The unsplit convolutional perfectly matched layer absorption performance analysis of evanescent wave in GPR FDTD forward modeling
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摘要: 介绍了CPML边界条件的原理,推导了CPML的GPR正演FDTD差分公式,对比分析了Berenger PML、UPML、CPML三种PML对倏逝波的吸收性能.开展了PML边界中关键参数κ和α的选取实验,确定了参数的取值范围与选取原则.然后,以二维TM波为例,研究了倏逝波产生的机理,分析了决定逝波性吸收性能的影响因素.均匀介质的波场快照、检测点的反射误差及全局反射误差对比,说明了3种边界条件对传输波都具有较好的吸收能力,而对低频倏逝波的吸收表现迥异,其中CPML因为引入了参数α,对倏逝波的吸收效果最佳,但离散化造成的全域误差也最大.最后,应用加载UPML和CPML边界条件的FDTD程序,开展了GPR二维剖面法、宽角法矩状地电模型及三维复杂模型的正演,展示了倏逝波反射对雷达正演剖面及波场快照的影响.进一步对比了UPML与CPML对倏逝波的吸收表现优劣,结果显示,CPML可有效减少边界反射误差,并能取得满意的精度,综合考虑对倏逝波的吸收、全域误差、编程难易程度等因素,在GPR正演中推荐使用CPML.
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关键词:
- 探地雷达 /
- 不分裂卷积完全匹配层 /
- 单轴各向异性完全匹配层 /
- 倏逝波 /
- 时域有限差分法
Abstract: This article introduces the principle of CPML boundary conditions, and deduces its FDTD formula for GPR forward modeling, and then compares and analyzes the absorption properties of evanescent wave in Berenger PML, UPML, CPML. The numerical experiment of key parameters κ and α in PML were performed so as to determine its range and selection principles. Then, using the two-dimensional TM wave as an example, we studied the mechanism of evanescent wave generation and the influence factors of absorption properties. Wavefield snapshot of uniform medium, reflection error at detection point and global reflection error comparison shows that the three kinds of PML have fabulous absorption capacity to travelling-wave, but quite different to evanescent wave, especially in the low-frequency. Because the parameter α was introduced, the absorption of evanescent wave in CPML is exceptionally excellent; however, the global error is the largest caused by discretization. Finally, we used the FDTD program with UPML and CPML boundary conditions to carry out 2D GPR forward modeling using profile method and wide-angle method on rectangular geoelectric model and 3D uniform medium model. From the experiment, we observed that there is a huge influence of evanescent wave on both the radar forward modeling profile and wavefield snapshot. Furthermore, taking the absorption performance of evanescent wave by UPML and CPML into consideration, we can determine that CPML can effectively reduce the reflection error in truncation boundary, and obtain a satisfying accuracy. Considering the absorption performance of evanescent wave, the global error, programming difficulty and other factors, in the GPR forward modeling, we highly recommend the use of CPML boundary condition in GPR studies. -
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[1] Berenger J P. 1994. A perfectly matched layer for the absorption of electromagnetic waves. Journal of Computational Physics, 114(2): 185-200.
[2] Berenger J P. 1996. Perfectly matched layer for the FDTD solution of wave-structure interaction problems. IEEE Transactions on Antennas and Propagation, 44(1): 110-117.
[3] Berenger J P. 1997. Numerical reflection of evanescent waves from perfectly matched layers. IEEE Antennas and Propagation Society International Symposium, Montreal, Canada, July, (2): 1888-1891.
[4] Berenger J P. 1998.An effective PML for the absorption of evanescent waves in waveguides.IEEE Microwave and Guided Wave Letters, 8(5): 188-190.
[5] Berenger J P. 1999. Evanescent waves in PML's: Origin of the numerical reflection in wave-structure interaction problems. IEEE Trans. Antennas Propag, 47(10): 1497-1503.
[6] Berenger J P. 2000. Numerical reflection of evanescent waves by PMLs: Origin and interpretation in the FDTD case. Expected consequences to other finite methods.Int.J.Numer. Model, 13(2): 2-3.
[7] Berenger J P. 2002. Numerical reflection from FDTD-PMLs: a comparison of the split PML with the unsplit and CFS PMLs. IEEE Transactions on Antennas and Propagation, 50(3): 258-265.
[8] Berenger J P. 2002. Application of the CFS PML to the absorption of evanescent waves in wave guides.IEEE Microwave and Wireless Components Letters, 12(6): 218-220.
[9] Cassidy N J, Millington T M. 2009. The application of finite-difference time-domain modelling for the assessment of GPR in magnetically lossy materials. Journal of Applied Geophysics, 67(4): 296-308.
[10] Di Q Y, Wang M Y.1999. 2D finite element modeling for radar wave. Chinese J. Geophys. (in Chinese), 42(6): 818-825.
[11] Dimitri K,Roland M. 2007. An unsplit convolutional perfectly matched layer improved at grazing incidence for the seismic wave equation. Geophysics, 72(5): 255-167.
[12] Drossaert F H,Giannopoulos A. 2007. A nonsplit complex frequency-shifted PML based on recursive integration for FDTD modeling of elastic waves. Geophysics, 72(2): 9-17.
[13] Drossaert F H,Giannopoulos A. 2007. Complex frequency shifted convolution PML for FDTD modeling of elastic waves. Wave Motion, 44: 593-604.
[14] Engquist B, Majda A. 1977. Absorbing boundary conditions for the numerical simulation of waves.Math.Comput., 31(139): 629-651.
[15] Fang H Y, Lin G. 2013.Simulation of GPR wave propagation in complicated geoelectric model using symplectic method. Chinese J. Geophys.(in Chinese), 56(2): 653-659.
[16] Fang H Y, Lin G. 2012.Symplectic partitioned Runge-Kutta methods for two-dimensional numerical model of ground penetrating radar.Computers & Geosciences, 49: 323-329.
[17] Feng D S, Chen C S, Dai Q W. 2010. GPR numerical simulation of full wave field based on UPML boundary condition of ADI-FDTD.Chinese J. Geophys. (in Chinese), 53(10): 2484-2496.
[18] Feng D S, Chen C S, Wang H H.2012. Finite element method GPR forward simulation based on mixed boundary condition. Chinese J. Geophys.(in Chinese), 55(11): 3774-3785.
[19] Feng D S,Xie Y. 2011. Three dimensional GPR numerical simulation of full wave field based on UPML boundary condition of ADI-FDTD radar.Journal of Central South University: Science and Technology, 42(8): 2363-2372.
[20] Feng D S, Chen J W, Wu Q. 2014. A hybrid ADI-FDTD subgridding scheme for efficient GPR simulation of dispersion media.Chinese J. Geophys. (in Chinese), 57(4): 1322-1334.
[21] Giannopoulos A. 2005. Modelling ground penetrating radar by GprMax. Construction and Building Materials, 19(10): 755-762.
[22] Gedney S D. 1996. An anisotropic perfectly matched layer-absorbing medium for the truncation of FDTD lattices.IEEE Transactions on Antennas and Propagation,44 (12): 1630-1639.
[23] Gedney S D. 1996. An Anisotropic PML absorbing media for the FDTD simulation of fields in lossy and dispersive media.Electromagnetics, 16(4): 399-415.
[24] Ge D B,Yan Y B. 2005. Finitedifference Time Domain Method for Electromagnetic Waves(in Chinese). Xi'an:Xidian University Press.
[25] Giannopoulos A. 2008. An improved new implementation of complex frequency shifted PML for the FDTD method. IEEE Transactions on Antennas and Propagation, 56(9): 2995-3000.
[26] Irving J, Knight R. 2006. Numerical modeling of ground-penetrating radar in 2-D using MATLAB.Computers & Geosciences, 32(9): 1247-1258.
[27] Katz D S,Thiele E T,Taflove A. 1994. Validation and extension to three dimensions of the Berenger PML absorbing boundary condition for FD-TD meshes. IEEE Microwave and Guided Wave Letters, 4(8): 268-270.
[28] Kuzuoglu M, Mittra R. 1996. Frequency dependence of the constitutive parameters of causal perfectly matched anisotropic absorbers. IEEE Microwave and Guided Wave Letters, 6(12): 447-449.
[29] Liao Z P, Wong H L, Yang B P, et al. 1984.A transmitting boundary for transient wave analysis.Scientia Sinica (Series A),27(10): 1063-1076.
[30] Li J, Zeng Z F, Huang L, Liu F S. 2012. GPR simulation based on complex frequency shifted recursive integration PML boundary of 3D high order FDTD. Computers & Geosciences, 49:121-130.
[31] Li J, Zeng Z F, Wu F S, et al. 2010.Study of three dimension high order FDTD simulation of GPR.Chinese J.Geophys.(inChinese), 53(4):974-981.
[32] Li J X. 2007. Research on algorithms for implementing perfectly matched layers in the finite difference time domain method [Doctor's thesis]. School of Electronic Information Engineering, Tianjin university.
[33] Li Z H, Huang Q H, Wang Y B. 2009. A 3-D staggered grid PSTD method for borehole radar simulations in dispersive media. Chinese J. Geophys. (in Chinese),52(7): 1915-1922.
[34] Li Z H, Huang Q H. 2014. Application of the complex frequency shifted perfectly matched layer absorbing boundary conditions in transient electromagnetic method modeling. Chinese J. Geophys. (in Chinese), 57(4): 1292-1299.
[35] Martin R, Komatitsch D, Gedney S D, et al. 2010. A high-order time and space formulation of the unsplit perfectly matched layer for the seismic wave equation using auxiliary differential equations (ADE-PML). CMES, 56(1): 17-40.
[36] Mei K K, Fang J. 1992. Superabsorption-a method to improve absorbing boundary conditons. IEEE Trans. on Antennas and Propagation, 40:1001-1010.
[37] Mur G. 1981.Absorbing boundary conditions for the finite-difference approximation of the time-domain electromagnetic field equations. IEEE Trans. Electomagn Compat, EMC-23(4): 377-382.
[38] Moerloose J D,Stuchly M. 1995. Behavior of Berenger's ABC for evanescent waves. IEEE Microwave and Guided Wave Letters, 5(10): 344-346.
[39] Roden J, Gedney S D. 2000. Convolution PML (CPML): an efficient FDTD implementation of the CFS-PML for arbitrary media. Microwave and optical technology letters, 27: 334-339.
[40] Sacks Z S, Kingsland D M, Lee R, et al. 1995. A perfectly matched anisotropic absorber for use as an absorbing boundary condition. IEEE Transactions onAntennas and Propagation,43 (8): 1460-1463.
[41] Taflove A, Brodwin M E. 1975. Numerieal solution of steady-state EM scattering Problems using the time-dependent Maxwell's equations.IEEE Trans. MicrowaveTheory Tech, 23: 623-630.
[42] Wang L N, Liang C H. 2006. A new implementation of CFS-PML for ADI-FDTD method.Microwave and Optical Technology Letters, 48(10): 1924-1928.
[43] Xu T, McMechan G A. 1997. GPR attenuation and its numerical simulation in 2.5 dimensions.Geophysics, 62: 403-414.
[44] Zeng Z F, Liu S X, Feng X. 2010.Theory and Application of Ground Penetrating Radar(in Chinese), Beijing: Electronic Industry Press.
[45] Zhang L X, Fu LY, Pei Z L. 2010. Finite difference modeling of Biot's poroelastic equations with unsplit convolutional PML and rotated staggered grid.Chinese J. Geophys. (in Chinese),53(10): 2470-2483.
[46] Zhang W, Shen Y. 2010. Unsplit complex frequency-shifted PML implementation using auxiliary differential equations for seismic wave modeling.Geophysics, 75(4): 141-154.
[47] Zhang X W, Han L G, Huang L, et al. 2009. A staggered-grid high-order difference method of complex frequency-shifted PML based on recursive integration for elastic wave equation.Chinese J. Geophys. (in Chinese),52(7): 1800-1807.
[48] Zhan Y L, Chang Y J, Cao Z L. 2008. Modeling of groundpenetrating radar based on UPML boundary conditions.Resources Environment and Engineering, 22(2): 235-238.
[49] 底青云,王妙月. 1999. 雷达波有限元仿真模拟. 地球物理学报,42(6):818-825.
[50] 方宏远,林皋. 2013. 基于辛算法模拟探地雷达在复杂地电模型中的传播.地球物理学报,56(2):653-659.
[51] 冯德山,陈佳维,吴奇. 2014. 混合ADI-FDTD亚网格技术在探地雷达频散媒质中的高效正演.地球物理学报,57(4):1322-1334.
[52] 冯德山,陈承申,戴前伟. 2010.基于UPML边界条件的交替方向隐式有限差分法GPR全波场数值模拟. 地球物理学报,53(10):2484-2496.
[53] 冯德山,陈承申,王洪华. 2012. 基于混合边界条件的有限单元法正演模拟. 地球物理学报,55(11): 3774?3785.
[54] 冯德山,谢源. 2011. 基于单轴各向异性完全匹配层边界条件的ADI-FDTD三维GPR全波场正演. 中南大学学报(自然科学版),42(8):2363-2372.
[55] 葛德彪,闫玉波. 2005. 电磁波时域有限差分法. 西安:西安电子科技大学出版社,67-81.
[56] 李建雄. 2007.时域有限差分法中完全匹配层的实现算法研究[博士论文]. 天津:天津大学电子信息工程学院.
[57] 李静,曾昭发,吴丰收等. 2010. 探地雷达三维高阶时域有限差分法模拟研究.地球物理学报,53(4):974- 981.
[58] 李展辉,黄清华,王彦宾. 2009. 三维错格时域伪谱法在频散介质井中雷达模拟中的应用.地球物理学报,52(7):1915-1922.
[59] 李展辉,黄清华. 2014.复频率参数完全匹配层吸收边界在瞬变电磁法正演中的应用. 地球物理学报,57(4):1292-1299.
[60] 曾昭发,刘四新,冯晅. 2010.探地雷达原理与应用. 北京:电子工业出版社.
[61] 张鲁新,符力耘,裴正林. 2010. 不分裂卷积完全匹配层与旋转交错网格有限差分在孔隙弹性介质模拟中的应用. 地球物理学报,53(10):2470-2483.
[62] 张显文,韩立国,黄玲等. 2009.基于递归积分的复频移PML弹性波方程交错网格高阶差分法. 地球物理学报,52(7):1800-1807.
[63] 詹应林,昌彦君,曹中林.2008. 基于UPML 吸收边界的探地雷达数值模拟研究.资源环境与工程,22(2):235-238.
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