Tools for data access
DR4 data are distributed via the Catalog Archive
Server (CAS), an SQL database with fast search capabilities, and
the Data Archive Server (DAS), a collection of fits
images and tables containing the outputs of the imaging and
spectroscopic reduction pipelines. In addition, the SDSS collaboration
has created catalogs and other data products based on public survey
data that we link from our Value
Added Data Products page.
Catalog Archive Server (CAS) Search
|Catalog Archive Server
||The Catalog Archive Server offers efficient search tools for
querying the imaging and spectro catalogs from SDSS.
|Spectro Query Server
||Search spectra by
position, or by spectral or photometric parameters. Retrieve survey
|Imaging Query Server
||Search photometry catalog by position or by photometric
parameters. Retrieve survey files.
||Upload plate,MJD,fiber list as part of a SQL query
||Find SDSS matches for a list of objects.
||Directly search the database using your own SQL queries (also see
skyserver help pages).
||Use this batch job server for direct SQL searches of the
database with generous timeout setting. Share result sets with your
||Point and click on SDSS images.
||Generate jpeg finding charts from SDSS images.
||Get jpeg cutouts of SDSS imaging for object lists with link to
finding chart. Option to generate object list from SQL
In addition to using the web interfaces above, you can directly
connect to the database server to perform your own SQL queries using
||Provides GUI to edit and submit SQL queries
||python script to submit
SQL queries from the command-line
||Submit SQL queries from an emacs buffer
Data Archive Server (DAS)
- images of the night sky ("corrected frames")
in fits and jpeg format
- calibrated object lists with photometric
parameters as fits binary tables
- reduced spectra and spectral parameters as fits
binary tables and ps/gif plots
Files and directories within the DAS are designated by survey
identifiers of the desired data:
run/rerun/camcol/field for imaging;
plate/MJD/fiberID for spectroscopy. The easiest way to
obtain this designation is by one of the query forms provided. The DAS is
described in detail on the DAS structure
and contents page.
| FOOT DR4
||Check whether coordinate is in DR4 for arbitrary
(list of) RA,DECs; if so, retrieve
|DAS retrieval form
||Use query forms above to obtain
survey designation of required data to be uploaded here.
Small result sets will be
returned as .tar or .zip archive; larger sets can be
downloaded using http or rsync (see rsync help). The coverage page explains runs,
|http access to DAS
||Recommended method for creating new whole or partial mirrors
and individually selecting specific files. Use your web browser or
other http clients like
Recommended options for
wget to mirror entire directories:
--no-host-directories -l inf -r -np --continue
||Recommended method to updating existing mirrors. The rsync URL is
rsync://firstname.lastname@example.org/DR4. See the rsync help page.
|Spectra in bulk
||Get all spectroscopic data, or redshift lists by object type (galaxies, quasars, stars)
Last modified: Wed Jun 29 17:23:14 CDT 2005