Welcome to the DESI Data Model!
The DESI Data Tree
These pages define the directory structure and file formats for DESI
data products relative to a root directory DESI_ROOT.
Each data release has its own DESI_ROOT, e.g. the
Data Release 1
at https://data.desi.lbl.gov/public/dr1.
Data Directories
Directories under DESI_ROOT:
spectro/redux/SPECPROD/: Processed spectra, classifications, and redshifts
survey/catalogs/RELEASE: The Large Scale Structure catalog and associated mock catalogs
vac/RELEASE/: Value Added Catalogs
target/: Target selection and fiber assignment catalogs
spectro/data/NIGHT/EXPID/: Raw data
The following directories are more expert-level (e.g. pipeline calibration inputs) and are documented for DESI collaboration internal use and may not be included in data releases:
survey/ops/surveyops/: Data files used for day-to-day survey operations
spectro/desi_spectro_calib/: Spectrograph calibration data
protodesi/: Data and logs from the ProtoDESI campaign (no spectra)
$DESISURVEY_OUTPUT: Outputs from desisurvey and surveysim
$DESI_SPECTRO_SIM: Simulated spectro data
$DESIMODEL: Data used for simulating DESI
Other information
Bitmask definitions and environment variables used by the DESI data pipelines:
Imaging data and their catalogs are documented separately by the Legacy Survey.
The desidatamodel package on GitHub includes the data model input files and some Python utility code for generating and checking data model files. These links will be useful for developers:
References
Target Selection: Myers, A. D., et al. 2023, AJ 165, 50
Spectroscopic Pipeline: Guy, J., et al. 2023, AJ 165, 144
Early Data Release: DESI Collaboration et al. 2024, AJ 168, 58
Data Release 1: DESI Collaboration et al. 2025, submitted