@article {Miensopust2013,
	title = {{Magnetotelluric 3-D inversion{\textendash}a review of two successful workshops on forward and inversion code testing and comparison}},
	journal = {Geophysical Journal International},
	volume = {193},
	number = {3},
	year = {2013},
	month = {mar},
	pages = {1216{\textendash}1238},
	abstract = {Over the last half decade the need for, and importance of, three-dimensional (3-D) modelling of magnetotelluric (MT) data have increased dramatically and various 3-D forward and inversion codes are in use and some have become commonly available. Comparison of forward responses and inversion results is an important step for code testing and validation prior to {\textquoteright}production{\textquoteright} use. The various codes use different mathematical approximations to the problem (finite differences, finite elements or integral equations), various orientations of the coordinate system, different sign conventions for the time dependence and various inversion strategies. Additionally, the obtained results are dependent on data analysis, selection and correction as well as on the chosen mesh, inversion parameters and regularization adopted, and therefore, a careful and knowledge-based use of the codes is essential. In 2008 and 2011, during two workshops at the Dublin Institute for Advanced Studies over 40 people from academia (scientists and students) and industry from around the world met to discuss 3-D MT inversion. These workshops brought together a mix of code writers as well as code users to assess the current status of 3-D modelling, to compare the results of different codes, and to discuss and think about future improvements and new aims in 3-D modelling. To test the numerical forward solutions, two 3-D models were designed to compare the responses obtained by different codes and/or users. Furthermore, inversion results of these two data sets and two additional data sets obtained from unknown models (secret models) were also compared. In this manuscript the test models and data sets are described (supplementary files are available) and comparisons of the results are shown. Details regarding the used data, forward and inversion parameters as well as computational power are summarized for each case, and the main discussion points of the workshops are reviewed. In general, the responses obtained from the various forward models are comfortingly very similar, and discrepancies are mainly related to the adopted mesh. For the inversions, the results show how the inversion outcome is affected by distortion and the choice of errors, as well as by the completeness of the data set. We hope that these compilations will become useful not only for those that were involved in the workshops, but for the entire MT community and also the broader geoscience community who may be interested in the resolution offered by MT. {\textcopyright} The Authors 2013. Published by Oxford University Press on behalf of The Royal Astronomical Society.},
	keywords = {Geomagnetic induction, Inverse theory, Magnetotelluric, Numerical solutions},
	issn = {0956-540X},
	doi = {10.1093/gji/ggt066},
	url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-84879858225\&partnerID=tZOtx3y1},
	author = {Miensopust, M. P. and Queralt, P. and Jones, A. G.}
}
@article {Kaser2008,
	title = {{Quantitative accuracy analysis of the discontinuous Galerkin method for seismic wave propagation}},
	journal = {Geophysical Journal International},
	volume = {173},
	number = {3},
	year = {2008},
	month = {jun},
	pages = {990{\textendash}999},
	abstract = {We present a quantitative accuracy analysis of the Discontinuous Galerkin Finite-Element method for the simulation of seismic wave propagation on tetrahedral meshes. Several parameters are responsible for the accuracy of results, such as the chosen approximation order, the spatial discretization, that is, number of elements per wavelength, and the propagation distance of the waves due to numerical dispersion and dissipation. As error norm we choose the time-frequency representation of the envelope and phase misfit of seismograms to assess the accuracy of the resulting seismograms since this provides the time evolution of the spectral content and allows for the clear separation of amplitude and phase errors obtained by the numerical method. Our results can be directly used to set up the necessary modelling parameters for practical applications, such as the minimum approximation order for a given mesh spacing to reach a desired accuracy. Finally, we apply our results to the well-acknowledged LOH.1 and LOH.3 problems of the SPICE Code Validation project, including heterogeneous material and the free surface boundary condition, and compare our solutions with those of other methods. In general, we want to stress the increasing importance of certain standard procedures to facilitate future code validations and comparisons of results in the community of numerical seismology. {\textcopyright} 2008 The Authors Journal compilation {\textcopyright} 2008 RAS.},
	keywords = {Computational seismology, Numerical approximations and analysis, Numerical solutions, Time series analysis, Wave propagation, Wavelet transform},
	issn = {0956540X},
	doi = {10.1111/j.1365-246X.2008.03781.x},
	url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-43749087643\&partnerID=tZOtx3y1},
	author = {K{\"a}ser, Martin and Hermann, Verena and de la Puente, Josep}
}
