基于多层快速多极子算法的快速成像方法研究

Research on Fast Imaging Method Based on Multi-layer Fast Multipole Algorithm

多层快速多极子算法(MLFMA)能够快速准确地实现三维复杂目标的电磁散射计算。本文利用MLFMA对三维复杂目标进行几何分层分组,通过求解混合场积分方程(CFIE)获得给定频率和观测方向的雷达散射截面(RCS);然后利用每个子区域内的电流对散射场贡献大小,即可实现高分辨率雷达目标三维成像。论文对实现二维成像的相干投影和非相干投影技术开展了有效性验证。与传统的ISAR成像方法相比,基于MLFMA的快速成像方法所需的成像数据计算成本极低,所成图像更加直观,且可多角度呈现目标散射特性。

MLFMA can quickly and accurately calculate the electromagnetic scattering of 3 d complex targets.In this paper,MLFMA is used to group 3 d complex targets geometrically,and the radar cross section(RCS)of a given frequency and observation direction is obtained by solving the mixed field integral equation(CFIE).Then the contribution of the current in each sub-region to the scattering field can be used to achieve the three-dimensional imaging of the high-resolution radar target.In this paper,the coherence projection and incoherence projection techniques for two-dimensional imaging are validated.Compared with the traditional ISAR imaging method,the fast imaging method based on MLFMA requires very low calculation cost of imaging data,and the resulting image is more intuitive and can present the scattering characteristics of the target from multiple angles.