The core LETKF solver will output several fields of diagnostic information at the end of the program if enabled in the yaml configuration file. See :ref:`solver.save_diag<configuration_solver>` and :ref:`solver.diag_file<configuration_solver>` configuration sections.
These help get a sense of how many observations are being used by each grid-point.
- col_maxhz - the maximum horizontal search radius for the grid column
- col_obscount - the number of observations, for each grid column, that were found within the given col_maxhz radius
- lg_obscount - the subset of observations that were allowed to be used for each localization group
- lg_obsloc - the sum of the localization values for observations used by each localization group. A single observation can have a localization value between 0.0 and 1.0. This gives a general sense of the amount of impact observations have.
If the :ref:`configuration_localization_loc_ocean` is used, additional fields will be saved to diagnose how vertical localization is performed.
- vtloc_surf_lvl - the depth, in number of levels, of the surface localization group
- vtloc_surf_depth - The depth, in meters, of the surface localization group