CRTomo - Complex Resistivity Tomography

Warning

CRTomo is a legacy research code - use it for reference, or after contacting the authors with regard to a special use case. Otherwise, please use actively maintained alternatives!

CRTomo is a finite-element forward (CRMod) and inversion (CRTomo) code for complex electrical impedance data, written in Fortran. The code was originally developed by Prof. A. Kemna ([email protected]), and has been extended in various scientific projects (see AUTHORS file for a complete list of contributors -- the git history does not reflect the true contribution history!). Please refer to the section scope to assess whether you want to use the code or not. The code is distributed under the MIT open-source licence (see section below).

Main features:

• support for 2D and 2.5D (constant y-resistivity distribution) forward and inverse modeling
• support for quadratic and triangular meshes with topography
• support for modeling/inversion of the complex impedance, i.e. magnitude and phase values
• support for various regularization schemes (smooth, anisotropic in x/z directions, MGS)
• works on Windows and Linux

At the moment we do not publish binaries. You have to compile the code by yourself to use it.

A companion project provides a work-in-progress python interface for the code (https://github.com/geophysics-ubonn/crtomo_tools).

Documentation

Documentation and installation instructions (so far as it exists) can be found here for CRTomo:

https://geophysics-ubonn.github.io/crtomo_docs_all/crtomo_doc/index.html

Documentation for the crtomo_tools can be found here:

https://geophysics-ubonn.github.io/crtomo_docs_all/crtomo_tools/index.html

Note that these links point to static versions of the documentation, and are not necessarily updated regularly.

Scope

CRTomo has reached a mature state and at this point new features are only added sporadically. If you are looking for a well-tested 2D/2.5D complex resistivity inversion code, CRTomo could be something for you.

If you are new to electrical inversion and are looking for a general purpose inversion code/framework, have a look at:

• ResIPy: https://resipy.org/getting-started.html
• PyGimli: (www.pygimli.org) and its associated electrical inversion framework BERT (https://gitlab.com/resistivity-net/bert).

Getting help

We appreciate any suggestions, improvements, and bug reports via the github interfaces (issues, merge requests). Due to time constraints in the in general we cannot provide detailed usage help. However, if you have interesting research applications and would like to use CRTomo, drop us a line and lets see what we can do.

In technical matters please contact Maximilian Weigand ([email protected]).

For research proposals/larger collaborations, please contact Prof. A. Kemna ([email protected]).

Cite as

For scientific research we would ask you to attribute usage using the following citation:

Kemna, A.: Tomographic inversion of complex resistivity – theory and
application, Ph.D.  thesis, Ruhr-Universität Bochum,
doi:10.1111/1365-2478.12013, 2000.

For technical documentation please cite either the full git commit hash, or (if available) a specific release with its DOI.

License

CRTomo and its components, if not otherwise stated, is distributed under the MIT license. Please refer to the file COPYING for further information.

Installation

For detailed installation instructions, please refer to: https://geophysics-ubonn.github.io/crtomo_docs_all/crtomo_doc/misc/installation.html

If you are working under Linux with a git repository, run

./autogen.sh

once to generate the necessary autotools files.

Otherwise, configure, compile, and install the program with

./configure
make
make install

The default installation path points to $HOME/bin. You can change the installation directory with

./configure --prefix=$HOME/inst/

Run

./clean_autotools.sh

to remove all auto-generated files.

Distribution

After running ./configure, a source archive called "crtomomod*.tar.gz" can be generated using

make dist

Debian Packaging

The command

./prep_deb_package.sh

creates a Debian package in the "package/" subdirectory.

The version number can be set in configure.ac, and a new entry in debian/changelog must be created.

Limiting CPU usage

CRTomoMod is compiled using openmp. The number of CPU cores that are facilitated can be controlled using the following environment variables:

export OMP_THREAD_LIMIT=1
export OMP_NUM_THREADS=1
export OPENBLAS_NUM_THREADS=1

TODO

We should restrict the calling of external shell scripts (git version, error messages, etc) to the ./autogen.sh script, and remove them from configure.ac. This simplifies the Debian package generation.