SDSS DAS Version 2 new with DR7!
This is the SDSS DAS version 2 main page. DR6 DAS is no longer available. For
general information on the SDSS, please consult the
SDSS homepage. For more
inforation on using SDSS data, please consult the
SDSS DR7 web site.
The SDSS Data Archive Server (DAS) serves files produced and
consumed by the SDSS data processing pipelines. See
this overview of the pipelines for
a description of the pipelines, references to more detailed
information on them, and tables of what files are available in the DAS
and where to find them. For the online SQL database and more advanced
interactive data exploration tools, see the
Catalog Archive Server (CAS).
The DAS itself provides direct access to the
directory tree with the
data, interactive forms that allow users
to upload tables of data of interest for exploration of bulk
download, and web pages for browsing data release
7 and older data releases.
Interactive download tools
Each of these forms can be used either to browse a user specified data
set, or generate a list of URLs of files corresponding to that data set. You
can then save this list to disk, and use wget or any other bulk http
download utility (eg curl) to download the
whole list. If you saved the URL list an a file named sdss-wget.lis,
you can use wget to download the files into a directory structure
corresponding to that of the DAS with a command that looks like this:
bash$ wget -x -nH -i sdss-wget.lis
The -c and --cut-dirs options are also likely to be
of interest to DAS users; consult the wget documentation.
Mass download
through rsync is no longer
available.
Please contact webmaster@pha.jhu.edu if you have any questions or concerns.
Browse Data Release 7
- Browse the complete set of DR7 runs with all reruns, by stripe and by run.
- Browse DR7 legacy survey imaging, best rerun, by stripe and by run.
- Browse DR7 SEGUE survey imaging, best rerun, by stripe and by run.
- Browse DR7 supernova survey imaging, by
stripe and by run.
- Browse the DR7 equatorial stripe
coadd.
- Browse spectroscopy (rerun 26), organized by program or on one big page.
- Browse DR7 legacy survey imaging, target rerun, by stripe and by run.
- Browse DR7 SEGUE survey imaging, target rerun, by stripe and by run.
The DAS also includes Steve Kent's
SDSS mosaic interface.
You can also browse older data releases.
Working directly with the directories and files
You can also browse the raw directory structures:
- http://das.sdss.org/imaging
- holds the files generated by the imaging pipelines. The base URL
points to a directory of all imaging runs included in the DAS.
- http://das.sdss.org/spectro
- holds the files generated by the spectroscopic pipelines.
- http://das.sdss.org/pt
- holds the files generated by the photometric telescope pipeline,
mtpipe, including photometric soluctions and object catalogs.
- http://das.sdss.org/nightly
- holds the files generated at the observatory by MJD. These files
include the text night log, cloud camera images, and other
observing data.
- http://das.sdss.org/software
- holds source code for some of the software products used in the
survey. The directory holds the source code of the final (for SDSS-II) versions
of serveral key processing
pipelines. The CVSrepository
subdirectory holds tar files of the contents of the CVS repository
for most key products.
- http://das.sdss.org/va
- holds value added catalogs stored in the DAS.
- http://das.sdss.org/unprocessed
- holds the raw data files as they came from the
mountain.
From these directories, you can download files using an http
downloader such as wget. The total volumes of these directories can be found
here.
For example, to download all files for run 3836, rerun 41 using wget:
bash$ wget -r -nH -np -N -l inf http://das.sdss.org/imaging/3836/41/
where
- - the -r option requests that wget download recursively,
- - the -nH asks that the directory named after the host name of
the DAS not be created,
- - the -np prevents wget from following the ".." link
in the directory (which would have the undesired consequence of
downloading the entire DAS),
- - the -N tells wget not to re-download a file if a file with
the same name and size and a more recent date is already present,
and
- - the -l inf tells wget not to limit the depth of the directory structure.
You will probably want to explore the --cut-dirs and
--directory-prefix options to refine where wget stores the
files it retrieves. If you started a download which was then
interrupted, the -c option can be used to tell it to continue
partially downloaded files.
If you want a directory but not other files or subdirectories in its
parent, you must use the trailing slash in the URL!
Older Data Releases
- Browse spectroscopy (rerun 25, up to MJD 54468), organized by program or on one big page.
- Browse DR6 legacy survey imaging, best rerun, by stripe and by run.
- Browse DR6 legacy survey imaging, target rerun, by stripe and by run.
- Browse the DR6 spectroscopic archive.
- Browse DR5 legacy survey imaging, best rerun, by stripe and by run.
- Browse DR5 legacy survey imaging, target rerun, by stripe and by run.
- Browse the DR5 spectroscopic archive.
- Browse DR4 legacy survey imaging, best rerun, by stripe and by run.
- Browse DR4 legacy survey imaging, target rerun, by stripe and by run.
- Browse the DR4 spectroscopic archive.
- Browse DR3 legacy survey imaging, best rerun, by stripe and by run.
- Browse DR3 legacy survey imaging, target rerun, by stripe and by run.
- Browse the DR3 spectroscopic archive.
- Browse DR2 legacy survey imaging, best rerun, by stripe and by run.
- Browse DR2 legacy survey imaging, target rerun, by stripe and by run.
- Browse the DR2 spectroscopic archive.