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TDMIGR1, Release
from 1996.
Time Domain Electromagnetic Migration This is an interpretation program
for 2D time domain data sets, which allows to obtain migration apparent
resistivity of geoelectrical crosssection. Could be applied for both
fixed transmitter and slingram mode.
Author: M.S. Zhdanov and O. Portniaguine
Reference: Michael S. Zhdanov, Peter Traynin and Oleg Portniaguine,
1995, Resistivity Imaging by Time Domain Electromagnetic Migration
(TDEMM): Exploration Geophysics, 25, 186-194.
IMAGE, Release
from 1986.
Rapid inversion of transient electromagnetic responses. At each time
this
program fits the magnetic field of the transmitting wire to the fields
recorded
at the surface of a quasi-layered earth due to a step current waveform.
Based
on the inversion of an estimate of the vertical component of the
diffusion
velocity, the resistivity of the earth as a function of the (scaled)
depth is
determined. Either loop-source or grounded-source data may be
processed.
Author: Perry A. Eaton Current version from April 1994. Original
version from
1985, 1986.
Reference: Eaton, P.A. and Hohmann, G.W., 1989, A rapid inversion
technique for transient
electromagnetic soundings: Physics of the Earth and Planetary
Interiors, 53,
394-404.
GRAD2D.
An imaging program for AEM and airborne
magnetic data. It is based on the idea of using downward continuation
and total
normalized gradient. This method was developed initially for potential
fields
by V.M. Berezkin in Russia in 1973. Modified to work with 2D frequency
domain
airborne data. Produces geometrical images of possible targets.
Authors: P.N. Traynin and M.S. Zhdanov
References: Berezkin, V.M., 1973, Method of total normalized gradient,
Nedra
publishing, Moscow 354 p (in Russian).
SINVERSE-1,
release March, 1998.
Fast imaging code for TEM data interpretation
based on S-inversion. Fast S-inversion is a method of interpretation of
time
domain electromagnetic (TDEM) sounding data using the thin sheet model
approach. Within the framework of this method the electromagnetic
response
measured at the surface of the earth at every time moment is matched
with that
of a thin sheet model. The conductivity change with depth is obtained
using the
con- ductance, S, and depth, d, of the equivalent thin sheet.
Authors: Dmitriy Pavlov, Oleg Portniaguine, Efihimios Tartaras, and
Michael
Zhdanov.
References:
Tartaras, E., and Zhdanov, M. S., 1996, S-inversion in time domain:
method of interpretation using the thin sheet approach: CEMI 1996
Annual
Report.
Tartaras, E., and Zhdanov, M. S., 1996, Fast S-inversion in the time
domain: method of interpretation using the thin sheet approach: 66th
Ann.
Internat. Mtg., Soc. Expl. Geophys., Expanded Abstracts, 1306-1309.
PLT3D,
release March 2000.
This MatLab subroutine is designed for
visualization of 3-D datasets. It is called up by main codes from the
EMLAB
package to allow the user to view 3-D model parameter distribution,
field
values, results of inversion, etc. It can also be used as a subroutine
for
software development.
Author: Oleg Portniaguine
SYSEM,
release 6, July 1996.
Electromagnetic modeling of a three-dimensional structure embedded in a
multi-layer anisotropic earth, using integral equations approach. This
program
is designed for EM modeling of a 3D structure in a multi-layer
anisotropic
earth. The location and the shape of the 3D structure can be arbitrary.
The
excitations include most sources in geophysical practice which are:
current
bipoles along x, y and z (vertical) directions, horizontal rectangular
loop,
horizontal circular loop, moving horizontal loops (including loop-loop
system),
moving vertical magnetic dipoles (including vertical co- planar and
vertical
co-axis magnetic dipoles), moving horizontal magnetic dipoles
(including
horizontal co-axis and horizontal co- planar magnetic dipoles),
arbitrary
magnetic dipoles, and plane waves propagating vertically toward the
earth
(magnetotellurics). The moving loop and magnetic dipoles can be used
either in
airborne, ground, or in downhole surveys. Using two horizontal current
bipoles
in the x and y directions one can also compute tensor CSAMT responses.
All
sources and receivers are allowed to be placed arbitrarily in space.
The
modeling problems are formulated in the frequency domain. For
controlled source
problems corresponding time domain solutions due to a step turn-on with
an
exponential ramp can be obtained via internal Fourier transforms.
Program works
in wide frequency range (up to 30 MHz). Computation of IP effects can
be
included.
Author: Zonghou Xiong
Reference: Xiong Z. and A.C. Tripp, 1993, Scattering matrix evaluation
using spatial
symmetry in electromagnetic modeling, Geophysical Journal
International,
114, 459-464.
SYSEMQL v. 2.
Release from March 1996.
This is second version of SYSEMQL. Uses tensor lambda. Allows
time-domain
calculations.
Author: Sheng Fang and M.S.Zhdanov
Reference: Zhdanov, M.S.,
Fang Sh., Rapid 3D Electromagnetic modeling based on quasi linear
approximation, Geophysics, 61, 646-665.
TEM3DL,
Version 1.1, February 1996.
TEM3DL calculates the diffusive transient EM field response of a 3D
structure
by using a finite-difference method. The code allows for arbitrary
model
geometries, conductivity variations and magnetic permeability
variations,up to
the resolution limits of the grid. The fundamental source geometries
are
electric and magnetic dipoles. A source of arbitrary geometry is built
up using
electric dipoles. The built-in source signatures are impulse and
step-on
functions, both of which are approximated by a Gaussian pulse. The
output is
the magnetic field (H) and/or their time derivatives, depending on the
input
data. The electric fields are not included for output in this version.
The code
can be used for the purposes of in-depth (borehole), ground, or
airborne
simulations. For airborne simulation, the transmitters are assumed to
be
magnetic dipoles that may be arbitrarily oriented.
Author: Tsili Wang
Reference: Wang, T, and Hohmann, G.W., 1993, A finite-difference
time-domain solution for
three-dimensional electromagnetic modeling: Geophys. pp.797-809.
EMIE3D,
This is integral equations program for simulating EM responses of
three-dimensional (3-D) resistivity structure in a layered earth for
magnetotelluric (MT), CSAMT, dipole- dipole resistivity/IP (layers and
body),
and loop-loop (including airborne) sources. Algorithm includes the
ability to
simulate 3-D structures which outcrop, which transect layer interfaces,
and
which extend indefinitely in one or more dimensions. Accuracy
improvements are
being incorporated at present and capability for downhole EM and
magnetic IP
responses is a near-term goal.
Author: P.E. Wannamaker
Reference:
Wannamaker, P. E., EMIE3D - v2.00, 1993, Integral equations algorithm
for
modeling magnetotelluric and finite source EM responses of
three-dimensional
bodies in layered earths, User documentation, 34 p..
Wannamaker, P. E., 1991, Advances in three-dimensional magnetotelluric
modeling using
integral equations, Geophysics, 56, 1716-1728.
Mackie, R. L., Madden, T. R., and Wannamaker, P. E., 1993,
Three-dimensional
magnetotelluric modeling using difference equations - theory and
comparison to
integral equations solutions, Geophysics, 58, 215-226.
PW2D,
Finite element program for simulation of plane-wave EM (MT and
far-field CSAMT)
responses over arbitrarily complex 2- D cross-sections including
topography.
High accuracy and stability of the responses has been achieved by
utilizing a
direct secondary field formulation for the field along strike. Both
transverse
electric (TE) and transverse magnetic (TM) modes may be modeled
individually or
in sequence.
Author: P.E. Wannamaker
Reference:
Wannamaker, P. E., Stodt, J. A., and Rijo, L., 1987, PW2D - finite
element
program for solution of magnetotelluric responses of two-dimensional
earth
resistivity structure: Program documentation, Univ. of Utah Research
Inst.
Rept. ESL-158, 72 p..
Wannamaker, P. E., Stodt, J. A., and Rijo, L., A stable finite element
solution
for two-dimensional magnetotelluric modelling, 1987, Geophys. J. Royal
Astr. Soc.,
88, 277-296.
ARJUNA V1.0.
EDITION 1.0,
Release from December, 1994.
Released by the mathematical geophysics group CRC for Australian
mineral
exploration technologies Macquarie University, NSW, 2109, Australia.
This
program is in part based on software developed at the University of
Utah by
Luis Rijo and Jerry Hohmann. As per agreement, this first release is
made
jointly to sponsors of AMIRA project 223B and the CEMI at Utah. The
program
calculates the time-domain EM response of a general heterogeneous 2-D
structure
excited by a 3-D source which we refer to as 2.5-D The full-waveform
time-domain response is computed for Sirotem, EM37, Utem, or
user-defined
systems.
Authors: F.Sugeng, Art Raiche Original version by Luis Rijo and Jerry
Hohmann.
GRDIP3,
Program GRDIP3 is an F77 routine to compute the D.C. electric field and
potential responses due to 3-D prisms embedded in a homogeneous
half-space.
GRDIP3 uses the method of volume integral equations to compute the
following
six types of output: (1) electric field E, (2) apparent resistivity
from E, (3)
IP phase from E, (4) potential V, (5) apparent resistivity from V, and
(6) IP
phase from V. These different outputs can be computed for multiple
transmitters
in either plan or section view.
Current version by: Craig W. Beasley (1988)
Original version by: Gerald W. Hohmann (1975)
Reference:
Hohmann, G W., 1990, Three-dimensional IP models; Investigations in
Geophysics
4--Induced Polarization, S ociety of Exploration Geophysicists.
TEM2D,
Solves 2-D Maxwell's equations in the time domain by the Dufort-Frankel
finite-difference method for the two-dimensional diffusion equation.
Sources of
excitation: current lines and vertical magnetic dipoles.
Current version by J. Adhidjaja (1985)
Original version by M. Oristaglio and G. Hohmann (1984)
Reference:
Adhidjaja, J.I., Hohmann, G.W., and Oristaglio, M.L., 1985,
Two-dimensional
transient electromagnetic responses: Geophysics, 50,
2849-2861.
EMWAVE,
Version 1.0, February 1996.
This code calculates full EM wave field
response of 3-D/2.5-D model by the FDTD method for the high frequency
range up
to 30 MHz. It permits spatial variations of sigma, epsilon and mu.
Transmitting
sources can be electric dipole(s) or magnetic dipole(s). The dipole(s)
can be
arbitrarily oriented and can be anywhere in the mesh, but not too close
to mesh
boundaries. The built-in source waveforms are (1) an
once-differentiated
Gaussian pulse and (2) a twice-differentiated Gaussian pulse. An option
is
provided to incorporate a user-supplied waveform.
Author: Tsili Wang
References:
T. Wang and A.C. Tripp, 1996, FDTD simulation of EM wave
propagation in 3-D media: Geophysics. 61, 110-120.
QLEM3D-1,
release March, 1998.
Three-dimensional EM forward modeling code
based on QL series. The code is based on quasi-linear-series (QL)
approximation
for the solution of the 3-D electromagnetic modeling problem which
improves the
accuracy by considering the QL approximations of the higher orders. The
code
generates the always converged QL series which makes it possible to
estimate
the accuracy of computations without direct comparison with the
rigorous full
integral equation (IE) solution.
Authors: Sheng Fang and Michael Zhdanov.
References:
Zhdanov, M. S., and Fang, S., 1997, Quasi linear series in 3D EM
modeling: Radio Science, 32, 6, 2167-2188.
GREENLIB,
release March, 1999.
A Fortran 77 library for computing the normal
fields and volume integrals of electromagnetic Green's tensors.
Computer
subroutines for calculating three-dimensional electromagnetic Green's
tensors
and the normal (primary) fields excited by different sources in a
frequency
range of 0-10,000,000 Hz. The following sources are considered: Plane
wave;
Horizontal electric bipole; Vertical electric bipole; Horizontal
rectangular
loop; Horizontal circular loop; Magnetic dipoles oriented in x, y and z
directions.
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.
Hursan, G., 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.
EMLAB
(Electromagnetic Matlab),
release March 2000.
Electromagnetic Matlab is an unified software
package for EM and potential fields modeling and inversion based on the
Matlab
Language of Technical Computing.
Authors: Gabor Hursan, Oleg Portniaguine, and Michael Zhdanov
GREEN3D,
release March 2000.
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.
INTEM3D,
release March 2001.
The Matlab software package for forward
modeling of a 3-D electromagnetic field, generated by plane wave and
different
types of controlled sources. This code is designed for simulating
frequency
domain EM responses of a three-dimensional (3-D) resistivity structure
in
horizontally layered earth using the integral equation method. The
package
includes forward modeling routines based on the Born approximation,
quasi-analytical approximation and series, full integral equation and
contraction integral equation methods.
The sources used in the program are the same
as in SYSEM and GREEN3D:
- 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.
Due to the advanced storage reduction and
FFT-based matrix multiplications, incorporated in this program, we can
obtain
full IE solutions for horizontally large models containing several
thousand
cells using iterative techniques. The options for calculating the Born,
and QA
approximations and series are designed for quick modeling of
excessively large
structures.
Authors: Gabor Hursan and Michael Zhdanov
References:
Zhdanov, M. S., Dmitriev, V. I., Fang, S., and G. Hursan, 2000,
Quasi-analytical approximations and series in electromagnetic modeling:
Geophysics, 65, 1746-1757.
Hursan, G., and M. S. Zhdanov, 2001, 3-D electromagnetic forward
modeling based
on the contraction integral equation method: Proceedings of 2001 CEMI
Annual
Meeting.
Hursan, G., 2001, Storage reduction and fast matrix multiplication for
integral-based geophysical problems: Proceedings of 2001 CEMI Annual
Meeting.
LQL3D,
release April 2002.
The LQL3D Matlab software package for forward
modeling of the 3-D electromagnetic field, generated by multiple
transmitters.
The package includesforward modeling routines based on the scalar
localized
quasi-linear (LQL) approximation, mean value localized quasi-linear
(MQL)
approximation, and tensorlocalized quasi-linear (TLQL) approximation
methods.
The Windows stand-alone executable of the program is provided along
with the
Matlab source codes.
Authors: Efthimios Tartaras, Ekaterina
Tolstaya, and Michael Zhdanov.
References:
Zhdanov, M. S., and E. Tartaras, 2002,
Inversion of multi-transmitter 3-D electromagnetic data based on the
localized
quasi-linear approximation: Geophys. J. Int., 148,
No. 3.
Tolstaya, E., Yoshioka, K., and M. S. Zhdanov, 2002,
Accuracy study of the quasi-analytical and quasi-linear
approximations for the 3-D electromagnetic field: Proceedings of the
CEMI 2002
Annual Meeting.
TIWLAC,
release April 2002.
The TIWLAC Matlab code for computing the
apparent conductivities in the anisotropic formations, based on
application of
the Newton method. The Windowsstand-alone executable of the program is
provided
along with the Matlab source codes.
Authors: Ertan Peksen and Michael Zhdanov
References:
Zhdanov, M. S., Kennedy, D., and E. Peksen,
2001, Foundations of tensor induction well-logging: Petrophysics,
42, No. 6, 588-610.
Zhdanov, M. S., Kennedy W. D., Cheryauka, B. A. and E. Peksen 2001,
Principles of tensor induction well logging in a
deviated well in an anisotropic medium: Transactions, 42nd SPWLA Annual
Logging
Symposium, Houston, paper R.
Peksen, E., and M. S. Zhdanov, 2002,
Apparent resistivity correction for tensor induction well logging in a
deviated well in
an anisotropic medium: Proceedings of the CEMI 2002 Annual Meeting.
PIE3D,
version 1.3, release March 2005.
Parallel EM forward modeling software based on the integral equation
(IE) method.
PIE3D 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 3-D anomalous
resistivity structures
in a horizontally layered earth.
The sources used in the program are the same as in INTEM3D:
- plane wave propagating vertically toward the earth (magnetotelluric);
- current bipoles along x, y and z directions;
- horizontal rectangular loop;
- horizontal circular loop;
- moving horizontal loops;
- magnetic dipoles oriented in x, y and z directions.
The code is based on the contraction integral equation method (Hursan
and Zhdanov 2002),
and it uses the complex generalized minimal residual method (Zhdanov,
2002)
to ensure the convergence of the iterative method of linear system of
equations.
The program exploits the FFT-convolution property of the EM integral
equations
and the horizontal invariance of the Green's tensors,
which reduces memory and CPU time in the modeling of horizontally large
structures.
The code is written in C, C++, FORTRAN, and MATLAB languages.
Authors: Ken Yoshioka and Michael Zhdanov.
References:
Hursan, G., and Zhdanov, M. S., 2002, Contraction integral equation
method
in three-dimensional electromagnetic modeling: Radio Sci., 37
(6), 1089,
doi: 10.1029/2001RS002513.
Yoshioka, K., and Zhdanov, M. S., 2005, Electromagnetic forward
modeling
based on the integral equation method using parallel computers:
Proc. Ann. Mtg., Consortium for Electromagnetic Modeling and inversion.
Zhdanov, M. S., 2002, Geophysical inverse theory and regularization
problems: Elsevier.
IBCEM3D,
release March 2005.
IBCEM3D is a Matlab software package for 3-D modeling of
electromagnetic field in the models with inhomogeneous background
conductivity. The code uses the contraction integral equation (CIE)
method of HursÑn and Zhdanov (2002) as a main algorithm for the
solution of the corresponding EM field integral equations. IBCEM3D can
be used for modeling the EM field generated by different sources in
complex 3-D geoelectrical structures. The sources used in the program
are the same as in 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.
The program is written in the Matlab language, but it can also be run
without Matlab. The Windows stand-alone executable of the program is
provided along with the Matlab source codes.
Authors: Seong Kon Lee and Michael Zhdanov.
References:
Hursan, G., and Zhdanov, M. S., 2002, Contraction integral equation
method
in three-dimensional electromagnetic modeling: Radio Sci., 37
(6),
1089, doi: 10.1029/2001RS002513.
Lee, S. K., and Zhdanov, M. S., 2005, Integral equation method for 3-D
modeling of electromagnetic fields in complex structures with
inhomogeneous background conductivity: Proc. Ann. Mtg., Consortium for
Electromagnetic Modeling and inversion.
Zhdanov, M. S., 2002, Geophysical inverse theory and regularization
problems: Elsevier.
PIE3D,
version 2.3a, release March 2006.
Parallel EM forward modeling software based on the integral equation
(IE) method.
PIE3D 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 3-D anomalous
resistivity structures
in a horizontally layered anisotropic media.
PIE3D 2.3a also supports the anisotropic anomalous conductivity
in the case that principal axis of the anomalous conductivity tensor
coincides
ith the axis of the Cartesian coordinate system.
The sources used in the program are the same as in INTEM3D and in
PIE3D, version 1.3.
The code is based on the contraction integral equation method (CIE),
and it uses the complex generalized minimal residual method (CGMRM)
to ensure the convergence of the iterative method of linear system of
equations.
The program exploits the effective FFT-convolution property of the EM
integral equations
and the horizontal invariance of the Green's tensors,
which reduces memory and CPU time in the modeling of horizontally large
structures.
The code is written in C, C++, FORTRAN, and MATLAB languages, and
requires GREEN3DA library.
Authors: Ken Yoshioka and Michael Zhdanov.
References:
Hursan, G., and Zhdanov, M. S., 2002, Contraction integral equation
method
in three-dimensional electromagnetic modeling: Radio Sci.,37
(6), 1089,
doi: 10.1029/2001RS002513.
Yoshioka, K., and Zhdanov, M. S., 2005, Electromagnetic forward
modeling
based on the integral equation method using parallel computers:
Proc. Ann. Mtg., Consortium for Electromagnetic Modeling and inversion.
Zhdanov, M. S., 2002, Geophysical inverse theory and regularization
problems: Elsevier.
GREEN3DA,
release March 2006.
The computer library for computing the normal fields and volume
integrals of
electromagnetic Green's tensors in layered stratified anisotropic
medium.
This provides MATLAB MEX (dynamically linked subroutines) files,
static, and shared libraries. This program is designed to help the
development of electromagnetic modeling and inversion programs.
It is an easy-to-use Green's tensors function which can be called up
anywhere
in the MATLAB, C, C++, and FORTRAN environments.
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
stratified anisotropic medium.
The code is written in C, and FORTRAN.
Author: Ken Yoshioka and Michael Zhdanov
References:
Hursan, G., 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.
Xiong, Z., 1992, EM modeling of three-dimensional structures
by the method of system iteration using integral equations,
Geophysics, 57, 1556-1561.
Yoshioka, K., and Zhdanov, M. S., 2006, Parallel implementation of the
integral equation method
for 3-D electromagnetic modeling in anisotropic media: Proc. Ann. Mtg.,
Consortium for Electromagnetic Modeling and inversion, 49-80.
Zhdanov, M. S., and G. V. Keller, 1994, The geoelectrical methods in
geophysical exploration: Elsevier, 873 pp.
INTEM3DQL,
release March 2006.
The Matlab software package for forward modeling of a 3-D
electromagnetic field
based on the INTEM3D, generated by plane wave and different types of
controlled sources.
This code is designed for simulating frequency domain EM responses
of a three-dimensional (3-D) resistivity structure in horizontally
layered earth using the integral equation method.
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 multi-grid quasi-linear (MGQA) approximation. The sources
used in the program are the same as in SYSEM, GREEN3D and INTEM3D.
Authors: Takumi Ueda and Michael Zhdanov
References:
Zhdanov, M. S., Dmitriev, V. I., Fang, S., and G. Hursan, 2000,
Quasi-analytical approximations and series in electromagnetic modeling:
Geophysics, 65, 1746-1757.
Hursan, G., and M. S. Zhdanov, 2001, 3-D electromagnetic forward
modeling
based on the contraction integral equation method: Proceedings of 2001
CEMI Annual Meeting.
Hursan, G., 2001, Storage reduction and fast matrix multiplication
for integral-based geophysical problems: Proceedings of 2001 CEMI
Annual Meeting.
Ueda, T., and M. S. Zhdanov, 2005, Fast numerical modeling of
marine controlled-source electromagnetic data using quasi-linear
approx-imation,
75th Ann. Internat. Mtg., Soc. Expl. Geophys., Expanded Abstracts.
Ueda, T., and M. S. Zhdanov, 2006, Multi-grid quasi-linear
approximation
in SBL modeling, Proceedings of 2006 CEMI Annual Meeting, 143-158.
PIE3D 2.4 IBC,
release March 2007. Parallel EM forward modeling software based on the
integral equation (IE) method. PIE3D 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 3-D anomalous resistivity structures in a
horizontally layered anisotropic media. PIE3D 2.4 IBC also supports
inhomogeneous background conductivity modeling to determine EM response
from multiple domains. Principal use of IBC is in including bathymetry
or terrain effects in the EM modeling.
The sources used in the program are the same as in INTEM3D:
- plane wave propagating vertically toward the earth (magnetotelluric);
- current bipoles along x, y, and z directions;
- horizontal rectangular loop;
- horizontal circular loop;
- moving horizontal loops;
- electric dipoles oriented in x, y, and z directions;
- magnetic dipoles oriented in x, y, and z directions.
The code is based on the contraction integral equation method (CIE),
and it uses the complex generalized minimal residual method (CGMRM) to
ensure the convergence of the iterative method of linear system of
equations. The program exploits the effective FFT-convolution property
of the EM integral equations and the horizontal invariance of the
Green's tensors, which reduces memory and CPU time in the modeling of
horizontally large structures. The code is written in C, C++, FORTRAN,
and MATLAB languages, and requires the GREEN3DA library.
Authors: Ken Yoshioka, Martin Cuma and Michael S. Zhdanov.
References:
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.
Yoshioka, K., and M. S. Zhdanov, 2005, Electromagnetic forward
modeling based on the integral equation method using parallel
computers: Proc. Ann. Mtg., 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: Proc. Ann. Mtg., 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.
Zhdanov, M. S., 2002, Geophysical inverse theory and regularization
problems: Elsevier.
INTEM3DQLT,
release March 2007. The Matlab software package for 3-D modeling of
electromagnetic field in the models. The code uses the contraction
integral equation (CIE)
method for the solution of the frequency domain EM field integral
equations, and uses digital filter to transform the frequency domain
responses to the time domain responses. INTEM3DQLT can be used for
modeling the frequency and time domain EM fiels generated by different
sources in complex 3-D geoelectrical structures. 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
References:
Endo, M., and M. S. Zhdanov, 2007, Three-dimensional modeling of
transient electromagnetic fields based on integral equation method:
Proceedings of 2007 CEMI Annual Meeting.
IBCEM3DT,
release March 2007. The Matlab software package for 3-D modeling of
electromagnetic field in the models with inhomogeneous background
conductivity. The code uses the contraction integral equation (CIE)
method for the solution of the frequency domain EM field integral
equations, and uses digital filter to transform the frequency domain
responses to the time domain responses. IBCEM3DT can be used for
modeling the frequency and time domain EM fiels generated by different
sources in complex 3-D geoelectrical structures. The sources used in
the program are the same as in IBCEM3D:
- 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
References:
Endo, M., and M. S. Zhdanov, 2007, Three-dimensional modeling of
transient electromagnetic fields based on integral equation method:
Proceedings of 2007 CEMI Annual Meeting.
Lee, S. K., and M. S. Zhdanov, 2005, Integral equation method for 3-D
modeling of electromagnetic fields in complex structures with
inhomogeneous background conductivity: Proceedings of 2005 CEMI 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.
GREEN3DA_2,
release March 2008.
The computer library for computing the normal fields and volume
integrals of
electromagnetic Green's tensors in layered stratified anisotropic
medium in double precision.
This code is provided as a Matlab code and as MATLAB MEX (dynamically
linked subroutines) files. This program is designed to help the
development of electromagnetic modeling and inversion programs.The
sources used in
the program are the same as in GREEN3DA:
- 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.
Author: Masashi Endo, Martin Cuma, Ken Yoshioka, and Michael Zhdanov
References:
Hursan, G., 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.
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.
Zhdanov, M. S., 2002, Geophysical inverse theory and regularization
problems: Elsevier.
PIE3D 2.5 IBC_MGQL,
release March 2008. Parallel EM forward modeling software based on the
integral equation (IE) method. PIE3D 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 3-D anomalous resistivity structures in a
horizontally layered anisotropic media. A new feature in this release
is use of multigrid quasi-linear (MGQL) approximation to speed up the
caluclation at a minimal compromise in accuracy. The MGQL method uses
larger cell sizes to calculate anomalous fields in domains of interest
and maps them to a finer grid, using the quasi-linear approximation.
PIE3D 2.5 IBC_MGQL code also supports
inhomogeneous background conductivity modeling to determine EM response
from multiple domains. The principal use of IBC is in including
bathymetry
or terrain effects in the EM modeling.
The sources used in the program are the same as in INTEM3D:
- plane wave propagating vertically toward the earth (magnetotelluric);
- current bipoles along x, y, and z directions;
- horizontal rectangular loop;
- horizontal circular loop;
- moving horizontal loops;
- electric dipoles oriented in x, y, and z directions;
- magnetic dipoles oriented in x, y, and z directions.
The code is based on the contraction integral equation method (CIE),
and it uses the complex generalized minimal residual method (CGMRM) to
ensure the convergence of the iterative method of linear system of
equations. The program exploits the effective FFT-convolution property
of the EM integral equations and the horizontal invariance of the
Green's tensors, which reduces memory and CPU time in the modeling of
horizontally large structures. The code is written in C, C++, FORTRAN,
and MATLAB languages, and uses the GREEN3DA_2 double precision library.
Authors: Martin Cuma, Ken Yoshioka, and Michael S. Zhdanov.
References:
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.
Yoshioka, K., and M. S. Zhdanov, 2005, Electromagnetic forward
modeling based on the integral equation method using parallel
computers: Proc. Ann. Mtg., 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: Proc. Ann. Mtg., 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 electromagneitc 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.
INTEM3DQLT_2,
release March 2008. The Matlab software package for forward modeling of
a 3D electromagnetic field based on the INTEM3DQL, generated by plane
wave and different types of controlled sources. The code is designed
for simulating both time and frequency domain EM responses of a 3D
resistivity structure in horizontally layered earth. This code computes
frequency domain responses using integral equation (IE) method in
double precision. The responses are then transformed to time domain
responses in double precision by a digital filtering technique. The
sources used in
the program are the same as in GREEN3DA_2:
- 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
References:
Ueda, T., and M. S. Zhdanov, 2006, Multigrid quasi-linear approximation
in SBL modeling: Proceedings of 2006 CEMI Annual Meeting.
Endo, M., and M. S. Zhdanov, 2007, Three-dimensional modeling of
transient electromagnetic fields based on integral equation method:
Proceedings of 2007 CEMI Annual Meeting.
IBCEM3DT_2,
release March 2008. The Matlab software package for 3-D modeling of
electromagnetic field in the models with inhomogeneous background
conductivity. The code uses the contraction integral equation (CIE)
method for the solution of the frequency domain EM field integral
equations, and uses digital filter to transform the frequency domain
responses to the time domain responses. IBCEM3DT_2 can be used for
modeling the frequency and time domain EM fiels generated by different
sources in complex 3-D geoelectrical structures. The responses in both
time and frequency domains are computed in double precision. The
sources used in
the program are the same as in GREEN3DA_2:
- 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
References:
Lee, S. K., and M. S. Zhdanov, 2005, Integral equation method for 3-D
modeling of electromagnetic fields in complex structures with
inhomogeneous background conductivity: Proceedings of 2005 CEMI Annual
Meeting.
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.
Endo, M., and M. S. Zhdanov, 2007, Three-dimensional modeling of
transient electromagnetic fields based on integral equation method:
Proceedings of 2007 CEMI Annual Meeting.
IP2DI,
Finite element program for simulation and parameterized inversion of
dipole-dipole resistivity/IP responses over arbitrarily complex 2-D
cross-sections including topography. High accuracy of the integral
transform
over the spatial wavenumber along strike has been achieved by
exploiting the
logarithmic and exponential asymptotic behavior of the voltage kernel.
The IP
effect and the Jacobians of model resistivity are obtained with
negligible
effort by exploiting reciprocity.
Author: P.E. Wannamaker
Reference: Wannamaker, P. E., IP2DI-v1.00, 1992, Finite element program
for
dipole-dipole resistivity/IP forward modeling and parameterized
inversion of
two-dimensional earth resistivity structure, Univ. of Utah Research
Inst. Rept.
ESL-92002-TR, 40 pp.
DD2D,
release from 21 October 1994.
This program inverts apparent resistivity and IP data. First, apparent
resistivity data are iteratively inverted, then polarizabilities are
inverted
in one step. Parameters inverted for are : row resistivities(rhoy), IP
parameters (phiy). Contains 'padding cells' on left and right sides of
grid for
greater flexibility.
Author: Les P. Beard January,1993. Last modified: 21 Oct 94
Reference: Beard, L.P., 1994, PhD dissertation, university of Utah.
INVGRVS and INVGRVSD,
version 1.3, August 16, 1991.
Cooperative inversion technique for 2D gravity and TEM data. The
program
inverts gravity data for depth using a minimum-structure, least-squares
algorithm. Where TEM depth constrains exist, density contrasts are
adjusted to
create gravity model depths that agree with the TEM model depths. The
forward
algorithm is provided by Dobrin (1976). The valley(alluvium) is divided
up into
vertically elongated, parallel sided prisms. The sensitivity matrix is
composed
of the Frechet Derivative as the parameter derivatives.
Author: Hans J. Rasmussen
PAREST1,
Least-Squares Inversion Driver Routine. The program is designed for
least-squares data
fitting using arbitrary forward modeling codes. PAREST solves inverse
problems
for broad variety of applications, in particular, coupled with forward
code
SYSEM it solves 3-D electromagnetic inverse problem. The user has to
run PAREST
together with the forward modeling code which simulates the desired
type of data.
The forward code itself can be used without any modifications. The user
has to
define free parameters which will be changed to fit the observed data.
Starting
from initial guess, PAREST iteratively updates input parameters fitting
the
data in a least-squares sense.
Authors: O. Portniaguine, M. S. Zhdanov
References:
Portniaguine, O. and M.S. Zhdanov, 1995, Parameter Estimation
Method in the solution of 3D geoelectromagnetic inverse problems, 3-D
electromagnetics, Proceedings of the International Symposium,
Schlumberger-Doll
Research, Ridgefield, CT.
Portniaguine, O., Zhdanov, M. S., 1999, Parameter estimation for 3D
geoelectromagnetic inverse problems: Three Dimensional
Electromagnetics, SEG
Monograph, 222-232.
MTINV2D,
Two-dimensional forward modeling and
regularized inversion of magnetotelluric data. The forward modeling
subroutine
is based on a finite-difference scheme. The inversion can be done for
TE, TM,
or both TE and TM apparent resistivities and phases at receivers on the
surface. The model parameters are the conductivities of each
finite-difference
cell.
Authors: Patricia de Lugao, Oleg Portniaguine and Michael Zhdanov
References: Zhdanov, M.S., de Lugao, P.P., and Portniaguine, O., 1995,
Two-dimensional regularized inversion of magnetotelluric data, SEG
International Exposition and 65th Annual Meeting, Houston, TX, October
8-13,
1995, Expanded Abstracts with Author's Biographies, 803-806.
MTINV2D-2W
(version 2 with weighting), release March, 1998.
Two-dimensional forward modeling and
regularized weighting inversion of MT and CSMT data. We introduced
different
improvements in the 2-D plane electromagnetic inversion code developed
by
Patricia de Lugao in 1997. The most significant improvement is based on
introducing weights in geoelectrical model parameters, which
accelerates the
convergence of the iterative inversion scheme and increases the
resolution of
inverse method. In addition, we optimize the step of the conjugate
gradient
iterations and significantly minimize the time required for solving the
linear
system of equations arising from the forward problem (7-10 times
faster) by
optimizing the code.
Authors: Patricia de Lugao, Salah Mehanee, Nikolay Golubev, and Michael
Zhdanov.
References:
de Lugao, P., and Zhdanov, M., 1997, Fast and stable
two-dimensional inversion of magnetotelluric data: CEMI 1997 Annual
Report.
Mehanee, S., Golubev, N., and Zhdanov, M., 1998, Improved Regularized
Inversion
of Magnetotelluric Data: CEMI 1998 Annual Report.
3DEMVISUAL
, release March, 1998.
Three-dimensional electromagnetic forward
modeling, inversion and visualization software package based on MATLAB
language.
The Matlab software 3DEMVISUAL is designed to visualize the results of
3-D
forward modeling and inversion based on integral equation methods and
QL
approximations. It generates volume images of the forward modeling and
inversion results for 3-D geoelectrical structures.
Authors: Sheng Fang and Michael Zhdanov.
References:
Zhdanov, M. S, and Fang, S., 1996, Quasi-linear approximation in
3-D EM modeling: Geophysics, 61, vol 3, 646-665.
Zhdanov, M. S, and Fang, S., 1996, 3-D quasi-linear electromagnetic
inversion:
Radio Science, 31, vol 4, 741-754.
Zhdanov, M. S. and Fang, S., 1997, Quasi linear series in 3D EM
modeling:
Radio Science, 32, vol 6, 2167-2188.
MTINVMS
, release March, 1999.
Magnetotelluric inversion with the minimum
support stabilizing functional. Two-dimensional regularized weighting
inversion
of MT and CSMT data with the minimum support stabilizing functional.
The new
code is based on the ideas of focusing geophysical images (Portniaguine
and
Zhdanov, 1999) to generate a focused and resolved MT inverse image. The
code
uses as the basic platform the original code MTINV2D developed in 1997
by de
Lugao and Zhdanov (1997).
Authors: Salah Mehanee and Michael Zhdanov.
References:
de Lugao, P., and M. S. Zhdanov, 1997, Fast and stable two-dimensional
inversion of magnetotelluric data: CEMI 1997 Annual Report.
De Lugao, P., Portniaguine, O., and M.S. Zhdanov, 1997, Fast and stable
two-dimensional inversion of magnetotelluric data: J. Geomag.
Geoelectr.,
49, 1469-1497.
Portniaguine, O., and M. S. Zhdanov, 1999, Focusing Geophysical
Inversion
Images: Geophysics, in press.
Mehanee, S., and M. S. Zhdanov, 1999, Magnetotelluric Inversion of
Blocky
Geoelectrical Structures Using Minimum Support Method: Proceedings of
the CEMI
1999 Annual Meeting.
GRAV3D,
release March 1999.
A three-dimensional inversion of gravity data
based on the focusing imaging method. The computer code uses the ideas
of
focusing inversion and compression to solve 3-D gravity inverse
problem. With
compression, we achieve a great reduction in speed and memory
requirements for
3-D gravity data inversion.
Authors: Oleg Portniaguine and Michael Zhdanov.
References:
Portniaguine, O., and M. S. Zhdanov, 1999, Focusing Geophysical
Inversion
Images: Geophysics, 64, 874-887.
Portniaguine, O., and M. S. Zhdanov, 1999, Compression in Inverse
Problem
Solution: Proceedings of CEMI 1999 Annual Meeting.
QLINV3D2,
release March 1999. Three-dimensional EM inversion code based on QL
approximation.
The code is based on quasi-linear (QL) approximation of forward
modeling operator.
It generates a linear equation with respect to the modified
conductivity tensor
which is proportional to the reflectivity tensor and the complex
anomalous conductivity.
This linear equation is solved by using regularized conjugate gradient
method.
After determining a modified conductivity tensor the code uses
the electrical reflectivity tensor to evaluate the anomalous
conductivity.
The code can be applied for 3-D inversion of magnetotelluric, CSMT,
frequency domain surface, borehole, and airborne EM data for arbitrary
transmitter-receiver arrays.
Authors: Sheng Fang and Michael Zhdanov.
References:
Zhdanov, M. S., and Fang, S., 1996, 3-D quasi-linear electromagnetic
inversion:
Radio Science, 31, No. 4, 741-754.
Golubev, N., Zhdanov, M. S., and K. Matsuo, 1999,
Inversion of Three-dimensional Magnetotelluric Data Collected
for Hydrocarbon Exploration in the Overthrust Area in Japan:
Proceedings of CEMI 1999 Annual Meeting.
MTINV-MSJ,
release March 2000.
The two-dimensional regularized focusing
inversion Fortran code for joint inversion of TE & TM mode MT and
CSMT
data. The new code is based on the idea of focusing geophysical images
to
generate a focused and resolved MT inverse image. The code uses as its
basic
platform the original code MTINV2D developed in 1997 by de Lugao and
Zhdanov.
Authors: Salah Mehanee and Michael Zhdanov
References:
de Lugao, P., and M.S. Zhdanov, 1997, Fast and stable two-dimensional
inversion
of magnetotelluric data: CEMI 1997 Annual Report.
De Lugao, P., Portniaguine, O., and M.S. Zhdanov, 1997, Fast and stable
two-dimensional inversion of magnetotelluric data: J. Geomag.
Geoelectr.,
49, 1469-1497.
Portniaguine, O. and Zhdanov, M.S, 1999, Focusing geophysical inversion
images:
Geophysics, 64, 874-887.
CSMT3D,
version 1.4, release March 2001.
The computer code for 3-D inversion of MT and
CSMT data with model compression and image focusing. This program
converts the
apparent resistivity data measured on an irregular grid to a volume
resistivity
image. The simple graphical utilities built into the code allow the
user to
view the observed and predicted data, and interactively view estimated
anomalous currents and the resulting 3-D resistivity image. Version 1.5
of the
program can be run in two modes: a) under a Matlab environment, or b)
as a stand-alone
application. The program is released ''ready to use'' on PC under
Microsoft
Windows.
Authors: Oleg Portniaguine and Michael Zhdanov
References: Portniaguine, O., and M. S. Zhdanov, 1999, Focusing
geophysical inversion
images: Geophysics, 64, 874-887
Portniaguine, O., and M. S. Zhdanov, 1999, Compression in inverse
problem
solution: Proceedings of CEMI 1999 Annual Meeting.
Portniaguine O., and M. S. Zhdanov, 1999, 3-D focusing inversion of
CSMT data:
Second International Symposium of Three-Dimensional Electromagnetics,
Utah,
132-135.
LOCSINV,
release April 2002.
The software package for the localized
S-inversion of the time domain electromagnetic data. This technique
is based on
the traditional thin sheet approach, but it provides a more adequate
geoelectrical image of geological cross-sections by allowing for
lateral
variations in conductivity. The program is written in standard C/C++
language.
Authors: Dmitriy Pavlov and Michael Zhdanov.
References:
Tartaras, E., Zhdanov, M. S., Wada, K., Saito, A., and T. Hara, 2000,
Fast imaging of TDEM data based on S-inversion:
Journal of Applied Geophysics, 43, No. 1, 15-32.
Zhdanov, M. S., Pavlov, D., and R. Ellis, 2002,
Localized S-inversion of the time domain electromagnetic data:
Geophysics, in press.
Zhdanov, M. S., Pavlov, D., and R. Ellis, 2002, TDEM data
interpretation based on
localized S-inversion: Proceedings of the CEMI 2002 Annual Meeting.
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.
QAINV3D,
version 3.0, release March 2004.
The Matlab software package for 3-D inversion of array magnetotelluric
data based
on quasi-analytical approximation of the forward modeling operator.
The new version of the program combines the advantages of the rigorous
and approximate methods. As a main engine of inversion algorithm,
we use the quasi-analytical (QA) approximation of the forward modeling
operator.
However, at the final stage of inversion, we apply the rigorous forward
modeling method
to confirm the accuracy of our inversion result.
This approach ensures the speed and efficiency of 3-D magnetotelluric
inversion.
The program is written in the Matlab language, but it can also be run
without Matlab.
The Windows stand-alone executable of the program is provided along
with the Matlab source codes.
The program is provided also with the user friendly GUI for input
parameters
and a convenient visualization tool to represent the volume image
and the arbitrarily selective cross-sections and depth-slices
of the inverse conductivity model.
The visualization software is included as a subroutine,
which can be applied to the inversion results.
This visualization subroutine reads the inversion results
and generates the 2-D and 3-D conductivity images easily.
Authors of the original version: Gabor Hursan and Michael S. Zhdanov.
Modifications by Nikolay Golubev and Michael S. Zhdanov.
References:
Zhdanov, M. S., Dmitriev, V. I., Fang, S., and G. Hursan, 2000,
Quasi-analytical approximations and series in electromagnetic modeling,
Geophysics, 65, 1746-1757.
Golubev, N., and M. S. Zhdanov, 2003,
3-D Magnetotelluric Inversion Over Complex Geological Structures:
Proceedings of the CEMI 2003 AnnualMeeting.
Zhdanov, M. S., 2002, Geophysical inverse theory and regularization
problems: Elsevier.
GRMAG3D
, version 3.0.
The computer code for
three-dimensional inversion of gravity, magnetic, and
gravity gradient data with image focusing.
The current version can process the gravity gradient data with an
option for joint inversion of
the different gravity tensor components. The code is based on
implementation
of a focusing stabilizer for regularized inversion of potential field
data.
The focusing inversion makes its possible to reconstruct a much more
focused
and clear image of the geological target than conventional maximum
smoothness inversion.
Authors: Oleg Portniaguine, Gabor Hursan, Souvik Mukherjee, and Michael
S. Zhdanov.
References: Portniaguine, O., and M. S. Zhdanov, 1999, Focusing
geophysical inversion
images: Geophysics, 64, 874-887.
Portniaguine O., and M. S. Zhdanov, 2002, 3-D magnetic inversion with
data
compression and image focusing: Geophysics, 67, No.
5, 1532-1541.
Zhdanov, M. S. Ellis, R. G., Mukherjee, S., and D. Pavlov, 2002,
Regularized
focusing inversion of 3-D gravity tensor data:72-nd SEG Annual Meeting,
Expanded Abstracts, Salt Lake City, 751-754.
Zhdanov, M. S., 2002, Geophysical inverse theory and regularization
problems: Elsevier, Amsterdam - New York - Tokyo, 609 pp.
GRMAG3DTOPO,
release March 2005.
GRMAG3DTOPO is a Matlab software package for three-dimensional (3-D)
inversion of magnetic, gravity, and gravity gradient data collected on
any arbitrary surface of observation. The code is designed for 3-D
focusing inversion of the vertical component of gravity data, any
component of the anomalous magnetic field, including a total magnetic
anomaly, and any component of the gravity gradient tensor with an
option for joint inversion of the different gravity tensor components.
The program is written in the Matlab language, but it can also be run
without Matlab. The Windows stand-alone executable of the program is
provided along with the Matlab source codes.
The GRMAG3DTOPO code is provided with a GEOSOFT Oasis montaj interface.
During execution, the applications read database files from Oasis
montaj and convert them to the ASCII format, which can be read by
GRMAG3DTOPO software. The results of GRMAG3DTOPO code computations are
then converted to the Geosoft format and can be exported back to Oasis
montaj, or can be visualized by any other geophysical visualization
software.
Authors: Michael Jessop and Michael S. Zhdanov.
References:
Zhdanov, M. S., 2002, Geophysical inverse theory and regularization
problems: Elsevier.
Zhdanov, M. S., Ellis, R. G., and Mukherjee, S., 2004,
Regularized focusing inversion of 3-D gravity tensor data: Geophysics, 69,
925-937.
Jessop, M., and Zhdanov, M. S., 2005, Focusing inversion of gravity
gradient data
collected on an arbitrary observation surface: Proc. Ann. Mtg.,
Consortium for Electromagnetic Modeling and inversion.
LQLInv3DTOPO,
release March 2005.
LQLInv3DTOPO is a Matlab software package for inversion of
three-dimensional (3-D) frequency domain helicopter electromagnetic
(HEM) data based on the localized quasi-linear (LQL) approximation,
with the terrain or bathymetry corrections. The code has two options
for rigorous and approximate (fast) terrain correction. It takes into
account the distortion caused by a variable earth-air interface, and
compensates for the topography effects or bathymetry effects. The new
code LQLInv3DTOPO has two different inversion subroutines, based on the
re-weighted regularized conjugate gradient (RRCG) algorithm, and the
spectral Lanczos decomposition (SLDM) algorithm, respectively. In both
subroutines, it is possible to enforce either smooth or sharp
constraints on the model. The program is written in the Matlab
language, but it can also be run without Matlab. The Windows
stand-alone executable of the program is provided along with the Matlab
source codes.
The LQLInv3DTOPO code is provided with the GEOSOFT Oasis montaj
interface. During execution, the applications read database files from
Oasis montaj and convert them to the ASCII format, which can be read by
LQLInv3DTOPO software. The results of the LQLInv3DTOPO code
computations are then converted to the Geosoft format and can be
exported back to Oasis montaj, or can be visualized by any other
geophysical visualization software.
Authors: Hiroyuki Katayama, Leif Cox and Michael S. Zhdanov.
References:
Zhdanov, M. S., 2002, Geophysical inverse theory and regularization
problems: Elsevier.
Zhdanov, M. S., and Tartaras, E., 2002, Inversion of multi-transmitter
3-D electromagnetic data
based on the localized quasi-linear approximation: Geophys. J. Int., 148,
506-519.
Zhdanov, M. S., and Chernyavskiy, A, 2004, Rapid three-dimensional
inversion of multi-transmitter
electromagnetic data using the spectral Lanczos decomposition method:
Inverse Problems, 20, S233-S256.
Katayama, H., and Zhdanov, M. S., 2004, 3-D Inversion of
helicopter-borne EM data
in areas with rough topography:
Proc. Ann. Mtg., Consortium for Electromagnetic Modeling and inversion,
177-212.
Cox, L. H., and Zhdanov, M. S., 2005, Numerical study of the
helicopter-borne electromagnetic (HEM)
response of kimberlite pipes: Proc. Ann. Mtg., Consortium for
Electromagnetic Modeling and inversion.
LQLRigInvTOPO,
release March 2006.
LQLRigInvTOPO is a Matlab software package for inversion of
three-dimensional (3-D) frequency domain helicopter electromagnetic
(HEM) with terrain or bathymetry corrections.
The code is base on the localized quasi-linear (LQL) approximation in
the initial stages to get an approximate image.
The results are checked with rigorous forward modeling and the
inversion can continue with rigorous inversion if necessary..
The code has two options for rigorous and approximate (fast) terrain
correction.
It takes into account the distortion caused by a variable earth-air
interface,
and compensates for the topography effects or bathymetry effects.
All of these effects are included in the rigorous portion of the code.
The new code LQLRigInvTOPO has two different inversion subroutines,
based on the re-weighted regularized conjugate gradient (RRCG)
algorithm,
and the spectral Lanczos decomposition (SLDM) algorithm, respectively.
In both subroutines, it is possible to enforce either smooth or sharp
constraints on the model.
Logarithmic bounds are also enforced during the rigorous stages
to constrain the results within user defined reasonable geologic
bounds.
The program is written in the Matlab language, but it can also be run
without Matlab.
The Windows stand-alone executable of the program is provided along
with the Matlab source codes.
The LQLRigInvTOPO code is provided with the GEOSOFT Oasis montaj
interface.
During execution, the applications read database files
from Oasis montaj and convert them to the ASCII format,
which can be read by LQLRigInvTOPO software.
The results of the LQLRigInvTOPO code computations are then converted
to the Geosoft format and can be exported back to Oasis montaj, or can
be visualized by any other geophysical visualization software.
Authors: Leif H. Cox, Hiroyuki Katayama, and Michael S. Zhdanov.
References:
Zhdanov, M. S., 2002, Geophysical inverse theory and regularization
problems: Elsevier.
Zhdanov, M. S., and Tartaras, E., 2002, Inversion of multi-transmitter
3-D electromagnetic data based on the localized quasi-linear
approximation:
Geophys. J. Int., 148, 506-519.
Zhdanov, M. S., and Chernyavskiy, A, 2004, Rapid three-dimensional
inversion
of multi-transmitter electromagnetic data using the spectral Lanczos
decomposition method:
Inverse Problems, 20, S233-S256.
Katayama, H., and Zhdanov, M. S., 2004, 3-D Inversion of
helicopter-borne EM data
in areas with rough topography: Proc. Ann. Mtg.,
Consortium for Electromagnetic Modeling and Inversion, 177-212.
Cox, L. H., and Zhdanov, M. S., 2005, Numerical study of
the helicopter-borne electromagnetic (HEM) response of kimberlite
pipes:
Proc. Ann. Mtg., Consortium for Electromagnetic Modeling and Inversion.
Cox, L. H. and Zhdanov, M. S., 2006, Rapid and rigorous 3-D inversion
of the airborne electromagnetic data: Proc. Ann. Mtg.,
Consortium for Electromagnetic Modeling and Inversion, 103-120.
FD_AEMInv,
release March 2007. FD_AEMInv ( Frequency Domain Airborne
Electromagnetic Inversion) is a program used to invert multi-frequency,
multi-component, frequency domain airborne electromagnetic data. It is
a realization of the 3D airborne inversion algorithms developed at the
Consortium for Electromagnetic Modeling and Inversion. This code
includes the localized quasi-linear (LQL) approximate inversion
algorithm (Zhdanov and Tartaras, 2002) and a rigorous inversion
algorithm (Cox and Zhdanov, 2007a). Both algorithms utilize the moving
footprint inversion method (Cox and Zhdanov, 2007b). This method allows
for large scale airborne data inversions on a single PC. Using the
approximate inversion method in conjunction with the moving footprint
method, up to 50,000 data points have been inverted using inversion
domains of 40km^2 discretized into one millions cells. The rigorous
inversion method is significantly slower, but provides full integral
equation accuracy and can handle hundreds of thousands of cells in the
inversion domain and thousands of transmitter-receiver pairs. The large
scale inversions will typically run in one day or less on a single PC.
The code is designed with a graphical user interface (GUI) to simplify
the input of survey and inversion parameters. The GUI can either be
used to format the inversion parameters and execute the inversion code,
or it can be used to format input files and the inversion code can then
be run remotely from the command line. The GUI has been compiled into a
stand alone windows executable. It also can be run in its native
language, MatLab.
Leif H. Cox and Michael S. Zhdanov
References:
Cox, L. H., and M. S. Zhdanov, 2007a, Advances in rapid and rigorous
inversion of 3D AEM data: Proceedings from the Annual Meeting of the
Consortium for Electromagnetic Modeling and Inversion.
Cox, L. H., and M. S. Zhdanov, 2007b, Large Scale approximate 3D
inversion of HEM data using a moving footprint: Proceeding from the
Annual Meeting of the Consortium for Electromagnetic Modeling and
Inversion.
Liu, G., and A. Becker, 1990, Two-dimensional mapping of sea-ice keels
with airborne electromagnetics: Geophysics, 55, 239-248.
Portniaguine O., and M. S. Zhdanov, 2002, 3-D magnetic inversion with
data compression and image focusing: Geophysics, 67, 1532-1541.
Reid, J. E., A. Pfaffling, and J. Vrbancich, 2006, Airborne
electromagnetic footprints in 1D Earths: Geophysics, 71, G63-G72.
Zhdanov, M. S., and E. Tartaras, 2002, Inversion of multi-transmitter
3-D electromagnetic data based on the localized quasi-linear
approximation: Geophysical Journal International, 148, 506-519.
Zhdanov, M. S., 2002, Geophysical inverse theory and regularization
problems: Elsevier.
FD_AEMInvTOPO,
release March 2008. FD_AEMInvTOPO (Frequency
Domain Airborne
Electromagnetic Inversion with the terrain or
bathymetry corrections) is a program used to invert multi-frequency,
multi-component, frequency domain airborne electromagnetic data. It is
a realization of the 3D airborne inversion algorithms developed at the
Consortium for Electromagnetic Modeling and Inversion. This code
includes the localized quasi-linear (LQL) approximate inversion
algorithm (Zhdanov and Tartaras, 2002) and a rigorous inversion
algorithm (Cox and Zhdanov, 2008a). Both algorithms utilize the moving
footprint inversion method (Cox and Zhdanov, 2007). This method allows
for large scale airborne data inversions on a single PC. Using the
approximate inversion method in conjunction with the moving footprint
method, up to 50,000 data points have been inverted using inversion
domains of 40km^2 discretized into one millions cells. The rigorous
inversion method is significantly slower, but provides full integral
equation accuracy and can handle hundreds of thousands of cells in the
inversion domain and thousands of transmitter-receiver pairs. The large
scale inversions will typically run in one day or less on a single PC.
The new release also includes a modified integral equation formulation
which can accurately calculate the magnetic field response from areas
with rough topography. This allows inclusion of topography into the
inversion domain. The inversion with topographic correction applies to
both the LQL inversion and the rigorous inversion scheme. The
approximate inversion method includes coupling from the terrain to the
anomalous geology, but not the reverse. The rigorous inversion method
includes all coupling to utilize the full accuracy of the integral
equation method. This method has been tested on both synthetic and
field data, both with excellent results (Cox and Zhdanov, 2008b). The
code is designed with a graphical user interface (GUI) to simplify
the input of survey and inversion parameters. The GUI can be
used either to format the inversion parameters and execute the
inversion code,
or to format input files. The inversion code can then
be run remotely from the command line. The input data format uses files
directly exported from Oasis Montaj, or can be formatted with a text
editor. The GUI has been compiled into a
stand alone windows executable. It also can be run in its native
language, MatLab.
Authors: Leif H. Cox and Michael S. Zhdanov
References:
Cox, L. H., and M. S. Zhdanov, 2007, Large Scale approximate 3D
inversion of HEM data using a moving footprint: Proceeding from the
Annual Meeting of the Consortium for Electromagnetic Modeling and
Inversion.
Cox, L. H., and M. S. Zhdanov, 2008a, Advanced computational methods of
rapid and rigorous 3D inversion of airborne electromagnetic data:
Communications in Computational Physics, 148, 160-179.
Cox, L. H., and M. S. Zhdanov, 2008b, Accounting for topography in 3D
inversion of airborne electromagnetic data: Proceedings of the Annual
Meeting, Consortium for Electromagnetic Modeling and Inversion.
Zhdanov, M. S., and E. Tartaras, 2002, Inversion of multi-transmitter
3-D electromagnetic data based on the localized quasi-linear
approximation: Geophysical Journal International, 148, 506-519.
MT3D_PRIN,
release March 2008.
The Matlab software package for 3D inversion of the magnetotelluric
(MT) data. This code inverts the principal components of the MT
impedance tensor -Zxy and Zyx. The data can be presented as either
observed apparent resistivities and phases or real and imaginary parts
of the impedances. The predicted data is calculated rigorously by
INTEM3D - integral equation (IE) modeling code (Hursan and Zhdanov,
2002). Fast Frechet derivative computation is based on quasi-analytical
approximation with variable background (QAVB) (Gribenko and Zhdanov,
2007a). 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, which produces smooth conductivity distributions. At the
cnonsequent stages (re-weightings) the user has a choice of minimum
norm, minimum support (Portniaguine and Zhdanov, 1999), minimum
vertical support (Gribenko and Zhdanov, 2007b) stabilizers, or their
combination. Appropriate selection of the stabilizing functional allows
the user to find a solution with sharp geoelectrical boundaries. The
code outputs the anomalous conductivity distribution, predicted
impedance data, and misfit values. The solution and predicted fields
can be visualized using the supplimentary software provided with the
code.
Authors: Alexander 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.
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.
Portniaguine, O. N., 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. Wilson and Sons.
Zhdanov, M. S., 2002, Geophysical inverse theory and regularization
problems: Elsevier.
LQL-interface,
release April 2003.
User friendly interface for
LQLINV3D code
Author: Ekaterina Tolstaya.
GRMAG-interface.
User friendly interface for
GRMAG3D code
