弹道中段群目标平动补偿与分离方法

Translation Compensation and Resolution of Multi-ballistic Targets in Midcourse

弹道微动群目标时频图是多目标多散射点微多普勒的叠加,以往针对单目标的补偿与分离方法不再适用。针对这一问题,该文首先分析了群目标及诱饵的微多普勒形式;利用弹道中段目标运动平稳,短时观测加速度近似为常数的特性,采用Radon变换检测微多普勒曲线的倾斜程度,用最小熵准则和高斯函数拟合的方法估计平动参数,进而完成平动补偿;对补偿后的群目标时频图利用Viterbi算法提取各条微多普勒曲线,依据同一目标各散射点微多普勒的周期相关性,完成群目标分离;最后仿真验证了以上方法的有效性。

Time-frequency image of multi-ballistic targets is composed of micro-Doppler of multi-targets with multi-scattering centers, which makes the methods for single target invalid. Firstly, micro-Doppler of precessing missile and swinging decoy is analyzed. Considering midcourse ballistic targets＇ characteristics that the motion is stable and the acceleration is approximately a constant in short time, Radon transform is applied to the detection of linear degree of the micro-Doppler, then motional parameters are estimated based on minimum entropy criteria and Gauss fitting. After compensating translation, Viterbi algorithm is used to extract micro-Doppler from the time-frequency image, with which multi-targets can be resolved according to the principle that scattering centers on one target are with the same micro-Doppler cycles, but those on different targets are not. Finally, Simulations verify the effectiveness of the proposed method.