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电特大复杂目标电磁特性的高效精确并行计算 总被引:2,自引:0,他引:2
在不同层间采用不同的并行方式来处理多层快速多极子中的平面波和转移矩阵后,并行算法的效率非常高.但当目标尺寸达到几百个电波长时,计算多极子中盒子的距离信息非常消耗计算资源,成为进一步提升并行多层快速多极子仿真能力的瓶颈.为此,提出了一种并行的递归相邻中心算法来高效处理盒子间距离信息.通过计算超过2,300万个未知数模拟的直径达到200个波长金属球的散射,检验了本文并行算法的精度和效率,充分说明本文方案消除了上述瓶颈极大提高了并行算法的仿真能力.为进一步证明算法的通用和高效,还计算了尺寸接近500个电波长的飞机模型电磁特性,这是目前国际上公开报道的用MLFMA所能求解的尺寸最大的问题. 相似文献
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针对曲面共形阵列结构电磁散射特性的高效、精确仿真分析需求,提出了一种并行综合函数矩量法处理方案.该方法是传统电磁经典数值算法——矩量法的一种改进形式,通过几何区域分解处理和综合基函数的方式极大降低了算法的内存消耗,使得单机分析电大尺寸问题和大规模阵列问题成为可能.更为重要的是,针对周期阵列结构,该方法具备综合函数复用特性和多区域并行处理特性,能够大大提高算法的综合处理效率.一个6×11的柱面共形贴片阵列被用于验证所提方法的性能,仿真结果表明,对于周期阵列结构,该方法的计算精度与多层快速多极子算法相当,虽然计算效率略低于多层快速多极子方法,但内存消耗比多层快速多极子方法低一个数量级. 相似文献
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基于高性能计算的电磁数值模拟在目标电磁散射特性分析中发挥着越来越重要的作用.由于任一种数值方法都有一定的适用范围,不能高效处理所有问题,因此,有必要发展和集成多种数值方法,形成能够为不同类型问题的雷达散射截面(radar cross section,RCS)计算提供高效解决途径的软件系统.文中在并行自适应结构/非结构网格应用支撑软件框架之上,充分考虑数值方法的可扩展性以及物理个性的可分离性,通过基于机理、数据的混合可计算建模和接口设计,以及算法的模块化开发,发展了多种用于RCS计算的数值方法,并将其集成到高性能电磁数值模拟软件系统JEMS中.数值算例表明了JEMS具有高效分析多种目标电磁散射特性的能力,并在大规模并行计算方面具有显著优势. 相似文献
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虽然快速多极子算法FMM(Fast Multipole Method)和多层快速多极子算法MLFMA(Multi-Level Fast Multipole Algorithm)是解决复杂目标电磁散射问题比较有效的方法,但是当问题的规模较大时,传统的串行FMM 和MLFMA难以胜任.本文在工作站网络系统NOW(Network Of Workstation)上采用并行处理技术来解决电大尺寸复杂目标电磁散射问题.结果表明:本文提出的并行解决方案与国内外相关成果相比不仅更具实用性,并行效率达到54%以上,且解决了串行方法难以解决的电磁散射问题,本文在四台DEC工作站构成的NOW系统上用32小时完成了未知量为160,000的雷达散射截面的计算. 相似文献
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针对主动雷达导引头对防空导弹武器系统制导雷达站检测与识别的需求,研究了平面隙缝阵列天线的宽带电磁散射特性.将天线的电磁散射机理与目标高频散射中心理论相结合,建立了天线的电磁散射模型,分别采用矩量法和物理光学法计算天线的模式项散射场和结构项散射场,并从理论上证明了天线散射中心的客观存在,分析了隙缝阵列天线的散射中心分布特征.最后对不同视角下天线的高分辨距离像进行了仿真,为进一步理解天线的电磁散射机理、分析其宽带电磁散射特性、以及采用高分辨率成像技术对雷达站进行检测与识别奠定了基础. 相似文献
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采用混合位积分方程(MPIE)和基于RWG基函数的矩量法分析计算了埋地三维目标的近场电磁散射问题,利用二级离散复镜像(DCIM)和广义函数束(GPOF)相结合的方法求解近场Sommerfeld积分,很好地解决了多层媒质中电磁散射计算中的棘手问题,其方法简练、精确、高效,数值分析结果与有关文献吻合很好,证实了该方法的正确性和通用性。此外,该文还通过计算比较了不同观察点、不同目标埋地深度及不同地层媒质参数的电磁散射特性。 相似文献
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着重讨论半空间FDTD并行计算方法,入射源的特殊处理方式,和如何调节负载不平衡三个问题,给出一种简单易行的地下目标雷达散射截面的并行时域有限差分(FDTD)方案,并在北京理工大学电磁仿真中心刘徽并行计算平台上,做了具体的程序实现和数值实验,实验不仅证实了算法的精度,而且还表明并行方案的高效,即当参与计算的处理器数量达到14个时,并行效率仍然可以保持在80%以上.在此基础上,用开发的程序计算了以往串行算法无法计算的电大地下典型目标的雷达散射截面. 相似文献
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位积分方程组的主要特点是以电磁位为未知函数,这些未知函数在具有不同电磁参数的介质分界面处是连续的,因而在矩量法的实现过程中能够非常方便地应用高阶插值基函数来展开未知函数,以便获得高精度的解。但是,经典的点匹配方案使该模型的数值稳定性较差。本文用位积分方程组矩量法模型计算任意截面非均匀介质柱的电磁散射,采用三角形离散方案和高阶插值基函数,在测试过程中应用新提出的测试方法,克服了原位方程组矩量法模型的数值不稳定性。对矩量法矩阵中自阻抗元素的奇异性处理方法也作了详细介绍。文中提供的数值结果表明,该方法是精确、稳定的。 相似文献
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Green's function refinement as an approach to radar backscatter:general theory and applications to LGA scattering from the ocean 总被引:3,自引:0,他引:3
We present a new approach to the computation of radar returns from dielectric bodies whose boundary is the deformation of a plane surface. The method relies on combining a systematic improvement in the Green's function with a good approximate choice of local boundary condition. In this paper, the general theory is presented together with a simple application where the Green's function is that for a lossy dielectric half-space. We derive the root radar cross section (RCS) for a statistical surface and the mean backscatter RCS for a rough surface. We explore the applications to low-grazing-angle (LGA) scattering from statistical surfaces with an ocean-like spectrum and demonstrate that such a model explains some of the previously unexplained LGA phenomena, such as the absolute and relative levels of the vertical (VV) and horizontal (HH) channel RCS measurements 相似文献
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地下目标散射的FDTD计算 总被引:1,自引:0,他引:1
该文给出了一种利用时域有限差分法(FDTD),结合各向异性完全匹配层(UPML)以及互易原理,计算地下目标雷达散射截面的计算方法。通过数值实验,对这种计算方法的数值性能作了仔细研究。给出了一批新的不同电尺寸、不同形状、不同介电常数地下目标的雷达散射截面计算结果。 相似文献
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An innovative approach to computing the high-frequency radar cross sections (RCSs) of complex radar targets in real time, using a 3-D graphics workstation, is presented. The target (typically, an aircraft) is modeled with the I-IDEAS solid-modeling software, using a parametric-surface approach. The high-frequency RCS is obtained through physical optics (PO), the method of equivalent currents (MEC), the physical theory of diffraction (PTD), and the impedance boundary condition (IBC) techniques. The CPU time for the RCS prediction is spent only on the electromagnetic part of the computation, while the more time-consuming geometric-model manipulations are left to the graphics hardware 相似文献
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High-frequency RCS of complex radar targets in real-time 总被引:31,自引:0,他引:31
This paper presents a new and original approach for computing the high-frequency radar cross section (RCS) of complex radar targets in real time with a 3-D graphics workstation. The aircraft is modeled with I-DEAS solid modeling software using a parametric surface approach. High-frequency RCS is obtained through physical optics (PO), method of equivalent currents (MEC), physical theory of diffraction (PTD), and impedance boundary condition (IBC). This method is based on a new and original implementation of high-frequency techniques which the authors have called graphical electromagnetic computing (GRECO). A graphical processing approach of an image of the target at the workstation screen is used to identify the surfaces of the target visible from the radar viewpoint and obtain the unit normal at each point. High-frequency approximations to RCS prediction are then easily computed from the knowledge of the unit normal at the illuminated surfaces of the target. The image of the target at the workstation screen (to be processed by GRECO) can be potentially obtained in real time from the I-DEAS geometric model using the 3-D graphics hardware accelerator of the workstation. Therefore, CPU time for RCS prediction is spent only on the electromagnetic part of the computation, while the more time-consuming geometric model manipulations are left to the graphics hardware. This hybrid graphic-electromagnetic computing (GRECO) results in real-time RCS prediction for complex radar targets 相似文献
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《Microwave Theory and Techniques》2006,54(9):3594-3601
A scale changing approach is proposed for the electromagnetic modeling of phase-shifter elements used in reconfigurable microelectromechanical system (MEMS)-controlled reflectarrays. Based on the partition of the discontinuity plane in planar sub-domains with various scale levels, this technique allows the computation of the phase shift from the simple cascade of networks, each network describing the electromagnetic coupling between two scale levels. The high flexibility of the approach associated with the advantages of the integral equations formulations renders this original approach powerful and rapid. The scale-changing technique allows quasi-instantaneous computing of the 1024 phase shifts achieved by ten RF-MEMS switches distributed on the phase-shifter surface. Moreover, the proposed approach is much better than the finite-element-method-based software in time costing. Experimental data are given for validation purposes. 相似文献