pedromundo / tesseroids

Forward modeling of gravity fields in spherical coordinates

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Forward modeling of gravitational fields in spherical coordinates.

Developed by Leonardo Uieda in cooperation with Carla Braitenberg.

About

Tesseroids is a collection of command-line tools for modeling the gravitational potential, acceleration, and gradient (Marussi) tensor.

The mass models can be made of right rectangular prisms or tesseroids (spherical prisms). Computation for rectangular prisms can be made in Cartesian or spherical (geocentric) coordinates.

License

Tesseroids is free software made available under the terms of the BSD 3-clause license. See LICENSE.txt.

Citing

Tesseroids is research software made by scientists. If you use it in your research, please cite our Geophysics paper in your publications:

Uieda, L., V. Barbosa, and C. Braitenberg (2016), Tesseroids: Forward-modeling gravitational fields in spherical coordinates, GEOPHYSICS, F41-F48, doi:10.1190/geo2015-0204.1.

You can download a copy of the paper PDF at leouieda.com/papers/paper-tesseroids-2016.html and see all source code used in the paper at the Github repository pinga-lab/paper-tesseroids.

See CITATION.txt or the Citing page of the documentation for more information.

Installing

The easiest way to install is to download the latest compiled binary distribution from:

https://github.com/leouieda/tesseroids/releases/latest

We offer binaries for Windows (32 and 64 bit) and GNU/Linux (32 and 64 bit).

Once downloaded, simply unpack the archive in the desired directory. The executables will be in the bin folder. For easier access to the programs, consider adding the bin folder to your PATH environment variable.

Getting started

Take a look at the examples in the Cookbook. They contain scripts that run Tesseroids and some Python code to plot the results.

The documentation contains sections on the theory and equations and usage instructions.

Also, all programs accept the -h flag to print the instructions for using that particular program. For example:

$ tessgrd -h
Usage: tessgrd [PARAMS] [OPTIONS]

Make a regular grid of points.

All units either SI or degrees!

Output:
  Printed to standard output (stdout) in the format:
    lon1    lat1    height
    lon2    lat1    height
    ...     ...     ...
    lonNLON lat1    height
    lon1    lat2    height
    ...     ...     ...
    ...     ...     ...
    lonNLON latNLAT height

  * Comments about the provenance of the data are inserted into
    the top of the output

Parameters:
  -r           W/E/S/N: Bounding region of the grid.
  -b           NLON/NLAT: Number of grid points in the
               longitudinal and latitudinal directions.
  -z           HEIGHT: Height of the grid with respect to the
               mean Earth radius.
  -h           Print instructions.
  --version    Print version and license information.

Options:
  -v           Enable verbose printing to stderr.
  -lFILENAME   Print log messages to file FILENAME.

Part of the Tesseroids package.
Project site: <http://fatiando.org/software/tesseroids>
Report bugs at: <http://code.google.com/p/tesseroids/issues/list>

Getting help

Write an e-mail to Leonardo Uieda, or tweet, or Google Hangout. Even better, submit a bug report/feature request/question to the Github issue tracker.

Compiling from source

If you want to build Tesseroids from source, you'll need:

• A C compiler (preferably GCC)
• The build tool SCons

Setting up SCons

Tesseroids uses the build tool SCons. A SConstruct file (Makefile equivalent) is used to define the compilation rules. The advantage of SCons over Make is that it automatically detects your system settings. You will have to download and install SCons in order to easily compile Tesseroids. SCons is available for both GNU/Linux and Windows so compiling should work the same on both platforms.

SCons requires that you have Python installed. Follow the instructions in the SCons website to install it. Python is usually installed by default on most GNU/Linux systems.

Under Windows you will have to put SCons on your PATH environment variable in order to use it from the command line. It is usually located in the Scripts directory of your Python installation.

On GNU/Linux, SCons will generally use the GCC compiler to compile sources. On Windows it will search for an existing compiler. We recommend that you install GCC on Windows using MinGW.

Compiling

Download a source distribution and unpack the archive anywhere you want (e.g., ~/tesseroids or C:\tesseroids or whatever). To compile, open a terminal (or cmd.exe on Windows) and go to the directory where you unpacked (use the cd command). Then, type the following and hit Enter:

scons

If everything goes well, the compiled executables will be placed on a bin folder.

To clean up the build (delete all generated files), run:

scons -c

If you get any strange errors or the code doesn't compile for some reason, please submit a bug report. Don't forget to copy the output of running scons.

Testing the build

After the compilation, a program called tesstest will be placed in the directory where you unpacked the source. This program runs the unit tests for Tesseroids (sources in the test directory).

To run the test suite, simply execute tesstest with no arguments:

tesstest

or on GNU/Linux:

./tesstest

A summary of all tests (pass or fail) will be printed on the screen. If all tests pass, the compilation probably went well. If any test fail, please submit a bug report with the output of running tesstest.