Software

**GREEN3D**,
release March 2010. The MatLab shell of the Fortran 77 library
GREENLIB for computing the normal fields and volume integrals of
electromagnetic Green's tensors. This program is designed to help
the development of electromagnetic modeling and inversion
programs. It is an easy-to-use MATLAB function which can be called
up anywhere in the MATLAB environment. Using this library, the
software developer is freed from coding the excessively complex
algorithms for Green's tensors and different electromagnetic
fields in a layered medium.

Author: Gabor Hursan

References:

Xiong, Z., 1992, EM modeling of three-dimensional structures by
the method of system iteration using integral equations,
Geophysics, **57**, 1556-1561.

Zhdanov, M. S., and G. V. Keller, 1994, The geoelectrical methods
in geophysical exploration: Elsevier, 873 pp.

G. Hursan, 1999, A Fortran 77 Library for Computing the Normal
Fields and Volume Integrals of Electromagnetic Green's Tensors:
Proceedings of the CEMI 1999 Annual Meeting.

**GT3D**, release
March 2001. The Matlab software package for computing
electromagnetic Green's tensor functions in horizontally layered
bi-anisotropic medium. This program is designed to help the
development of electromagnetic modeling and inversion programs. It
is an easy-to-use MATLAB function which can be called up anywhere
in the MATLAB environment. Using this library, the software
developer is freed from coding the excessively complex algorithms
for Green's tensors and different electromagnetic fields in a
horizontally layered medium with anisotropy in both magnetic and
electric properties.

Author: Arvidas Cheryauka

References: Cheryauka, A., and M. S. Zhdanov, 2001,
Electromagnetic tensor Green's functions and their integrals in
transverse isotropic layered media: Proceedings of CEMI 2001
Annual Meeting.

**FWDTIWL3D**,
release March 2007. 3-D forward modeling code of tensor induction
well-logging (TIWL) instrument responses. The code is based on
INTEM3DQL - integral equation modeling code (Hursan and Zhdanov,
2002) with multi-grid quasi-linear approximation (Ueda and
Zhdanov, 2006). The release includes a graphical user interface
(GUI) for convinient way of designing model and displaying the
results. The code is written in Matlab language.

Authors: Alex Gribenko and Michael S. Zhdanov.

References:

Hursan, G., and M. S. Zhdanov, 2002, Contraction integral equation
method in three-dimensional electromagnetic modeling: Radio
Science, 37 (6), 1089,
doi: 10.1029/ 2001RS002513.

Ueda, T., and M. S. Zhdanov, 2006, Fast numerical modeling of
multitransmitter electromagnetic data using multigrid quasi-linear
approximation: IEEE Transactions on Geoscience and Remote Sensing:
44, 1428-1434.

**INTEM3DIP ver. 2010**, release
March 2011. The Matlab software package for forward modeling of a
3D electromagnetic field based on the IE method. This code is
designed for simulating frequency domain EM responses of a 3D
complex conductivity structure in horizontally layered earth with
complex conductivities. In addition to the same forward modeling
routines as in the INTEM3D Matlab code, the package includes a new
routine which is based on the multigrid quasilinear (MGQL)
approximation. This program can work with Matlab 2006 and with the
latest versions including Matlab 2009. The sources used in the
program are the same as in GREEN3D and INTEM3D:

- plane wave propagating vertically toward the earth
(magnetotelluric);

- current bipoles along the x, y, and z directions;

- horizontal rectangular loop:

- horizontal circular loop;

- moving horizontal loops;

- magnetic dipoles oriented in the x, y, and z directions.

Authors: Masashi Endo and Michael Zhdanov

Hursan, G., and M. S. Zhdanov, 2002, Contraction integral
equation method in three-dimensional electromagnetic modeling:
Radio Sci., 37 (6), 1089,
doi: 10.1029/ 2001RS002513.

Ueda, T., and M. S. Zhdanov, 2006, Fast numerical modeling of
multitransmitter electromagnetic data using multigrid quasi-linear
approximation: IEEE Transactions in Geoscience and Remote Sensing,
44, 1428-1434.

Zhdanov, M. S., 2002, Geophysical inverse theory and
regularization problems: Elsevier.

**IBCEM3D ver. 2009**,
release March 2010. The Matlab software package for 3D modeling of
electromagnetic fields in a 3D\ complex conductivity structure
with complex inhomogeneous background conductivity. The code uses
the contraction integral equation (CIE) method for the solution of
frequency domain EM field integral equations. This program can
work with Matlab 2006 and with the latest versions including
Matlab 2009. The responses are computed in double precision. The
sources used in the program are the same as in INTEM3DQL:

- plane wave propagating vertically toward the earth
(magnetotelluric);

- current bipoles along the x, y, and z directions;

- horizontal rectangular loop:

- horizontal circular loop;

- moving horizontal loops;

- magnetic dipoles oriented in the x, y, and z directions.

Authors: Masashi Endo and Michael Zhdanov

Hursan, G., and M. S. Zhdanov, 2002, Contraction integral
equation method in three-dimensional electromagnetic modeling:
Radio Sci., 37 (6), 1089,
doi: 10.1029/ 2001RS002513.

Ueda, T., and M. S. Zhdanov, 2006, Fast numerical modeling of
multitransmitter electromagnetic data using multigrid quasi-linear
approximation: IEEE Transactions in Geoscience and Remote Sensing,
44, 1428-1434.

Zhdanov, M. S., S. K. Lee, and K. Yoshioka, 2006, Integral
equation method for 3D modeling of electromagnetic fields in
complex structures with inhomogeneous background conductivity:
Geophysics, 71 (6),
G333-G345, doi: 10.1190/ 1.2358403.

**PIE3D ver. 2013**,
Release March 2014. The PIE3D ver. 2013 is parallel EM forward
modeling software based on the IE method. PIE3D ver. 2013 is
designed for distributed memory machines (e.g., PC clusters) and
is portable on any computer that supports message passing
interface (MPI). This code simulates frequency-domain EM responses
of multiple-domain (MD) 3D anomalous resistivity structures in a
horizontally layered medium.

For this release we have improved the performance of the GMRES
solver by using overlap of communication of the domain field
vector with the calculation of the field vector - Greens matrix
product. This is allowed by the new MPI 3.0 standard support for
nonblocking collective communication; therefore an MPI
distribution that supports MPI 3.0 is required for this feature.

We also release a modified GREEN3D library that supports arbitrary
orientation of a horizontal electric bipole. This feature is
useful for more complicated bipole source shapes. This new source
is incorporated in the PIE3D modeling as well.

Authors: Martin Cuma and Michael Zhdanov

Endo, M., M. Čuma, and M. S. Zhdanov, 2009,
Application of a multiple-domain, integral-equation method for 3D
electromagnetic modeling in complex geoelectrical structures:
Proceedings of the Annual Meeting, Consortium for Electromagnetic
Modeling and Inversion, 27-48.

Endo, M., M. Čuma, and Zhdanov, M. S., 2009,
Large-scale electromagnetic modeling for multiple inhomogeneous
domains: Communications in Computational Physics, 6, 269-289.

Hursán, G., and M. S. Zhdanov, 2002,
Contraction integral equation method in three-dimensional
electromagnetic modeling: Radio Science, 37 (6), 1089, doi:
10.1029/ 2001RS002513.

Yoshioka, K., and M. S. Zhdanov, 2005,
Electromagnetic forward modeling based on the integral equation
method using parallel computers: Proceedings of the Annual
Meeting, Consortium for Electromagnetic Modeling and Inversion,
25-44.

Yoshioka, K., and M. S. Zhdanov, 2006, Modeling
large-scale geoelectrical structures with inhomogeneous
backgrounds using the integral equation method: application to the
bathymetry effects in marine CSEM data: Proceedings of the Annual
Meeting, Consortium for Electromagnetic Modeling and Inversion,
159-180.

Zhdanov, M. S., S. K. Lee, and K. Yoshioka,
2006, Integral equation method for 3D modeling of electromagnetic
fields in complex structures with inhomogeneous background
conductivity: Geophysics, 71 (6), G333-G345, doi:
10.1190/1.2358403.

Ueda, T., and M. S. Zhdanov, 2006, Fast
numerical modeling of multitransmitter electromagnetic data using
multigrid quasi-linear approximation: IEEE Transactions in
Geoscience and Remote Sensing, 44, 1428-1434.

Zhdanov, M. S., 2002, Geophysical inverse
theory and regularization problems: Elsevier.

**LQLBH3DTI**,
version 1.0. Matlab software package for 3-D imaging of tensor induction
well logging (TIWL) data, collected in a single borehole.
The package includes a visualization tool to represent the volume
image around a borehole, and the arbitrarily selective
cross-sections and depth-slices of the reconstructed conductivity.
The inversion algorithm is based on the LQL approximation of the
forward modeling operator and re-weighted regularized conjugate
gradient inversion with the option of smoothed and focusing
imaging.

Authors: Michael S. Zhdanov, Alex Gribenko, and Efthimios
Tartaras.

References: Tartaras, E., Gribenko, A., and M. S. Zhdanov, 2002,
Fast Inversion of Single-hole EM Induction Data Proceedings of the
CEMI 2002 Annual Meeting.

**MT3D ver. 2013**,
release March 2014. Release March 2014. Matlab software package
for 3D inversion of the magnetotelluric (MT), magnetovariational
(MV), and Z-tipper (ZTEM) data. The predicted data are calculated
rigorously by the PIE3D integral equation (IE) modeling code
(Hursán and Zhdanov, 2002). The fast Fréchet
derivative computation is based on the quasi-Born (QB)
approximation (Gribenko et al., 2010). The standard approach of
minimizing the Tikhonov parametric functional (Tikhonov and
Arsenin, 1977) is realized in the code. The regularized
conjugate-gradient method with adaptive regularization is used for
the parametric functional minimization (Zhdanov, 2002).

New features of the code are 1D inversion of the principal
impedance data to obtain an initial model. Besides 3D conductivity
distribution, the code recovers the full impedance distortion
tensor (Groom and Bailey, 1989). One of the novel features of the
code is automatic static shift correction based on the
simultaneous inversion for the components of the distortion
tensor. Variable sensitivity domain size is computed based on skin
depth for each frequency.

The code outputs 3D conductivity distribution, predicted impedance
and/or tipper data, and RMS misfit values. The solution and
predicted fields can be visualized by the code.

Authors: Alexander Gribenko, VirginiaMaris, Michael S. Zhdanov,
and Michael Jorgensen

References:

Hursan, G., and M. S. Zhdanov, 2002, Contraction integral equation
method in three-dimensional electromagnetic modeling: Radio
Science, 37 (6), 1089,
doi: 10.1029/ 2001RS002513.

Gribenko, A., and M. S. Zhdanov, 2007a, Rigorous 3D inversion of
marine CSEM data based on the integral equation method:
Geophysics, 72, WA73.

Gribenko, A., and M. S. Zhdanov, 2007b, Regularized focusing
inversion of marine CSEM data using minimum vertical support
stabilizer: 77th Annual International Meeting, SEG, Expanded
Abstracts, 579-583.

Groom, R. W., and R. C. Bailey, 1989, Decomposition of
magnetotelluric impedance tensors in the presence of local three
dimensional galvanic distortion: Journal of Geophysical Research,
94, 1913-1925.

Tikhonov, A. N., and V. Y. Arsenin, 1977, Solution of ill-posed
problems: V. H. Wilson and Sons.

Zhdanov, M. S., 2002, Geophysical inverse theory and
regularization problems: Elsevier

**MCSEM3D ver. 2012**,
Release March 2013. Matlab software package for 3D inversion of
the marine controlled source electromagnetic (MCSEM) data. The
predicted data are calculated rigorously by the PIE3D integral
equation (IE) modeling code. The fast Fréchet derivative
computation is based on the quasi-Born (QB) approximation
(Gribenko et al., 2010). The standard approach of minimizing the
Tikhonov parametric functional (Tikhonov and Arsenin, 1977) is
realized in the code. The regularized conjugategradient method
with re-weightings and adaptive regularization is used for
parametric functional minimization (Zhdanov, 2002). At the first
stage, the code uses a minimum norm stabilizer, minimum gradient
stabilizers, or their combination, which produces smooth
conductivity distributions (Gribenko and Zhdanov, 2011). At the
consequent stages (re-weightings), the user has a choice of
minimum norm, minimum support (Portniaguine and Zhdanov, 1999),
minimum vertical support (Zhdanov et al., 2007) stabilizers, or
their combination. Appropriate selection of the stabilizing
functional allows the user to find a solution with sharp
geoelectrical boundaries.

Unlike the previous versions, the code allows several transmitter
lines with inline MCSEMdata. The code uses the parallel version of
the 3D electromagnetic (EM) forward modeling code (PIE3D). MCSEM3D
is written in the MATLAB language for the versions 2006b or later.
MATLAB license is required to run MCSEM3D. MCSEM3D is platform
independent.,

Authors: Alexander Gribenko, Daeung Yoon, and Michael S.
Zhdanov

References:

Hursán, G., and M. S. Zhdanov, 2002,
Contraction integral equation method in three-dimensional
electromagnetic modeling: Radio Science, 37 (6), 1089, doi:

10.1029/ 2001RS002513.

Gribenko, A., and M. S. Zhdanov, 2010, Rigorous 3D inversion of
marine CSEM data based on the integral equation method:
Geophysics, 72, WA73.

Gribenko, A., and M. S. Zhdanov, 2011, Joint inversion of MT and
MCSEM data in off-shore exploration: Proceedings of 2011 CEMI
Annual Meeting.

Gribenko, A., L. Wan, and M. S. Zhdanov, 2010, Three-dimensional
inversion of magnetotelluric data for complex resistivity:
Proceedings of 2010 CEMI Annual

Meeting, 269-294.

Gribenko, A., A. M. Green, M. Cuma, and M. S. Zhdanov, 2010,
Efficient 3D inversion of MT data using integral equations method
and the receiver footprint approach:

application to the large-scale inversion of the EarthScope MT
data: 80th Annual InternationalMeeting, SEG, Expanded Abstracts,
655-659, doi:10.1190/1.3513865.

Portniaguine, O., and M. S. Zhdanov, 1999, Focusing geophysical
inversion images: Geophysics, 64, 874-887.

Tikhonov, A. N., and V. Y. Arsenin, 1977, Solution of ill-posed
problems: V. H. Winston and Sons.

Zhdanov, M. S., 2002, Geophysical inverse theory and
regularization problems: Elsevier.

Zhdanov, M.S., 2009, Geophysical electromagnetic theory and
methods: Elsevier.

Zhdanov, M. S., A. Gribenko, and M. Cuma, 2007, Regularized
focusing inversion of marine CSEM data using minimum
vertical-support stabilizer: 77th Annual International Meeting,
SEG, Expanded Abstracts, 579-583.

**MCSEM_MT3D ver. 2012. **Release
March 2013. Matlab software package for joint 3D inversion of the
marine controlled source electromagnetic (MCSEM) and
magnetotelluric (MT) data. The predicted data are calculated
rigorously by the PIE3D integral equation (IE) modeling code. The
fast Fréchet derivative computation is based on the
quasi-Born (QB) approximation (Gribenko et al., 2010). The
standard approach of minimizing the Tikhonov parametric functional
(Tikhonov and Arsenin, 1977) is realized in the code. The
regularized conjugate-gradient method with re-weightings and
adaptive regularization is used for the parametric functional
minimization (Zhdanov, 2002). At the first stage the code uses a
minimum norm stabilizer, minimum gradient stabilizers, or their
combination, which produces smooth conductivity distributions
(Gribenko and Zhdanov, 2011). At the consequent stages
(re-weightings) the user has a choice of minimum norm, minimum
support (Portniaguine and Zhdanov, 1999), minimum vertical support
(Zhdanov et al., 2007) stabilizers, or their combination.
Appropriate selection of the stabilizing functional allows the
user to find a solution with sharp geoelectrical boundaries. An
adaptive data weighting technique is implemented in the code.

Unlike the previous versions, the code allows several transmitter
lines with in-line MCSEM data. The code uses the parallel version
of the 3D electromagnetic (EM) forward modeling code (PIE3D).
MCSEM3D_MT3D is written in MATLAB language for the versions 2006b
or later. MATLAB license is required to run MCSEM_MT3D. MCSEM_MT3D
is platform independent.

Authors: Alexander Gribenko and Michael S.
Zhdanov

References:

Hursán, G., and M. S. Zhdanov, 2002,
Contraction integral equation method in three-dimensional
electromagnetic modeling: Radio Science, 37 (6), 1089, doi:

10.1029/ 2001RS002513.

Gribenko, A., and M. S. Zhdanov, 2010, Rigorous 3D inversion of
marine CSEM data based on the integral equation method:
Geophysics, 72, WA73.

Gribenko, A., and M. S. Zhdanov, 2011, Joint inversion of MT and
MCSEM data in off-shore exploration: Proceedings of 2011 CEMI
Annual Meeting.

Gribenko, A., L. Wan, and M. S. Zhdanov, 2010, Three-dimensional
inversion of magnetotelluric data for complex resistivity:
Proceedings of 2010 CEMI Annual

Meeting, 269-294.

Gribenko, A., A. M. Green, M. Cuma, and M. S. Zhdanov, 2010,
Efficient 3D inversion of MT data using integral equations method
and the receiver footprint approach:

application to the large-scale inversion of the EarthScope MT
data: 80th Annual InternationalMeeting, SEG, Expanded Abstracts,
655-659, doi:10.1190/1.3513865.

Portniaguine, O., and M. S. Zhdanov, 1999, Focusing geophysical
inversion images: Geophysics, 64, 874-887.

Tikhonov, A. N., and V. Y. Arsenin, 1977, Solution of ill-posed
problems: V. H. Winston and Sons.

Zhdanov, M. S., 2002, Geophysical inverse theory and
regularization problems: Elsevier.

Zhdanov, M.S., 2009, Geophysical electromagnetic theory and
methods: Elsevier.

Zhdanov, M. S., A. Gribenko, and M. Cuma, 2007, Regularized
focusing inversion of marine CSEM data using minimum
vertical-support stabilizer: 77th Annual International Meeting,
SEG, Expanded Abstracts, 579-583.

**GRMAG3DTOPO ver. 2010**,
release March 2011. The software is designed for 3D inversion of
the vertical component of the gravity field or any gravity
gradient component collected on a variable surface, including the
option for joint inversion of these components. It will also
invert the total magnetic field under the assumption that the
anomalous field is caused by induced magnetization only. This
program converts the anomalous data, measured on an irregular grid
over a variable surface, into a volume image or model of
subsurface density or magnetic susceptibility distribution. It
will conform the modeling domain to match given topography, which
reduces computation cost by facilitating a more effective
discretization of the model space. For inversion, the code uses
the approach known as the Re-weighted Regularized Conjugant
Gradient method or RRCG method. It also utilizes a technique to
naturally imposed model constraints by computing iterations in the
space of logarithmic model parameters.

Release 2010 has been tested in Matlab R2010b. We have
incorporated the calculation of all gravity field and tensor
components using the point approximation. We also modified the
Total Magnetic Intensity calculation kernel to use SI units (e.g.,
collected by the Fugro FALCON system).

Authors: Martin Cuma and Michael S. Zhdanov

References:

Zhdanov, M. S., 2002, Geophysical inverse theory and
regularization problems: Elsevier.

Zhdanov, M. S., R. G. Ellis, and S. Mukherjee, 2004, Regularized
focusing inversion of 3-D gravity tensor data: Geophysics, 69, 925-937.

Jessop, M., and M. S. Zhdanov, 2005, Focusing inversion of gravity
gradient data collected on an arbitrary observation surface:
Proceedings of 2005 CEMI Annual Meeting.

**PF3D ver. 2011**,
Release March 2012. The PF3D ver. 2011 is a MATLAB software
package for 3D modeling and inversion of potential field data
which includes magnetic field, magnetic gradient tensor
components, gravity field, and gravity gradient tensor components.
The code is designed for 3D inversion of the data collected on a
variable surface, including the option for joint inversion of the
different gravity or magnetic field and tensor field components.
For inversion, the code uses the approach known as the re-weighted
regularized conjugant gradient method, or RRCG method, with
focusing stabilizers to produce compact geophysical images. It
also utilizes a technique to naturally impose model constraints by
computing iterations in the space of logarithmic model parameters.

Authors: Martin Cuma and Michael S. Zhdanov

References:

Portniaguine, O., and M. S. Zhdanov, 1999,
Focusing geophysical inversion images: Geophysics, 64, 874-887.

Zhdanov, M. S., 2002, Geophysical inverse
theory and regularization problems: Elsevier.

**GG3Dmigration ver. 2013**,
Release March 2014.The GG3Dmigration ver. 2014 is a MATLAB
software package for migration of the gravity and/or gravity
gradiometry data in order to image a 3D density distribution. The
gravity and/or gravity gradiometry data can be collected on a
variable surface. The major novel feature of the code is the
ability to select an arbitrary combination of gravity field and
gravity tensor components and migrate them jointly. The migration
can be done on a large scale and within an arbitrary selected
domain. The software package includes the source code, user manual
and examples. Also, it includes a code to produce the
cross-section image for a convenience. The software is easy to
maintain and to use.

Authors: Le Wan and Michael S. Zhdanov

References:

Zhdanov, M. S., X. Liu, G. A. Wilson, and L.
Wan, 2011, Potential field migration for rapid imaging of gravity
gradiometry data: Geophysical Prospecting, 59, 1052--1071.

**LQL-interface**,
release April 2003. User friendly
interface for LQLINV3D
code

Author: Ekaterina Tolstaya.

**GRMAG-interface**.
User friendly interface for GRMAG3D code