Adaptive finite element for 3D time-domain airborne electromagnetic modeling based on hybrid posterior error estimation

Airborne electromagnetic (AEM) forward modeling has been extensively developed in past years. However, not much attention has been paid to the adaptive numerical algorithms for time-domain EM modeling. We create an adaptive method that can generate an effective mesh for time-domain 3D airborne EM full-wave modeling using unstructured finite-element method and backward Euler scheme. For the estimation of the posterior error in the adaptive process, we use a hybrid technique based on the continuity of the normal current density for modeling the off-time channels, and on the continuity of the tangential magnetic field for the on-time channels. To improve the stability of the forward modeling and control the number of grids in the adaptive process, a random grid selection technique is applied. We check the modeling accuracy of the algorithm by comparing our adaptive results with the semi-analytical solution for a time-domain AEM system over a homogeneous half-space. Further we test the effectiveness of our al...

[1]  Michael Commer,et al.  A parallel finite-difference approach for 3D transient electromagnetic modeling with galvanic sources , 2004 .

[2]  3D finite-difference modeling of time-domain electromagnetic data for mineral exploration , 2011 .

[3]  Daniel A. White,et al.  An efficient vector finite element method for nonlinear electromagnetic modeling , 2007, J. Comput. Phys..

[4]  Marc A. Vallée,et al.  Application of Occam's inversion to airborne time-domain electromagnetics , 2009 .

[5]  G. W. Hohmann,et al.  A finite-difference, time-domain solution for three-dimensional electromagnetic modeling , 1993 .

[6]  M. Best,et al.  Airborne Electromagnetic Mapping for Buried Quaternary Sands and Gravels in Northeast British Columbia, Canada , 2006 .

[7]  T. Kolev,et al.  Large-scale 3D geoelectromagnetic modeling using parallel adaptive high-order finite element method , 2015 .

[8]  Bo Zhang,et al.  A goal-oriented adaptive finite-element method for 3D scattered airborne electromagnetic method modeling , 2016 .

[9]  Jing Cai,et al.  3D time-domain airborne EM forward modeling with topography , 2016 .

[10]  John L. Volakis,et al.  Finite Element Method Electromagnetics , 1998 .

[11]  C. H. Stoyer,et al.  Finite-difference calculations of the transient field of an axially symmetric Earth for vertical magnetic dipole excitation , 1983 .

[12]  Yin Chang,et al.  The full-time electromagnetic modeling for time-domain airborne electromagnetic systems , 2013 .

[13]  Misac N. Nabighian,et al.  Electromagnetic Methods in Applied Geophysics: Voume 1, Theory , 1988 .

[14]  Chester J. Weiss,et al.  Adaptive finite-element modeling using unstructured grids: The 2D magnetotelluric example , 2005 .

[15]  Toshihiro Uchida,et al.  3D magnetotelluric modeling using the T‐Ω finite‐element method , 2004 .

[16]  J. G. Paine,et al.  APPLYING AIRBORNE ELECTROMAGNETIC INDUCTION IN GROUND- WATER SALINIZATION AND RESOURCE STUDIES, WEST TEXAS , 2003 .

[17]  G. Newman,et al.  Frequency‐domain modelling of airborne electromagnetic responses using staggered finite differences , 1995 .

[19]  Rita Streich,et al.  3D finite-difference frequency-domain modeling of controlled-source electromagnetic data: Direct solution and optimization for high accuracy , 2009 .

[20]  Greg Hodges,et al.  Simulated annealing for airborne EM inversion , 2007 .

[21]  Frank A. Maaø,et al.  Fast finite-difference time-domain modeling for marine-subsurface electromagnetic problems , 2007 .

[22]  Colin Farquharson,et al.  A finite-volume solution to the geophysical electromagnetic forward problem using unstructured grids , 2014 .

[23]  Hansruedi Maurer,et al.  A goal-oriented adaptive finite-element approach for plane wave 3-D electromagnetic modelling , 2013 .

[24]  Douglas W. Oldenburg,et al.  Three dimensional inversion of multisource time domain electromagnetic data , 2013 .

[25]  Jingtian Tang,et al.  3D direct current resistivity modeling with unstructured mesh by adaptive finite-element method , 2010 .

[26]  S. Silvestri,et al.  Surface water–groundwater exchange in transitional coastal environments by airborne electromagnetics: The Venice Lagoon example , 2010 .

[27]  Yin Chang.  Trans-dimensional Bayesian inversion of frequency-domain airborne EM data , 2014 .

[28]  O. Ernst,et al.  Fast 3-D simulation of transient electromagnetic fields by model reduction in the frequency domain using Krylov subspace projection , 2008 .

[29]  Patrick Amestoy,et al.  MUMPS : A General Purpose Distributed Memory Sparse Solver , 2000, PARA.

[30]  Birgit Jochum,et al.  A complex geo-scientific strategy for landslide hazard mitigation – from airborne mapping to ground monitoring , 2008 .

[31]  Christoph Schwarzbach,et al.  Three-dimensional adaptive higher order finite element simulation for geo-electromagnetics—a marine CSEM example , 2011 .

[32]  Douglas W. Oldenburg,et al.  3-D inversion of airborne electromagnetic data parallelized and accelerated by local mesh and adaptive soundings , 2014 .

[33]  S. Selberherr,et al.  Alternating-Direction Implicit Formulation of the Finite-Element Time-Domain Method , 2007, IEEE Transactions on Microwave Theory and Techniques.