If you want to work with data that was released in SDSS-IV or earlier, then check the Completed Surveys page for direct links to data descriptions, caveats, and relevant tutorials. Completed surveys include: We have tutorials available on parameter files, fits files, and using bitmasks, and a page with conversions between our wavelength and magnitude […]
Search Results for: SDSS-IV
Bulk Data Downloads
All data can be downloaded directly from data.sdss.org or dr19.sdss.org using the wget command, but is more efficiently downloaded from the SDSS data transfer node from dtn.sdss.org using the rsync method. Access is also available via Globus Online. The Data Model page has a description of the directory structure and file formats. Note that the […]
Data Volume
SDSS Science Archive Server (SAS) The SAS is a hierarchical directory structure with named data products, and can be navigated directly: Individual data products are either replacements from previous data releases, and add incrementally to the data volume, or contain links to previous data releases, and add cumulatively to the data volume. Whether you are […]
Get Data
Spectroscopic Data There are several ways to get to the Spectroscopic Data. Below we list several ways for you to download spectra and catalogs, with the caveat that for large downloads we have additional information on the Bulk Download Page. Alternative ways to access spectra and catalogs are through: The SDSS optical spectra are split […]
Bitmasks
SDSS makes heavy use of the concept of a bitmask in spectroscopic target flags and other contexts. For the actual bit values for all SDSS flags, see the lists below. More detailed descriptions of the targeting bitmasks for the completed optical surveys and infrared surveys can be found in the DR17 release documentation. The page […]
Glossary of SDSS Terminology
This Glossary is a work in progress, and more terms will be added during the lifetime of SDSS-V. If you have come across SDSS Terminology that is not explained yet in the Glossary below, then please let us know via the SDSS Helpdesk at helpdesk@sdss.org. ABCDEFGHIJKLMNOPQRSTUVWXYZ A Adaptive Moment A method of measuring object shapes […]
Frequently Asked Questions
About the SDSS What is the Sloan Digital Sky Survey? The Sloan Digital Sky Survey is an ongoing astronomy project that has been working since 1998 to make a detailed map of the universe, including our Milky Way galaxy. What data does SDSS have? What can SDSS tell me about the sky? The SDSS releases […]
Using Bitmasks
A bit mask uses the bits in the binary representation of an integer as “toggles” to indicate whether certain conditions are met. For a more general introduction to this concept, consult Wikipedia or other online resources on the subject. Within the SDSS, the most common use of a bitmask is to indicate the status of […]
Plates
Plates in the SDSS context are round pieces of aluminum with holes in them to plug the fibers that collect the light from each astrophysical object. From 1999 through 2021, SDSS used these plug plates to perform our observations. These plates needed to be designed and drilled with a few months in advance so that […]
Software Pipelines
Current Pipelines In SDSS-V DR19, we have data from the BOSS, APOGEE, and LVMi instruments processed through several automated pipelines. The following table lists the current SDSS pipelines: Pipeline Instrument Mapper APOGEE Reduction Pipeline APOGEE MWM BOSS Reduction Pipeline (IDLspec2D) BOSS BHM, MWM LVM Data Reduction Pipeline LVMi LVM ASTRA Data Analysis Pipeline BOSS+APOGEE MWM […]