find_file_triplets, uses list_duplicates to find OSCAR .nc files with the same aquisition time (from filename, currently) and combine the three beam files as a triplet of indices
antenna_ident uses identify_antenna_location to use the processed doppler to find which beam each dataset belongs to
load_OSCAR_data to read in the triplet of .nc files into a dataset dict
Changes to merge_beams to merge the dict of datasets, assigning Antenna dimensions based on antenna_idents
fill_missing_variables to get around missing variables between datasets. This is a running repair and should be obsolete when we find a better way of doing it within xarray.
New small functions to: