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Known problems
The following is a clearinghouse of known issues and caveats with links to
detailed descriptions or workarounds where available.
Imaging
- Incomplete
and/or inaccurate photometry at low galactic latitudes
- Overestimation of
sky levels near bright galaxies
- Bad CCD
columns
- Red leaks in
u-band
- Problems in u-band
sky determination
- Problems in the left-half of the u-band CCD in CamCol 3 in runs 2188,2189, 2190
Object catalogs
- Isophotal
radii in DR3-DR7 are given in pixels, not arcseconds
- SDSS and AB
magnitudes
- Sky
brightness values are extinction-corrected
- Sky
brightness values are given in maggies, not magnitudes
- Object
counts in tsField files are not meaningful
- A few runs
processed with slightly older version of photo.
Spectroscopy
- FIXED: Offset
of 0.35mag in spectrophotometry on 28 plates in
DR7's new spectral reductions
- Note on Radial Velocity zeropointing
- DR7 has improved
accuracy of stellar radial velocities
- Check redshift
status (zStatus) for reliability of redshifts
- Zero
equivalent width emission lines
- Main survey
spectra without tsTargets files or
target/targetInfo
entries in CAS
- Treatment of galactic
extinction correction in spectra
- Plates with
not-quite-perfect spectrophotometry
- Mismatches
between spectra and photometric data
- Reliability
of galaxy velocity dispersion measurements
- Bonus
plates with coverage extending beyond formal survey
area
- TileRun 60 boundaries in the DR5 CAS are inaccurate.
- Some bright sharp spectral lines become clipped
Last modified: Mon Jun 25 22:32:37 CEST 2007
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