Get Data

Spectroscopic Data

Optical Data

The SDSS optical spectra are split into several versions:

Catalogs of parameters derived from the SDSS-V (Run2d: v6_0_4) optical spectra (described via its datamodel) can be directly downloaded via https://dr18.sdss.org/sas/dr18/spectro/boss/redux/v6_0_4/ or via the wget command (40 MB): 

wget --spider https://dr18.sdss.org/sas/dr18/spectro/boss/redux/v6_0_4/spAll-v6_0_4.fits

In addition, the combined eFEDS spectra have a parallel summary file that can be obtained via the wget command (54 MB):

wget --spider https://dr18.sdss.org/sas/dr18/spectro/boss/redux/eFEDS/spAll-v6_0_4-eFEDS.fits

The SDSS I-IV (SDSS/BOSS/SEQUELS/eBOSS) optical spectra (Run2d: 26,103,104,v5_13_2) and matched to photometric data are documented on the optical spectra data page. These can be directly downloaded from the links on that page, or via wget commands. For example, to download the redshifts and classifications of all SDSS I-IV spectra (6.7 GB – Note: This is unchanged since DR17):

wget --spider https://dr17.sdss.org/sas/dr17/sdss/spectro/redux/specObj-dr17.fits

Or to get the SDSS (I-IV) associated photometric position-based matches (16 GB – Note: This is unchanged since DR17):

wget --spider https://dr17.sdss.org/sas/dr17/sdss/spectro/redux/photoPosPlate-dr17.fits

The stellar parameter (SSPP) results can be downloaded similarly (1.8 GB – Note: This is unchanged since DR12):

wget --spider https://dr18.sdss.org/sas/dr18/prior-surveys/sdss3-dr12-sdss/sspp/ssppOut-dr12.fits

Optical Spectra Per-Object Files

If you want a subset of the spectra, the most convenient form may be the spec files with one file per PLATE-MJD-FIBER containing the coadded spectrum, the redshift and classification fits, spectral line fits, and optionally the individual exposures which contributed to the coadd. These are located at:

Beneath each of those directories, the spectra are organized by plate in the form

PLATE/spec-PLATE-MJD-FIBER.fits

e.g.,

  3586/spec-3586-55181-0016.fits
3609/spec-3609-55201-0646.fits
3661/spec-3661-55614-0020.fits
...

To download these spectra in bulk, generate a list of spectra you wish to download in a text file of that format and then use wget:

  wget --spider -nv -r -nH --cut-dirs=7 \
-i speclist.txt \
-B https://dr18.sdss.org/sas/dr18/spectro/boss/redux/v6_0_4/spectra/full/

Infrared Data

DR18 does not include infrared spectra beyond those released with DR17.

Prior Surveys

Imaging Data

Images and derived catalog data are described on the imaging data page. You can use a SkyServer search or the file window_flist.fits file to identify which RERUN-RUN-CAMCOL-FIELD overlaps your region of interest. Then download the matching calibObj files (catalog data) or frame files (calibrated imaging data), e.g., for RERUN 301, RUN 2505, CAMCOL 3, FIELD 38, the r-band image is:

wget --spider https://dr18.sdss.org/sas/dr18/prior-surveys/sdss4-dr17-eboss/photoObj/frames/301/2505/3/frame-r-002505-3-0038.fits.bz2

and the associated catalog of identified galaxies for that patch of sky is:

wget --spider https://dr18.sdss.org/sas/dr18/prior-surveys/sdss4-dr17-eboss/sweeps/dr13_final/301/calibObj-002505-3-gal.fits.gz
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