基于高阶边界散射变换的二面角快速成像算法

Fast imaging algorithm of dihedral based on high-order boundary scattering transform

基于二面角的单站圆周扫描模型,本文分析了不同张角二面角的奇次反射回波分布规律.通过建立正向散射模型并求解在各观测角度下对散射场贡献最大的出射点,证明了在二面角内的各种散射中,镜面反射起主导作用.基于此,本文只考虑镜面反射对散射场的贡献,建立了出射边驻定相位点与回波波前之间的一一对应关系,提出了一种高阶边界散射变换(high-order boundary scattering transform,HBST)算法,有效消除了由多次反射带来的成像伪影.相较传统的后向投影算法,本文提出的HBST算法在计算量和成像效率上都有显著的提升,仿真和实验结果验证了算法的有效性.

In this paper,based on the monostatic cylindrical scanning model of the dihedral,we analyze the distribution pattern of odd reflection echoes from dihedrals with different opening angles.By establishing a forward scattering model and determining the exit points that contribute the most to the scattering field at each observation angle,we demonstrate that among various scattering mechanisms within the dihedral angle,specular reflection plays a dominant role.Accordingly,this study focuses solely on the contribution of specular reflection to the scattering field and establishes a one-to-one correspondence between the exit points with stationary phase and the wavefront of the echoes.A high-order boundary scattering transform(HBST)algorithm is proposed to effectively eliminate imaging artifacts caused by multiple reflections.Compared to traditional back-projection algorithms,the HBST algorithm shows significant improvements in computational efficiency and imaging effectiveness.Simulation and experimental results validate the effectiveness of the algorithm.