Environment Variables

DESI data are grouped broadly by category, using environment variables to define the base directory under which files of that category are kept. These variables have a standard location relative to DESI_ROOT, but code uses these variables so that one can swap out different input/output locations for testing.

• $DESI_ROOT : represents the top level of the DESI directory tree.
• $DESI_SPECTRO_DATA : raw data
• $DESI_SPECTRO_REDUX : processed spectro data
• $DESI_SPECTRO_SIM : simulated spectro data
• $DESI_SPECTRO_CALIB : spectro calibration data
• $DESI_SURVEYOPS : data files used for day-to-day survey operations
• $DESI_TARGET : target selection and fiber assignment (see also Myers et al. 2023)
• $DESIMODEL : data used for simulating DESI
• $DESISURVEY_OUTPUT : outputs from desisurvey and surveysim
• $PROTODESI : data and logs from the ProtoDESI campaign