提出一种基于高分辨距离像的混合EM算法用于自动目标识别,采用混合Gamma分布对目标主要散射点的特征进行建模。混合Gamma分布的参数分为两类:1)可以通过EM算法进行更新Gamma分布的混合系数和尺度参数;2)不存在解析更新表达式的Gamma分布的形状参数。提出的算法可为两部分:1)原始EM算法的加速算法;2)利用共轭梯度法估计Gamma分布的形状参数,并对更新表达式进行推导。数值仿真结果验证了提出方法的有效性。

For automatic target recognition, a mixed EM algorithm based on high resolution range profile (HRRP) is proposed. Mixed Gamma distribution is used to model the characteristics of the target's primary scattering point. The parameters of the mixed Gamma distribution are divided into two categories: 1) Mixed coefficient and scale parameters, which can be updated by EM algorithm. 2) Shape parameters, the analytic updating expression of which does not exist. Therefore, we present a two-step algorithm: first, the original EM algorithm is accelerated; second, the shape parameters of the Gamma distribution are estimated by a conjugate gradient method, and the updating expression is derived. The empirical studies show the efficiency and effectiveness of our method.

TN957. 51