弹道类目标进动周期特征提取方法研究

A Study on Precession Period Extraction Method of Ballistic Targets

提出一种自相关(AUTOC)法与平均幅度差函数(AMDF)法相结合的弹道类目标进动周期提取方法(PreAUTOC-AMDF法)。该方法先对目标的雷达散射截面积时间序列进行预处理(低通滤波或平滑),再将AUTOC法的周期提取函数与AMDF法的周期提取函数的倒数相乘,以突显新构造的周期提取函数的极值点。把相邻两个极值点的时间间隔作为进动的估计周期。文中从参数估计的角度分析了目标进动周期提取方法的克拉美罗界,并将PreAUTOC-AMDF法与其他周期提取方法进行了性能比较。理论分析与计算机仿真结果表明,PreAUTOC-AMDF法的均方误差最接近克拉美罗界,具有更高的周期提取精度,是真假弹头识别应用中一种有潜力的目标进动周期提取方法。

In this paper, a new method, namely PreAUTOC-AMDF method to extract precession period is proposed, which combines autocorrelation method（AUTOC） and average magnitude difference function method（AMDF）. In this new method, we perform preprocessing of RCS sequences with a low pass filter or smoothing. Then we multiply AUTOC with the reciprocal of AMDF, which makes the extremum of new extracting function more visible, then the interval of two extrema is taken as estimated precession period. In terms of parameter estimation, the Cramer-Rao bound is analyzed, and the mean square error of the new method is compared with it. Theoretical analysis and computer simulation show that the new method has higher precision than other methods. Above all, the new method proposed in this paper is a potential method for precession period extraction.