Convert your observations into DART’s obs_seq file format

DART has a proprietary file format used to contain observations called an obs_seq or observation sequence file.

This file format is necessary because ensemble data assimilation techniques require that each observation has a specified observation error variance in order to apply Bayes’ Theorem during the assimilation.

DART provides source code to compile a type of executable known as an observation converter that takes source data and creates a suitable obs_seq file for assimilation.

It is possible that there is already source code in the repository to compile an observation converter for the data you intend to assimilate.

Examine the obs_converters directory to see if there is already a converter for your source data:

cd DART/observations/obs_converters
ls
AIRS          GSI2DART        SIF
Ameriflux     GTSPP           snow
AURA          MADIS           SSEC
AVISO         MIDAS           SST
CHAMP         MODIS           SSUSI
cice          MPD             tec
CNOFS         NASA_Earthdata  test_obs
CONAGUA       NCEP            text
COSMOS        NSIDC           text_GITM
DWL           obs_error       tpw
even_sphere   ocean_color     tropical_cyclone
GMI           ok_mesonet      USGS
gnd_gps_vtec  quikscat        utilities
GOES          radar           var
gps           README.rst      WOD
GPSPW         ROMS
GRACE         SABER

Comprehensive descriptions are also available in the Available observation converter programs page in the DART documentation.