一种进动锥体目标的EM参数估计方法

为分离进动锥体散射点回波、反演锥体的尺寸和进动角等参数,提出了一种EM算法分离散射点微多普勒并进行微动参数估计的方法.该方法由进动锥体回波的类正弦调频模型,经过时频平面检测后,采用EM算法迭代地估计多分量正弦信号的参数和分离散射点的时频观测值,在此基础上再进行锥底散射点多普勒半周期叠加、估计锥体目标尺寸和微动参数.仿真结果表明,在弱散射点信噪比大于2 dB时,可估计出目标的尺寸和进动角等参数,从而验证了该方法的有效性.

An EM parameter estimation algorithm for precession cone targets

To separate the scattering point echoes of precession cone target and estimate the parameters such as its size,precession angle,etc.,this paper proposes an expectation maximization(EM)algorithm to separate the scattering point micro-Doppler and estimate the micro-motion parameters.In this method,modeling the apex’s micro-Doppler as sine frequency modulation(SFM)and detecting the signals on time-frequency transform plane,EM algorithm is used to iteratively estimate the parameters of multi-component sinusoidal signal and the time-frequency observation values of scattered points,on the basis of which to perform Doppler half-period superposition of scattering points at the cone bottom,and to estimate the cone’s size,micro-motion parameters.The simulation results show that when the SNR of the weak scattering point is greater than 2 dB,the parameters as size,precession angle of the target,etc.,can be estimated,thus verifying the effectiveness of the proposed method.