Acceleration The Doppler frequency of the signal can be accurately estimated by compensating the signal spectrum with the estimated acceleration.The simulation shows that the EWT method is a high precision and fast algorithm and the estimation error is closest to the CR lower bound of the parameter to be estimated. The I / Q data validation of the pulse radar shows that the acceleration accuracy estimated by the EWT algorithm is better than 0.4 m / s2, which can be applied to the real-time estimation of pulse radar.