This is a modification of a standard text_to_obs converter that comes that comes with DART.

This observation converter reads CHAMP and GRACE density files, as described in Sutton (2011) 1 and outputs obs_seq files that can be assimilated using DART.


If an obs_seq.out file already exists, this converter automatically adds new observations to that file without deleting it. This is done to allow the wrapper script (work/ to process sequentially numbered Density_*.ascii files, as documented in the comments in If you don’t want this behavior, comment out lines 129-132 in text_to_obs.f90 and rebuild.


Please inspect the text_to_obs_nml namelist in work/input.nml to ensure the input and output filenames are specified properly.


The work/Density_3deg_02_335.ascii file is truncated to 2 datapoints merely to demonstrate the format. It isn’t meant to be used for real experiments.


Thank you to Alexey Morozov for contributing this observation converter.



Sutton, Erik K., 2011: Accelerometer-Derived Atmospheric Density from the CHAMP and GRACE Satellites.