Accounting for imperfect forward modeling in geophysical inverse problems — Exemplified for crosshole tomography

ABSTRACTInversion of geophysical data relies on knowledge about how to solve the forward problem, that is, computing data from a given set of model parameters. In many applications of inverse problems, the solution to the forward problem is assumed to be known perfectly, without any error. In reality, solving the forward model (forward-modeling process) will almost always be prone to errors, which we referred to as modeling errors. For a specific forward problem, computation of crosshole tomographic first-arrival traveltimes, we evaluated how the modeling error, given several different approximate forward models, can be more than an order of magnitude larger than the measurement uncertainty. We also found that the modeling error is strongly linked to the spatial variability of the assumed velocity field, i.e., the a priori velocity model. We discovered some general tools by which the modeling error can be quantified and cast into a consistent formulation as an additive Gaussian observation error. We teste...

[1]  T. Hansen,et al.  Inverse problems with non-trivial priors: efficient solution through sequential Gibbs sampling , 2012, Computational Geosciences.

[2]  A. Tarantola,et al.  Generalized Nonlinear Inverse Problems Solved Using the Least Squares Criterion (Paper 1R1855) , 1982 .

[3]  D. Oldenburg,et al.  METHODS FOR CALCULATING FRÉCHET DERIVATIVES AND SENSITIVITIES FOR THE NON‐LINEAR INVERSE PROBLEM: A COMPARATIVE STUDY1 , 1990 .

[4]  Vlastislav Cerveny,et al.  Fresnel volume ray tracing , 1992 .

[5]  Sebastien Strebelle,et al.  Conditional Simulation of Complex Geological Structures Using Multiple-Point Statistics , 2002 .

[6]  A. Buland,et al.  Bayesian linearized AVO inversion , 2003 .

[7]  T. Hansen,et al.  Identifying Unsaturated Hydraulic Parameters Using an Integrated Data Fusion Approach on Cross‐Borehole Geophysical Data , 2006 .

[8]  J. Vidale Finite-difference calculation of travel times , 1988 .

[9]  Albert Tarantola,et al.  Inverse problem theory - and methods for model parameter estimation , 2004 .

[10]  T. Hansen,et al.  Monte Carlo full-waveform inversion of crosshole GPR data using multiple-point geostatistical a priori information , 2012 .

[11]  Barbara Romanowicz,et al.  Inferring upper-mantle structure by full waveform tomography with the spectral element method , 2011 .

[12]  Liangguo Dong,et al.  Sensitivity kernels for seismic Fresnel volume tomography , 2009 .

[13]  A. Christiansen,et al.  Quasi-3D modeling of airborne TEM data by spatially constrained inversion , 2008 .

[14]  B. Minsley A trans-dimensional Bayesian Markov chain Monte Carlo algorithm for model assessment using frequency-domain electromagnetic data , 2011 .

[15]  Albert Tarantola,et al.  Theoretical background for the inversion of seismic waveforms including elasticity and attenuation , 1988 .

[16]  M. Sambridge,et al.  Monte Carlo analysis of inverse problems , 2002 .

[17]  Jeffrey W. Roberts,et al.  Estimation of permeable pathways and water content using tomographic radar data , 1997 .

[18]  Erik H. Saenger,et al.  Finite-difference modeling of viscoelastic and anisotropic wave propagation using the rotated staggered grid , 2004 .

[19]  W. K. Hastings,et al.  Monte Carlo Sampling Methods Using Markov Chains and Their Applications , 1970 .

[20]  Stephan Husen,et al.  Local earthquake tomography between rays and waves: fat ray tomography , 2001 .

[21]  Mark L. Moran,et al.  Radar signature of a 2. 5-D tunnel , 1993 .

[22]  Partha S. Routh,et al.  Crosshole radar velocity tomography with finite-frequency Fresnel volume sensitivities , 2008 .

[23]  Peter G. Lelièvre,et al.  Inversion of first-arrival seismic traveltimes without rays, implemented on unstructured grids , 2011 .

[24]  Niels Bohr,et al.  Monte Carlo sampling of solutions to inverse problems , 2004 .

[25]  Knud Skou Cordua,et al.  Quantifying the influence of static-like errors in least-squares-based inversion and sequential simulation of cross-borehole ground penetrating radar data. , 2009 .

[26]  A. Tarantola,et al.  Inverse problems = Quest for information , 1982 .

[27]  Guust Nolet,et al.  Three-dimensional sensitivity kernels for finite-frequency traveltimes: the banana–doughnut paradox , 1999 .

[28]  Andrea Viezzoli,et al.  Quantification of modeling errors in airborne TEM caused by inaccurate system description , 2011 .

[29]  P. Fullagar,et al.  Radio tomography and borehole radar delineation of the McConnell nickel sulfide deposit, Sudbury, Ontario, Canada , 2000 .

[30]  Marta Woodward,et al.  Wave-equation tomography , 1992 .

[31]  Jacques R. Ernst,et al.  Full-Waveform Inversion of Crosshole Radar Data Based on 2-D Finite-Difference Time-Domain Solutions of Maxwell's Equations , 2007, IEEE Transactions on Geoscience and Remote Sensing.

[32]  Knud Skou Cordua,et al.  SIPPI: A Matlab toolbox for sampling the solution to inverse problems with complex prior information: Part 2 - Application to crosshole GPR tomography , 2013, Comput. Geosci..

[33]  M. Chouteau,et al.  Massive sulphide delineation using borehole radar: tests at the McConnell nickel deposit, Sudbury, Ontario , 2001 .

[34]  R. Snieder,et al.  The Fresnel volume and transmitted waves , 2004 .

[35]  Albert Tarantola,et al.  Monte Carlo sampling of solutions to inverse problems , 1995 .

[36]  J. J. Peterson Pre-inversion Corrections and Analysis of Radar Tomographic Data , 2001 .

[37]  Knud Skou Cordua,et al.  SIPPI: A Matlab toolbox for sampling the solution to inverse problems with complex prior information: Part 1 - Methodology , 2013, Comput. Geosci..

[38]  Albert Tarantola,et al.  Probabilistic Approach to Inverse Problems , 2002 .

[39]  Stephan Husen,et al.  Local earthquake tomography between rays and waves : fat ray tomography , 2001 .

[40]  Michael D. Knoll,et al.  Multivariate analysis of cross‐hole georadar velocity and attenuation tomograms for aquifer zonation , 2004 .

[41]  Bo Holm Jacobsen,et al.  Sensitivity Kernels for Time-Distance Inversion , 2000 .

[42]  Qinya Liu,et al.  Tomography, Adjoint Methods, Time-Reversal, and Banana-Doughnut Kernels , 2004 .

[43]  B. Neil Cuffin,et al.  Effects of modeling errors on least squares error solutions to the inverse problem of electrocardiology , 1981, Annals of Biomedical Engineering.

[44]  Knud Skou Cordua,et al.  Accounting for Correlated Data Errors during Inversion of Cross‐Borehole Ground Penetrating Radar Data , 2008 .

[45]  Andrew Binley,et al.  Monitoring unsaturated flow and transport using cross-borehole geophysical methods , 2006 .

[46]  D. Schmitt,et al.  First-break timing: Arrival onset times by direct correlation , 1999 .

[47]  A. Morelli Inverse Problem Theory , 2010 .

[48]  O. Olsson,et al.  BOREHOLE RADAR APPLIED TO THE CHARACTERIZATION OF HYDRAULICALLY CONDUCTIVE FRACTURE ZONES IN CRYSTALLINE ROCK1 , 1992 .

[49]  Guust Nolet,et al.  Fréchet kernels for finite-frequency traveltimes—I. Theory , 2000 .