Clessig/develop/synop datareader

[clessig]

Description

Data reader for station-like data in simple netCDF format

Type of Change

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Documentation update

Issue Number

Closes #862

Code Compatibility

• I have performed a self-review of my code

Code Performance and Testing

• I ran the uv run train and (if necessary) uv run evaluate on a least one GPU node and it works
• If the new feature introduces modifications at the config level, I have made sure to have notified the other software developers through Mattermost and updated the paths in the $WEATHER_GENERATOR_PRIVATE directory

Dependencies

• I have ensured that the code is still pip-installable after the changes and runs
• I have tested that new dependencies themselves are pip-installable.
• I have not introduced new dependencies in the inference portion of the pipeline

Documentation

• My code follows the style guidelines of this project
• I have updated the documentation and docstrings to reflect the changes
• I have added comments to my code, particularly in hard-to-understand areas

Additional Notes

[tnipen]

I think we should force the user to set a _FillValue attribute in the NetCDF files if there are missing data. I forgot to do this with my file (well actually, if you are using the default fill value of 9.96921e+36, then you don't need to set the flag, however xarray doesn't recognize this).

When _FillValue is set, xr.open_dataset fill automatically convert missing values to NaNs.

[tnipen]

Line 91 can be removed now that the user specifically select channels

[tnipen]

Would it be useful to specify the requirements of the NetCDF file? Here is a suggestion:

Generic parser for station data in NetCDF format. The file must have 2 dimensions: time and location.
- Data variables must have dimensions in the following order (time, location). The names of the dimension can be anything.
- Geoinfo variables must have dimension (location,)
- Any variable with missing values must have the _FillValue attribute set
- A latitude and longitude variable with dimension (location,) must be provided. The units must be degrees and the variable name can be configured.
- A variable called time must be provided and have dimension (time,). Units must follow CF-conventions and the variable must have a units attribute.