GrafLab and isGrafLab cookbook.
Provided are HOWTOs, showing basic and advanced applications using the command line. The cookbook is centered around gravity field modelling, but included are several tricks to exploit the routines beyond their original intention (planetary topographies, etc.).
The HOWTO files are ordinary MATLAB scripts. A pre-compiled cookbook consists
of Live Scripts that can be found inside the src directory and their PDF and
HTML versions that are stored inside the docs folder.
GrafLab (GRAvity Field LABoratory) is a MATLAB-based routine to compute gravity field quantities up to high degrees (tens of thousands and beyond) from spherical harmonic gravity models. Computed can be, for instance, the geoid, the height anomaly, gravity anomalies/disturbances, deflections of the vertical or the gravitational tensors.
isGrafLab (Irregular Surface GRAvity Field LABorary) is a modified version of GrafLab that efficiently computes gravity field quantities at dense grids residing on irregular surfaces, such as the Earth's surface.
Each HOWTO has its own source code. Beginners should go through the HOWTOs in
the order they are numbered. Advanced users may pick whatever HOWTO they are
interested in. In any case, you must start by executing the init.m
script from the src directory. It downloads the source codes of GrafLab and
isGrafLab and some input data.
If you are not familiar with the GrafLab command line interface, you may want to go here, learn the interface at first and then return back.
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g01: Synthesis at grids and at scattered points
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g02: Gravitational field models
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g03: Minimum and maximum harmonic degree of the synthesis
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g04: Methods to compute the Legendre functions
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g05: Plotting in GrafLab and the output variable
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g06: Synthesis of planetary topographies
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g07: Stop the Earth's rotation to get gravitational quantities
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g08: Grids with varying spacings in latitudes and longitudes
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g09: Exploit the symmetry of Legendre functions
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g10: Commission error
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g11: A trick with the minimum and the maximum degree of the synthesis
If you are not familiar with the isGrafLab command line interface, you may want to go here, learn the interface at first and then return back.
- i01: Synthesis at grids residing on the Earth's topography
Contributions of any kind are welcome!
Feel free to contact the author, Blazej Bucha, at blazej.bucha@stuba.sk.
GrafLab
- Bucha, B., Janák, J., 2013. A MATLAB-based graphical user interface program for computing functionals of the geopotential up to ultra-high degrees and orders. Computers & Geosciences 56, 186-196, https://doi.org/10.1016/j.cageo.2013.03.012
isGrafLab
- Bucha, B., Janák, J., 2014. A MATLAB-based graphical user interface program for computing functionals of the geopotential up to ultra-high degrees and orders: Efficient computation at irregular surfaces. Computers & Geosciences 66, 219-227, https://doi.org/10.1016/j.cageo.2014.02.005