obs_common_subset.f90 comments #1196

Activity

1. hkershaw-brown commented on Nov 2, 2026

   

   hkershaw-brown

   on Nov 2, 2026

   CollaboratorAuthor

   More actions

   A lot (all?) of these observation sequence programs maybe better done in pyDARTdiags.

   https://docs.dart.ucar.edu/en/latest/assimilation_code/programs/readme.html

   Creating Observation Sequence Files
   create_obs_sequence
   Creates a short andor synthetic observation sequence file using values read from standard input.
   
   create_fixed_network_seq
   Reads observation sequence file information from standard input and replicates it multiple times in a second observation sequence file, at user specified dates.
   
   obs_utils/create_obs_grid
   Create a set of observations located on a regular grid. Obs have no data values, but they are time ordered.
   
   obs_utils/obs_timejitter
   Randomly perturb the times of the observations in a (usually) set_def.out file. Writes the results to (usually) obs_seq.in.
   
   Querying Observation Sequence Files
   obs_utils/obs_info
   Summarize obs types, times, counts found in observation sequence file(s).
   
   obs_utils/obs_assim_count
   Prints out a quick table of obs types and counts, overall start and stop times, and metadata strings and counts. See obs_diag for more. There is an older version in the obs_assim_count directory.
   
   obs_seq_coverage
   Queries a set of observation sequence files to determine which observation locations report frequently enough to be useful for a verification study.
   
   obs_total_error
   Prints the total error in the mean and spread from an obs_seq file which has been through both perfect_model_obs and filter, so it has copies ‘truth’, ‘ensemble mean’, and ‘ensemble spread’. You can get more information by running the obs_diag program.
   
   Changing Observation Sequence Files
   obs_sequence_tool
   Subsets, combines, or alters observations from one or more observation sequence files and optionally writes them into a single output obs_seq file.
   
   obs_loop
   A template to read in observations from one obs_seq file and write them, optionally modified by user supplied code, to another obs_seq file.
   
   obs_utils/obs_sort
   Do a complete sort of an obs_seq file by location, observation type, then variance. An ancestor of obs_remove_dups.
   
   obs_utils/obs_remove_dups
   Removes duplicate observations from an obs_seq file, which involves a complete sort by time, location, observation type, then variance.
   
   obs_selection
   Extracts observations out of one or more obs_sequence files according to a list of observation types, times, and locations. The list is usually created by obs_seq_coverage, but can be an observation sequence file.
   
   obs_common_subset
   Select the subset of observations, which were successfully assimilated, from two or more assimilation cases (which used the same obs_seq.out file).
   
   obs_keep_a_few
   Creates an output observation sequence file that is shorter than the input obs_seq file.
   
   obs_seq_verify
   Reorders the observations from a forecast run of DART into a structure that is amenable for the evaluation of the forecast.
   
   obs_utils/obs_data_denial
   THIS IS NOT YET DONE! Help implement a data-denial experiment by randomly changing the error variance of N of each obs type in an observation sequence file to a huge value.