Data Archive Server structure and contents
The Data Archive Server (DAS) is a file system containing all
survey data products. It is accessible via
This page mirrors the directory structure of the DAS, explaining
which files are found where. It links to the "data model" descriptions
of individual files. Directory names link to the http location, but
rsync server uses the same directory
structure. For more details, see the data model for directories.
The root directory contains a number of ASCII parameter files with names
fileList-*.par. These contain lists of all files in the
archive with a CRC checksum for each, and of all files which are
"missing" from the archive (i.e., you may expect to find these, but
they do not exist).
The root directory for imaging. It contains two kinds of
inchunk directories containing the calibrated object lists, and one
directory for every run/rerun pair
containing the remaining imaging data.
For either inchunk_best or inchunk_target, be sure to read the caveats on the
calibrated object lists page.
The imaging is done along great circles.
A unique covering of the sky is ensured by dividing these great circles
Calibrated object lists for every chunk are stored in subdirectories with names:
is the stripe number,
MMMMMM is the starting mu
coordinate for that chunk, and S is the sky version (
S = 1
indicates the best version and
S = 0 indicates the target version).
Every stripeNN_muMMMMMM_S directory contain the following:
- Six sub directories (numbered 1 through 6), one per camera column, containing object lists
mask subdirectory containing
csv imaging masks.
Note the csv masks are generated from the
which are stored in the corresponding run/rerun directory (see below).
Every best chunk stripeNN_muMMMMMM_1 directory contains the following files:
Every target chunk stripeNN_muMMMMMM_0 directory contains the following files:
These directories have names of the form
where RRRR is the run
number and EE is the rerun
number, eg. /DR6/data/imaging/1336/40 .
Every run/rerun directory contains two types of subdirectories:
- Directories which contain only files:
astrom -- results of the astrom pipeline
nfcalib -- results of photometric calibration
- Directories with one subdirectory per
camera column (1-6),
containing the bulk of the imaging data:
corr -- corrected frames
ie. reduced survey images
objcs -- further outputs of photometric pipeline:
fpC*.jpeg images of the
sky in various zoom levels
spectro2d pipeline output, produced by rerun 25 of the
spectro pipelines: the calibrated spectra. Contains one directory per
plate with name:
where PPPP is the plate number (eg. /DR6/data/spectro/2d_25/0644).
Every directory contains
- one spPlate*.fit file with all
640 calibrated spectra (and the subtracted sky spectra since DR6) for
- the spCFrame*.fit files with
individual 15-minute exposures
specBS (Princeton) spectral reductions:
Calibrated spectra (including gif and ps plots) and
classifications, redshifts, and other measured parameters (line fits,
velocity dispersions, line indices). Contains one directory per
plate with name:
where PPPP is the plate number
Every plate directory contains two subdirectories:
1d -- contains 640 spSpec*.fit files,
one per spectrum, containing the spectrum and all derived parameters.
gif -- contains
for every spectrum, with line annotations
Spectra + imaging
See separate page about
getting spectra in bulk.
Stellar parameter outputs
Last modified: Thu Oct 18 09:21:10 CEST 2007