为衰减地质雷达数值模拟时因截断区域厚度或者参数影响产生的倏逝波,提出了一种利用复频移完美匹配层(complex frequency shifted perfectly matched layer,CFS-PML)作为吸收边界,并结合频域高阶有限元算法(higher order finite element...为衰减地质雷达数值模拟时因截断区域厚度或者参数影响产生的倏逝波,提出了一种利用复频移完美匹配层(complex frequency shifted perfectly matched layer,CFS-PML)作为吸收边界,并结合频域高阶有限元算法(higher order finite element method,HO-FEM)求解电磁总场分量分布情况的新方法.该方法改善了截断域介质本构张量矩阵的特性,利用矩阵频移参量α吸收倏逝波,提高掠射角处吸收性能.数值实验结果表明,与传统PML相比,结合CFS-PML的HO-FEM方法精度得到明显提高,反射误差额外降低10~30 dB,节省了17%~30%的计算时间.此外,该方法能应用于复杂地质结构模型的电磁总场计算,为地质雷达数值模拟提供了一种新的方法.展开更多
To study bistatic scattering from a target at low altitude above two- dimensional (2D) randomly rough sea surface under an electromagnetic (EM) wave incidence at low grazing angle (LGA), a numerical approach of the fi...To study bistatic scattering from a target at low altitude above two- dimensional (2D) randomly rough sea surface under an electromagnetic (EM) wave incidence at low grazing angle (LGA), a numerical approach of the finite element method (FEM) is developed. The conformal perfectly matched layer (PML), as the truncation boundary of the FEM, is employed to reduce the reflection error of planar PML in conventional FEM. Numerical code of our FEM is examined by available solution of the forward backward iterative (FBM) method. Bistatic and back-scattering from composite model of a target above random rough sea surface generated by Monte Carlo realization, and functional dependence upon the sea surface wind speed, target altitude, incident and scattering angles, etc. are numerically simulated and discussed. This paper presents a numerical description of the observation principle and physical insight associated with the coupling interactions of a complex volumetric target and random rough sea surface.展开更多
文摘为衰减地质雷达数值模拟时因截断区域厚度或者参数影响产生的倏逝波,提出了一种利用复频移完美匹配层(complex frequency shifted perfectly matched layer,CFS-PML)作为吸收边界,并结合频域高阶有限元算法(higher order finite element method,HO-FEM)求解电磁总场分量分布情况的新方法.该方法改善了截断域介质本构张量矩阵的特性,利用矩阵频移参量α吸收倏逝波,提高掠射角处吸收性能.数值实验结果表明,与传统PML相比,结合CFS-PML的HO-FEM方法精度得到明显提高,反射误差额外降低10~30 dB,节省了17%~30%的计算时间.此外,该方法能应用于复杂地质结构模型的电磁总场计算,为地质雷达数值模拟提供了一种新的方法.
基金the China State Key Basic Research Project (Grant No. 2001CB309401-05)the National Natural Science Foundation of China (Grant No. 60171009).
文摘To study bistatic scattering from a target at low altitude above two- dimensional (2D) randomly rough sea surface under an electromagnetic (EM) wave incidence at low grazing angle (LGA), a numerical approach of the finite element method (FEM) is developed. The conformal perfectly matched layer (PML), as the truncation boundary of the FEM, is employed to reduce the reflection error of planar PML in conventional FEM. Numerical code of our FEM is examined by available solution of the forward backward iterative (FBM) method. Bistatic and back-scattering from composite model of a target above random rough sea surface generated by Monte Carlo realization, and functional dependence upon the sea surface wind speed, target altitude, incident and scattering angles, etc. are numerically simulated and discussed. This paper presents a numerical description of the observation principle and physical insight associated with the coupling interactions of a complex volumetric target and random rough sea surface.
