基于二维映射的LFMUWB雷达动目标速度估计

Velocity Estimation of Moving Target Based on Two-dimensional Projection for LFM UWB Radar

针对线性调频超宽带雷达动目标存在的距离-多普勒耦合以及多普勒色散对测速的影响,该文采用了频率-多普勒平面的2维映射方法。首先将接收的脉冲串回波,通过快-慢时间的2维傅里叶变换获得相应的频率-多普勒2维平面。然后,利用2维映射处理,将超宽带信号映射为窄带信号,实现多普勒域能量的聚焦。最后,根据映射后的窄带信号对应的多普勒频率获得目标径向速度。该方法不但有效地解决了超宽带雷达多普勒色散对测速的影响,而且规避了由于目标沿距离维的走动引起的慢时间域不能有效的能量积累。通过速度估计值,进行运动补偿后可获得目标距离像。此外,根据相关条件,进一步推导了速度适应范围。仿真实验结果验证了该方法的有效性。

Two-Dimensional （2D） projection in temporal-Doppler plan is utilized to solve the effects of range-Doppler coupling and Doppler dispersion on radial velocity estimation for Linear Frequency Modulation （LFM） Ultra-WideBand （UWB） radar. First, temporal-Doppler 2D plane is got via 2D Fourier transform in fast-slow time domain. Second, 2D projection is performed to obtain energy focusing in UWB Doppler domain through mapping the UWB signal into narrow signal. Finally, radial velocities of moving targets are obtained according to the Doppler frequencies of the narrow signal after the mapping. This method not only solves the negative impacts of UWB radar Doppler dispersion on velocity estimation, but also voids that energy can not be accumulated in slow time since targets move along range resolution bins. Range profile of targets can also be got via the corresponding compensation with the estimated velocities. Besides, the velocity restriction is further derived according to the corresponding requirements. The simulation results illustrate the effectiveness of this method.