Sample dataset: Global gravity from ICGEM

[leouieda]

Description of the desired feature

A global gravity grid from an ICGEM spherical harmonic model (like EIGEN-6c4) would be great to showcase our gravity processing and any global methods, like tesseroid topographic correction. This should be an xarray.Dataset with raw gravity (no corrections), latitude, longitude, and ellipsoid height. To make things easier, gravity should probably be calculated on top of topography so that Bouguer corrections work reasonably.

[santisoler]

@leouieda
I'll be glad to get into this issue.
By the way, I can use this sample dataset to write an example for the load_icgem_gdf() function that is currently being written in #11.

We just need to propose a region of the world.
In the past we have used the Alps and Hawaii, maybe some region of the Southern hemisphere would make a more inclusive Fatiando!
We could ask for ideas in gitter if you agree.

[leouieda]

@santis19 I actually wanted this to be a global dataset. It's a good way to show off the normal gravity corrections etc. I don't know if there is a need to keep a sample dataset for load_icgem_gdf because storing the data as ASCII text is really inefficient and we want these sample data to be as small as possible.

We should have more regional data as well to show-off methods in that scale. For example, some data around the Neuquén basin would be great for basin inversions, etc, 😉