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
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/convert.sh) to process sequentially numbered
Density_*.ascii files, as documented in the comments in convert.sh. If you
don’t want this behavior, comment out lines 129-132 in text_to_obs.f90 and
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.
Sutton, Erik K., 2011: Accelerometer-Derived Atmospheric Density from the CHAMP and GRACE Satellites.